229 results on '"ParM"'
Search Results
2. The genetics of congenital central hypoventilation syndrome: clinical implications
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Bishara J, Keens TG, and Perez IA
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Congenital central hypoventilation syndrome ,PHOX2B ,polyalanine repeat mutation ,PARM ,NPARM ,Medicine (General) ,R5-920 ,Genetics ,QH426-470 - Abstract
John Bishara,1 Thomas G Keens,1,2 Iris A Perez1,2 1Division of Pediatric Pulmonology and Sleep Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA; 2Department of Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, USA Abstract: Congenital central hypoventilation syndrome (CCHS) is a rare genetic disorder of the autonomic nervous system (ANS) and respiratory control. This disorder, formerly referred to as Ondine’s curse, is due to a mutation in the PHOX2B gene that affects the development of the neural crest cells. CCHS has an autosomal dominant pattern of inheritance. Majority of the patients have a polyalanine repeat mutation (PARM) of the PHOX2B, while a small group has non-PARM (NPARM). Knowledge of the patient’s PHOX2B gene mutation helps predict a patient’s clinical presentation and outcome and aids in anticipatory management of the respiratory and ANS dysfunction. Keywords: diaphragm pacing, noninvasive positive pressure ventilation, genetic counseling, genetic testing, CCHS, PHOX2B, congenital central hypoventilation syndrome
- Published
- 2018
3. Overview of the Diverse Roles of Bacterial and Archaeal Cytoskeletons
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Amos, Linda A., Löwe, Jan, Harris, J. Robin, Series editor, Löwe, Jan, editor, and Amos, Linda A., editor
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- 2017
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4. Structure and Dynamics of Actin-Like Cytomotive Filaments in Plasmid Segregation
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Gayathri, Pananghat, Harne, Shrikant, Harris, J. Robin, Series editor, Löwe, Jan, editor, and Amos, Linda A., editor
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- 2017
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5. Protein-Nanocrystal Conjugates Support a Single Filament Polymerization Model in R1 Plasmid Segregation
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Choi, Charina L.
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Basic biological sciences ,Materials science ,Nanoscience and Nanotechnology ,protein-nanocrystal conjugates ,discrete DNA-Au nanoparticles ,ParM ,ParR1 system - Abstract
To ensure inheritance by daughter cells, many low-copy number bacterial plasmids, including the R1 drug-resistance plasmid, encode their own DNA segregation systems. The par operon of plasmid R1 directs construction of a simple spindle structure that converts free energy of polymerization of an actin-like protein, ParM, into work required to move sister plasmids to opposite poles of rod-shaped cells. The structures of individual components have been solved, but little is known about the ultrastructure of the R1 spindle. To determine the number of ParM filaments in a minimal R1 spindle, we used DNA-gold nanocrystal conjugates as mimics of the R1 plasmid. Wefound that each end of a single polar ParM filament binds to a single ParR/parC-gold complex, consistent with the idea that ParM filaments bind in the hollow core of the ParR/parC ring complex. Our results further suggest that multifilament spindles observed in vivo are associated with clusters of plasmids segregating as a unit.
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- 2008
6. Advances in Structural Biology and the Application to Biological Filament Systems.
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Popp, David, Koh, Fujiet, Scipion, Clement P. M., Ghoshdastider, Umesh, Narita, Akihiro, Holmes, Kenneth C., and Robinson, Robert C.
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FREE electron lasers , *CRYSTALLOGRAPHY , *ELECTRON microscopy , *CAPPING proteins , *TROPOMYOSINS , *TROPOMODULIN - Abstract
Structural biology has experienced several transformative technological advances in recent years. These include: development of extremely bright X‐ray sources (microfocus synchrotron beamlines and free electron lasers) and the use of electrons to extend protein crystallography to ever decreasing crystal sizes; and an increase in the resolution attainable by cryo‐electron microscopy. Here we discuss the use of these techniques in general terms and highlight their application for biological filament systems, an area that is severely underrepresented in atomic resolution structures. We assemble a model of a capped tropomyosin‐actin minifilament to demonstrate the utility of combining structures determined by different techniques. Finally, we survey the methods that attempt to transform high resolution structural biology into more physiological environments, such as the cell. Together these techniques promise a compelling decade for structural biology and, more importantly, they will provide exciting discoveries in understanding the designs and purposes of biological machines. [ABSTRACT FROM AUTHOR]
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- 2018
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7. Bacterial and archaeal cytoskeletons
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Yue Liu and Jan Löwe
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0301 basic medicine ,Bacteria ,ParM ,Protein design ,Biology ,Archaea ,MreB ,General Biochemistry, Genetics and Molecular Biology ,Cell biology ,Prokaryotic cytoskeleton ,Cytoskeletal Proteins ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Tubulin ,Prokaryotic Cells ,biology.protein ,General Agricultural and Biological Sciences ,Cytoskeleton ,FtsZ ,030217 neurology & neurosurgery ,Actin - Abstract
All living cells depend on the intricate organization of molecular components in space and time. Although this notion was historically based on eukaryotic cells, with their structured intracellular architecture and cellular morphologies, it is now recognized that prokaryotes (that is, bacteria and archaea) also possess complex structures. A cytoskeleton is a network of intracellular protein filaments that play a structural or mechanical role (such as scaffolding, pushing, or pulling) in the spatiotemporal organization of cellular processes. Polymerization of protein monomers in a roughly linear fashion into filaments represents an effective means to establish long-range spatial order by bridging the gap between nanometer-sized molecules and micron-sized cells. It is now evident that bacteria and archaea possess numerous kinds of cytoskeletal proteins, including prokaryotic homologues of the eukaryotic actins, tubulins, and intermediate filaments, as well as other types that have been found primarily or exclusively in prokaryotes (Table 1). Understanding the diverse functions and mechanisms of the rapidly growing universe of prokaryotic cytoskeletal proteins will not only advance prokaryotic cell biology and reveal evolutionary principles, but also open up new avenues for the development of anti-microbial agents, de novo protein design, and the construction of minimal and synthetic cells.
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- 2021
8. Structural complexity of filaments formed from the actin and tubulin folds
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Shimin Jiang, Umesh Ghoshdastider, Akihiro Narita, David Popp, and Robert C. Robinson
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actin ,evolution ,filaments ,ParM ,tubulin ,TubZ ,Biology (General) ,QH301-705.5 - Abstract
From yeast to man, an evolutionary distance of 1.3 billion years, the F-actin filament structure has been conserved largely in line with the 94% sequence identity. The situation is entirely different in bacteria. In comparison to eukaryotic actins, the bacterial actin-like proteins (ALPs) show medium to low levels of sequence identity. This is extreme in the case of the ParM family of proteins, which often display less than 20% identity. ParMs are plasmid segregation proteins that form the polymerizing motors that propel pairs of plasmids to the extremities of a cell prior to cell division, ensuring faithful inheritance of the plasmid. Recently, exotic ParM filament structures have been elucidated that show ParM filament geometries are not limited to the standard polar pair of strands typified by actin. Four-stranded non-polar ParM filaments existing as open or closed nanotubules are found in Clostridium tetani and Bacillus thuringiensis, respectively. These diverse architectures indicate that the actin fold is capable of forming a large variety of filament morphologies, and that the conception of the “actin” filament has been heavily influenced by its conservation in eukaryotes. Here, we review the history of the structure determination of the eukaryotic actin filament to give a sense of context for the discovery of the new ParM filament structures. We describe the novel ParM geometries and predict that even more complex actin-like filaments may exist in bacteria. Finally, we compare the architectures of filaments arising from the actin and tubulin folds and conclude that the basic units possess similar properties that can each form a range of structures. Thus, the use of the actin fold in microfilaments and the tubulin fold for microtubules likely arose from a wider range of filament possibilities, but became entrenched as those architectures in early eukaryotes.
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- 2016
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9. Evidence that compatibility of closely related replicons in Clostridium perfringens depends on linkage to parMRC-like partitioning systems of different subfamilies.
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Watts, Thomas D., Johanesen, Priscilla A., Lyras, Dena, Rood, Julian I., and Adams, Vicki
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CLOSTRIDIUM , *CLOSTRIDIUM perfringens , *BACILLACEAE , *EUBACTERIALES , *REPLICONS - Abstract
Clostridium perfringens produces an extensive repertoire of toxins and extracellular enzymes, many of which are intimately involved in the progression of disease and are encoded by genes on conjugative plasmids. In addition, many C. perfringens strains can carry up to five of these conjugative toxin or antimicrobial resistance plasmids, each of which has a similar 35 kb backbone. This conserved backbone includes the tcp conjugation locus and the central control region (CCR), which encodes genes involved in plasmid regulation, replication and partitioning, including a parMRC partitioning locus. Most conjugative plasmids in C. perfringens have a conserved replication protein, raising questions as to how multiple, closely related plasmids are maintained within a single strain. Bioinformatics analysis has highlighted the presence of at least 10 different parMRC partitioning system families ( parMRC A – J ) in these plasmids, with differences in amino acid sequence identity between each ParM family ranging from 15% to 54%. No two plasmids that encode genes belonging to the same partitioning family have been observed in a single strain, suggesting that these families represent the basis for plasmid incompatibility. In an attempt to validate the proposed parMRC incompatibility groups, genetically marked C. perfringens plasmids encoding identical parMRC C or parMRC D homologues or different combinations of parMRC A , parMRC C and parMRC D family homologues were introduced into a single strain via conjugation. The stability of each plasmid was determined using an incompatibility assay in which the plasmid profile of each strain was monitored over the course of two days in the absence of direct selection. The results showed that plasmids with identical parMRC C or parMRC D homologues were incompatible and could not coexist in the absence of external selection. By contrast, plasmids that encoded different parMRC homologues were compatible and could coexist in the same cell in the absence of selection, with the exception of strains housing parMRC C and parMRC D combinations, which showed a minor incompatibility phenotype. In conclusion, we have provided the first direct evidence of plasmid incompatibility in Clostridium spp. and have shown experimentally that the compatibility of conjugative C. perfringens plasmids correlates with the presence of parMRC -like partitioning systems of different phylogenetic subfamilies. [ABSTRACT FROM AUTHOR]
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- 2017
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10. Comparative data on emotional (psychotic) aggressive biting behavior in mice of ddY strain measured by using two devices; Aggressive response meter and powerlab-compatible type aggressive response meter.
- Author
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Igarashi K, Kuchiiwa S, Kuchiiwa T, Tomita K, and Sato T
- Abstract
The Aggressive Response Meter (ARM) has been validated for measuring emotional (psychotic) aggression triggered by mental irritation in mice. In the present article, we newly developed a device, pARM (PowerLab-compatible type ARM). We collected on the aggressive biting behavior (ABB) intensity and ABB frequency of 20 male and female mice of ddY strain studied over a period of 6 days by using pARM and the former ARM. We calculated Pearson's correlation between the values of pARM and those of ARM. The accumulated data can be referred as a basis for demonstrating the consistence of pARM and the former ARM, and used in future research to augment the understanding of stress-induced emotional aggression in mice., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)
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- 2023
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11. An overview of data fusion techniques for Internet of Things enabled physical activity recognition and measure
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Jun Qi, Po Yang, Zhong Zhao, Yun Yang, Lee Newcombe, and Xiyang Peng
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business.industry ,Computer science ,Wearable sensing ,ParM ,Physical activity ,020206 networking & telecommunications ,Timeline ,02 engineering and technology ,Sensor fusion ,Data science ,Hardware and Architecture ,Robustness (computer science) ,Signal Processing ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,business ,Internet of Things ,Software ,Wearable technology ,Information Systems - Abstract
Due to importantly beneficial effects on physical and mental health and strong association with many rehabilitation programs, Physical Activity Recognition and Measure (PARM) has been widely recognised as a key paradigm for a variety of smart healthcare applications. Traditional methods for PARM relies on designing and utilising Data fusion or machine learning techniques in processing ambient and wearable sensing data for classifying types of physical activity and removing their uncertainties. Yet they mostly focus on controlled environments with the aim of increasing types of identifiable activity subjects, improved recognition accuracy and measure robustness. The emergence of the Internet of Things (IoT) enabling technology is transferring PARM studies to an open and dynamic uncontrolled ecosystem by connecting heterogeneous cost-effective wearable devices and mobile apps and various groups of users [35] . Little is currently known about whether traditional Data fusion techniques can tackle new challenges of IoT environments and how to effectively harness and improve these technologies. In an effort to understand potential use and opportunities of Data fusion techniques in IoT enabled PARM applications, this paper will give a systematic review, critically examining PARM studies from a perspective of a novel 3D dynamic IoT based physical activity collection and validation model. It summarized traditional state-of-the-art data fusion techniques from three plane domains in the 3D dynamic IoT model: devices, persons and timeline. The paper goes on to identify some new research trends and challenges of data fusion techniques in the IoT enabled PARM studies, and discusses some key enabling techniques for tackling them.
- Published
- 2020
12. Kalja valmistamisel käärimis-hapendamisprotsesside parameetrite jälgimine
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Taimalu, Sven Sören and Pisponen, Anna
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pärm ,piimhappebakterid ,bakalaureusetööd ,käärimine ,sidrunhape ,kali ,Brix - Abstract
Bakalaureusetöö Toiduainete tehnoloogia õppekaval Kali on enamasti pärmi toimel kääritatud jook, kuid varasemalt kasutati protsessis ka piimhappebaktereid (LAB). Käesoleva töö esmärk on selgitada välja, kuidas piimhappebakterid mõjutavad nii üksi kui ka koos pärmiga kaljavirde käärimist 16 tunni käärimise jooksul. Töös tehti selgeks üldine kalja tootmistehnoloogia ning võimalused tootmiseks. Vaadeldi teiste autorite tulemusi seoses kalja või pärmide/piimhappebakterite uurimisega. Valiti LAB-kultuurid: Nordwise Lactobacillus plantarum TAK69, Wildbrew Sour Pitch L. plantarum, Wildbrew Helveticus Pitch L. helveticus. Töös leiti, et happeliseim oli Sour Pitch, järgnes Helveticus Pitch ning viimaseks Nordwise. Koos pärmiga käärimisel oli suurim happesus (g/L sidrunhapet) enamasti 80/20 vahekorras LAB-pärm käärimisega ning enim sidrunhapet leidus Sour Pitchiga (2,84 g/L), veidi vähem Helveticus Pitch-iga (2,24 g/L) ning Nordwise puhul oli suurim happesus 50/50 puhul, 80/20 happesus sel puhul 1,45 g/L. 50/50 vahekorraga oli madalaim suhkrusisaldus, kuid võrreldes 80/20 vahekorraga Sour Pitch ja Helveticus Pitch puhul veidi kõrgem pH ja madalam sidrunhappe sisaldus: Sour Pitch 2,58 g/L; Helveticus Pitch 2,09 g/L; Nordwise 1,62 g/L. 100% LAB-iga käärimisel suhkrusisalduse näitaja ei langenud, pH oli kõrgeim ja sidrunhappe sisaldus madalaim, välja arvatud Sour Pitchiga, kus pH oli madalaim (3,57), kuid sidrunhappe sisaldus samuti madalaim (2,34 g/L). Poekalja pH-ga (3,45) võrreldes oli saadud kaljade pH kõrgem ning sidrunhappe sisaldus (poekaljal 1,15 g/L) samuti kõrgem. Tulemustest leidus, et kalja füüsikalis-keemilised näitajad olenevad enim kasutatavast LAB-kultuurist, väiksemal määral LAB-pärm vahekorrast juhul kui kasutati nii pärmi kui LAB-i. Ainult LAB-i kasutades oli käärimise kiirus väga aeglane ning näitajad muutusid väiksemal määral, välja arvatud Sour Pitch. Edasised uuringud ja katsed piimhappebakteritega võimaldaksid leida optimaalsed LAB-kultuurid ning meetodid hapendatud kalja tootmiseks. Kvass is a drink usually fermented with yeast but in the past lactic acid bacteria (LAB) have also been used. The purpose of this research is to monitor how LAB affect the fermentation process of kvass with or without the presence of yeast during 16 hours of fermentation. Technology and methods for kvass production were studied, along with prior research of kvass production and use of yeasts/LAB from authors. Three LABcultures were chosen: Nordwise Lactobacillus plantarum TAK69, Wildbrew Sour Pitch L. plantarum and Wildbrew Helveticus Pitch L. helveticus. In the study, Sour Pitch made for the most acidic kvass, followed by Helveticus Pitch and Nordwise was the least acidic. With the addition of yeast in fermentation, the greatest acidity (g/L citric acid) was found mostly with 80/20 proportion of LAB/yeast and the most citric acid was found with Sour Pitch (2,84 g/L), followed by Helveticus Pitch (2,24 g/L), for Nordwise, 50/50 had the highest acidity, 80/20 citric acid value was 1,45 g/L. The 50/50 proportion had the lowest sugar content but compared to 80/20, in the case of Sour Pitch and Helveticus Pitch, the pH was higher and acidity lower: Sour Pitch 2,58 g/L; Helveticus Pitch 2,09 g/L; Nordwise 1,62 g/L. In the case of 100% LAB fermentation, sugar content did not decrease, pH was the highest and acidity the lowest, except for Sour Pitch, which had the lowest pH (3,57) but also the lowest citric acid content (2,34 g/L). Compared to the pH of commercial kvass (3,45), kvass made in this research hag higher pH and also higher citric acid content (for commercial kvass 1,15 g/L). The results show, that physical-chemical indicators of kvass are most affected by the choice of LAB-cultures, less so by LAB-yeast proportions if yeast is used. When using only LAB, the speed of fermentation was slow and the indicators varied less, except for Sour Pitch. Further research and experiments with lactic acid bacteria could yield optimal LAB-cultures to use in production of acidified kvass.
- Published
- 2022
13. Novel actin filaments from Bacillus thuringiensis form nanotubules for plasmid DNA segregation.
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Shimin Jiang, Narita, Akihiro, Popp, David, Ghoshdastider, Umesh, Lin Jie Lee, Srinivasan, Ramanujam, Balasubramanian, Mohan K., Toshiro Oda, Koh, Fujiet, Larsson, Mårten, and Robinson, Robert C.
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ACTIN , *BACILLUS thuringiensis , *DNA , *ACTOMYOSIN , *PROTEINS - Abstract
Here we report the discovery of a bacterial DNA-segregating actinlike protein (BtParM) from Bacillus thuringiensis, which forms novel antiparallel, two-stranded, supercoiled, nonpolar helical filaments, as determined by electronmicroscopy. The BtParMfilament features of supercoiling and forming antiparallel double-strands are unique within the actin fold superfamily, and entirely different to the straight, double-stranded, polar helical filaments of all other known ParMs and of eukaryotic F-actin. The BtParM polymers show dynamic assembly and subsequent disassembly in the presence of ATP. BtParR, the DNA-BtParM linking protein, stimulated ATP hydrolysis/phosphate release by BtParM and paired two supercoiled BtParM filaments to form a cylinder, comprised of four strands with inner and outer diameters of 57 Å and 145 Å, respectively. Thus, in this prokaryote, the actin fold has evolved to produce a filament system with comparable features to the eukaryotic chromosomesegregating microtubule. [ABSTRACT FROM AUTHOR]
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- 2016
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14. Updating contextualized clinical practice guidelines on stroke rehabilitation and low back pain management using a novel assessment framework that standardizes decisions.
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Gambito, Ephraim D. V., Gonzalez‑Suarez, Consuelo B., Grimmer, Karen A., Valdecañas, Carolina M., Dizon, Janine Margarita R., Beredo, Ma. Eulalia J., and Zamora, Marcelle Theresa G.
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STROKE , *MEDICAL rehabilitation , *FILIPINOS , *MEDICAL care , *TWENTY-first century , *HEALTH , *SOCIAL history - Abstract
Background: Clinical practice guidelines need to be regularly updated with current literature in order to remain relevant. This paper reports on the approach taken by the Philippine Academy of Rehabilitation Medicine (PARM). This dovetails with its writing guide, which underpinned its foundational work in contextualizing guidelines for stroke and low back pain (LBP) in 2011. Methods: Working groups of Filipino rehabilitation physicians and allied health practitioners met to reconsider and modify, where indicated, the 'typical' Filipino patient care pathways established in the foundation guidelines. New clinical guidelines on stroke and low back pain which had been published internationally in the last 3 years were identified using a search of electronic databases. The methodological quality of each guideline was assessed using the iCAHE Guideline Quality Checklist, and only those guidelines which provided full text references, evidence hierarchy and quality appraisal of the included literature, were included in the PARM update. Each of the PARM-endorsed recommendations was then reviewed, in light of new literature presented in the included clinical guidelines. A novel standard updating approach was developed based on the criteria reported by Johnston et al. (Int J Technol Assess Health Care 19(4):646-655, 2003) and then modified to incorporate wording from the foundational PARM writing guide. The new updating tool was debated, pilot-tested and agreed upon by the PARM working groups, before being applied to the guideline updating process. Results: Ten new guidelines on stroke and eleven for low back pain were identified. Guideline quality scores were moderate to good, however not all guidelines comprehensively linked the evidence body underpinning recommendations with the literature. Consequently only five stroke and four low back pain guidelines were included. The modified PARM updating guide was applied by all working groups to ensure standardization of the wording of updated recommendations and the underpinning evidence bases. Conclusions: The updating tool provides a simple, standard and novel approach that incorporates evidence hierarchy and quality, and wordings of recommendations. It could be used efficiently by other guideline updaters particularly in developing countries, where resources for guideline development and updates are limited. When many people are involved in guideline writing, there is always the possibility of 'slippage' in use of wording and interpretation of evidence. The PARM updating tool provides a mechanism for maintaining a standard process for guideline updating processes that can be followed by clinicians with basic training in evidence-based practice principles. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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15. Plasmid partitioning systems of conjugative plasmids from Clostridium perfringens.
- Author
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Adams, Vicki, Watts, Thomas D., Bulach, Dieter M., Lyras, Dena, and Rood, Julian I.
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PLASMIDS , *CLOSTRIDIUM perfringens , *PATHOGENIC bacteria , *ANTIBIOTICS , *DRUG resistance in bacteria - Abstract
Many pathogenic strains of Clostridium perfringens carry several highly similar toxin or antibiotic resistance plasmids that have 35 to 40 kb of very closely related syntenous sequences, including regions that carry the genes encoding conjugative transfer, plasmid replication and plasmid maintenance functions. Key questions are how are these closely related plasmids stably maintained in the same cell and what is the basis for plasmid incompatibility in C. perfringens . Comparative analysis of the Rep proteins encoded by these plasmids suggested that this protein was not the basis for plasmid incompatibility since plasmids carried in a single strain often encoded an almost identical Rep protein. These plasmids all carried a similar, but not identical, parMRC plasmid partitioning locus. Phylogenetic analysis of the deduced ParM proteins revealed that these proteins could be divided into ten separate groups. Importantly, in every strain that carried more than one of these plasmids, the respective ParM proteins were from different phylogenetic groups. Similar observations were made from the analysis of phylogenetic trees of the ParR proteins and the parC loci. These findings provide evidence that the basis for plasmid incompatibility in the conjugative toxin and resistance plasmid family from C. perfringens resides in subtle differences in the parMRC plasmid partitioning loci carried by these plasmids. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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16. Fermenteri tööpõhimõte ja kasutusvõimalused mikrobioloogias
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Sahharov, Pavel, Andreson, Helena, and Abel, Maarja
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pärm ,bakalaureusetööd ,segamiskiirus ,kasutusjuhend ,Applikon my-Control - Abstract
Bakalaureusetöö Toiduainete tehnoloogia õppekaval Fermentereid ehk bioreaktoreid kasutatakse laialdaselt erinevates valdkondades, sealhulgas näiteks teaduslaborites mitmesuguste mikrobioloogiliste protsesside uurimiseks. Ka Eesti Maaülikooli Toiduteaduse ja toiduainete tehnoloogia õppetooli mikrobioloogia laboris on Applikon my-Control 2 L mahutavusega fermenter, millel seni puudus varasem kasutuskogemus, kuid mis omab suurt potentsiaali erinevateks rakendusteks nii mikrobioloogias kui ka toiduteaduses laiemalt. Bakalaureusetöö eesmärk on anda põhjalik ülevaade fermenterite tööpõhimõtetest, kasutusaladest ning eksperimentaalse töö alusel koostada Applikon my-Control fermenteri kasutusjuhend. Eksperimentaalse töö jaoks kasutati fermenteri riist- ja tarkvara kahe pärmikultuuri kasvatamisel, et jälgida fermentatsiooniprotsessi kulgu ja hinnata seadme töö stabiilsust. Eksperimentaalses osas jälgiti fermenteri erinevate seguri kiiruste (100-300 rpm) mõju pärmiliikide Saccharomyces pastorianus ja Saccharomyces bayanus rakkude arvule, kaalule ja kasvusöötme pH väärtusele fermentatsiooniprotsessi käigus. Leiti, et S. pastorianus’e kasvatamiseks sobisid kõik valitud segamiskiirused 100-300 rpm, kuid suurim pärmirakkude arvu muutus registreeriti segamiskiiruse 200 rpm kasutamisel (10,58 ± 0,08 log rakku/L). S. bayanus’e rakkude arvu määramine biomassi anduriga ebaõnnestus pärmi poolt moodustatud biokile tõttu, aga kaalu muutuse põhjal järeldati, et S. bayanus’e kasv toimus samuti kõige aktiivsemalt segamiskiiruse 200 rpm juures. Mõlema pärmi fermentatsiooniprotsessi käigus toimus esialgu kasvusöötme pH langus ning hiljem selle tõus. S. pastorianus kultuuri kasutamisel langes pH kuni 40. tunnini, aga S. bayanus’e fermentatsiooniprotsessi käigus langes pH minimaalseima väärtuseni juba 16 tundi pärast pärmi söötmesse lisamist. S. bayanus’e pH väärtuse muutused olid prominentsemad segamiskiiruse 300 rpm juures. Eksperimentide käigus saadud tulemused tõestasid Applikon my-Control seadme töö stabiilsust. Lisaks koostati katsete läbiviimise käigus Applikon my-Control 2 L fermenteri detailne kasutusjuhend, mis hõlbustab seadme edaspidist kasutamist erinevate katsete läbiviimisel. Fermenters, also known as bioreactors, are widely used in various fields, such as, e.g., research laboratories to investigate various microbiological processes. The laboratory of the Chair of Food Science and Technology of the Estonian University of Life Sciences has a new Applikon my-Control fermenter, have so far not had any user-experience by stuff, but has great potential for various applications in microbiology and food science in general. The aim of this Bachelor's thesis is to provide a thorough overview of the operating principles and applications of fermenters in general and to compile the operating manual for the Applikon my-Control fermenter based on the experiments. For experimental work, current fermenter hardware and software technologies were used to grow two types of yeast, monitor the progress of the fermentation process and assess the stability of the equipment. In the experimental part, the effect of different stirrer agitation speeds (100-300 rpm) on the number of cells of Saccharomyces pastorianus and Saccharomyces bayanus, their weight and the overall pH of the growth medium were evaluated during the fermentation process. Stirring speeds of 100-300 rpm were found to be suitable for growing S. pastorianus, but the largest change in the number of yeast cells was recorded at a stirring speed of 200 rpm (10.58 ± 0.08 log cells/L). S. bayanus cell counting with the biomass sensor failed, however, due to its biofilm forming ability, but based on the changes in weight, it was determined that S. bayanus growth was also most active at a stirring speed of 200 rpm. During the fermentation process of both types of yeast, the pH of the growth medium initially decreased and later increased. During S. pastorianus growth, the pH was decreasing until the 40-hour mark, but during the fermentation process of S. bayanus, the pH dropped to a minimum as early as 16 hours after the addition of the yeast to the medium. Changes in the pH of S. bayanus were more prominent at an increased stirring speed of 300 rpm. The results of the experiments showed the stability of the Applikon my-Control. In addition, a detailed user manual for the Applikon my-Control was compiled in order for the device to be used for various continual tests.
- Published
- 2021
17. Development of the Parental Modelling of Eating Behaviours Scale ( PARM): links with food intake among children and their mothers.
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Palfreyman, Zoe, Haycraft, Emma, and Meyer, Caroline
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STATISTICAL correlation , *EXPERIMENTAL design , *FACTOR analysis , *FOOD habits , *INGESTION , *RESEARCH methodology , *MOTHERS , *QUESTIONNAIRES , *RESEARCH funding , *SCALE analysis (Psychology) , *SELF-evaluation , *STATISTICS , *SAMPLE size (Statistics) , *DATA analysis , *BODY mass index , *RESEARCH methodology evaluation , *DESCRIPTIVE statistics ,RESEARCH evaluation - Abstract
This study aimed to develop a self-report questionnaire to explore parental modelling of eating behaviours and then to use the newly developed measure to investigate associations between parental modelling with healthy and unhealthy food intake in both mothers and their children. Mothers ( n = 484) with a child aged between 18 months and 8 years completed the Parental Modelling of Eating Behaviours Scale ( PARM), a new, self-report measure of modelling, as well as a food frequency questionnaire. Principal components analysis of the PARM identified 15 items grouped into three subscales: verbal modelling (modelling through verbal communication); unintentional modelling ( UM) (children adopting eating behaviours that parents had not actively modelled); and behavioural consequences (children's eating behaviours directly associated with parental modelling). The PARM subscales were found to be differentially related to food intake. Maternally perceived consequences of behavioural modelling were related to increased fruit and vegetable intake in both mothers and children. UM was related to higher levels of savoury snack intake in both mothers and their children. This study has highlighted three distinct aspects of parental modelling of eating behaviours. The findings suggest that mothers may intentionally model healthy food intake while unintentionally acting as role models for their children's less healthy, snack food intake. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
18. O projeto Museu de Ferro & da Região de Moncorvo: entre a utopia e a realidade (possível).
- Author
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CAMPOS, Nelson
- Subjects
- *
MUSEUMS , *PUBLIC institutions , *PRESERVATION of cultural property , *MUSEUM studies , *MUSEUM techniques - Abstract
A brief history of the creation of a local museum in a former mining area; highlights the role of a local association for the protection of heritage (PARM) in his recovery and in museological idealization; having adopted a management model of partnership with the local government, it is the balance between what was possible and the constraints encountered. [ABSTRACT FROM AUTHOR]
- Published
- 2014
19. Naatrium- ja kaaliumsoolade stressi kvantitatiivne analüüs pärmides
- Author
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Illarionov, Aleksandr, Kumar, Rahul, and Lahtvee, Petri-Jaan
- Subjects
mittekonventsionaalne pärm ,Rhodosporidium toruloides ,non-conventional yeast ,Saccharomyces cerevisiae ,yeast ,osmootiline stress ,pärm ,image analysis ,Kluyveromyces marxianus ,biotehnoloogia ,osmotic stress ,soola stress ,pilditöötlus ,salt stress ,biotechnology - Abstract
Saline stress is commonly encountered by microbial cell factories. The molecular mechanisms of saline stress are identified in the conventional budding yeast Saccharomyces cerevisiae that is used in biotechnology. However, for diversification of microbial cell factories, non-conventional yeasts provide an attractive opportunity but saline stress in these yeasts is not very well investigated. This thesis is focused on achieving foundational understanding of morphological and physiological response to saline stress of conventional and non-conventional yeasts by comparing Saccharomyces cerevisiae W303 and CEN.PK113-7D together with Kluyveromyces marxianus and Rhodotorula toruloides. The results showed that effects of Na+ stress could be ameliorated by potassium supplementation in S. cerevisiae CEN.PK113-7D increasing its specific growth rate by almost four-fold. In addition, combination of sodium and potassium salts resulted in impaired acetic acid and/or ethanol metabolism in S. cerevisiae. Further, in this thesis, a neural network-based image analysis software pipeline for a quantitative evaluation of saline stress response was developed that could be used to determine differences in cell volume among the strains. Quantitative image analysis found a high variability in cell volume dynamics implying distinct stress response mechanisms among different yeasts. The cell volume differences could be used to model saline stress responses in various bioprocesses in biotechnology. In estonian: Kõrgete soola kontsenteratsioonide poolt põhjustatud osmootne stress on levinud stressifaktor tööstuslikult kasutavatele mikroorganismidel põhinevatele rakuvabrikutele. Soola stressi molekulaarsed mehhanismid on tuvastatud tavapärases punguvas pärmis Saccharomyces cerevisiae, mida kasutatakse biotehnoloogias. Mittekonventsionaalsed pärmid kujundavad endast atraktiivset võimalust mikrobioloogiliste rakuvabrikute diversifitseerimiseks, kuid soola stress sellistes pärmides on tänini praktiliselt kirjeldamata. Käesoleva bakalaureusetöö eesmärk on fundamentaalse arusaama saavutamine konventsionaalsete ja mittekonventsionaalsete pärmide ja nende soola stressi morfoloogilise ja füsioloogilise vastuste suhtes. Võrdluseks on kasutatud Saccharomyces cerevisiae CEN.PK113-7D ja W303, Kluyveromyces marxianus ja Rhodotorula toruloides pärmide tüvesid. Tulemused näidavad, et naatriumi tingitud stressi effektid võib leevendada kaaliumi lisamisega pärmis S. cerevisiae CEN.PK113-7D, peaaegu neljakordistades tema erikasvukiirust. Lisaks, naatriumi ja naatriumi/kaaliumi kombinatsioonid põhjustasid nõrgenenud atsetaadi ja/või etanooli metabolismi pärmis S. cerevisiae. Peale selle, tehisnärvivõrgul põhinev pilditöötluse tarkvara oli välja töötatud soola stressist põhjustatud rakkude ruumala muutuste kvantitatiivseks analüüsiks. Kvantitatiivne piltide analüüs on leidnud suurt variatiivsust rakkude mahus, vihjates eristuvatele stressile vastuste mehhanismidele erinevates pärmides. Rakkude mahu erinevusi võib kasutada soola stressile vastuste modelleerimiseks mitmesugustes biotehnoloogia bioprotsessides.
- Published
- 2020
20. Are prophylactic anti-reflux medications effective after esophageal atresia repair? Systematic review and meta-analysis
- Author
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Alison Hock, Yuhki Koike, Yong Chen, Hiromu Miyake, Agostino Pierro, and Shogo Seo
- Subjects
medicine.medical_specialty ,medicine.drug_class ,MEDLINE ,Proton-pump inhibitor ,Review Article ,Proton pump inhibitor ,Global Health ,03 medical and health sciences ,Postoperative Complications ,H2 blocker ,0302 clinical medicine ,030225 pediatrics ,Internal medicine ,Pediatric surgery ,Humans ,Medicine ,030212 general & internal medicine ,Child ,Prospective cohort study ,Esophageal stricture ,business.industry ,Incidence ,ParM ,Proton Pump Inhibitors ,General Medicine ,medicine.disease ,3. Good health ,Gastroesophageal reflux ,Esophagoplasty ,Atresia ,Meta-analysis ,Esophageal atresia ,Pediatrics, Perinatology and Child Health ,Surgery ,business ,Anti-reflux medicine - Abstract
Purpose Gastroesophageal reflux after surgical repair of esophageal atresia (EA) can be associated with complications, such as esophageal stricture. Recent guidelines recommend prophylactic anti-reflux medication (PARM) after EA repair. However, the effectiveness of PARM is still unclear. The aim of this study was to review evidence surrounding the use of PARM in children operated for EA. Methods We performed a systematic review and meta-analysis. We searched Medline, EMBASE, and the Cochrane Databases from inception until the end of 2016 for comparative studies of PARM versus no PARM (control). Primary outcome was postoperative esophageal stricture. Quality of evidence was assessed using GRADE system. Results We identified four observational studies that focused on esophageal stricture as an outcome. A total of 362 patients were included in meta-analysis. There was no significant difference in esophageal stricture rates between PARM and control (OR = 1.14; 95% CI = 0.61–2.13; p = 0.68; I2 = 38%). The quality of the evidence was very low, due to lack of precision as a consequence of small study sizes. Conclusions Our results indicate that PARM does not reduce the incidence of esophageal stricture after EA repair. Future well-controlled prospective studies are needed to obtain higher quality evidence.
- Published
- 2018
21. The assembly dynamics of a divergent member of the ParM actin-like protein family
- Author
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Rivera, Christopher Richard
- Subjects
Biochemistry ,actin ,assembly kinetics ,ParM ,Partitioning operon - Abstract
The ParM protein, encoded by the parMRC locus from plasmid R1, is the best-characterized actin homolog present in prokaryotes. In conjunction with a nucleoprotein complex formed by a DNA binding protein ParR and a DNA centromere parC, ParM constructs a simple mitotic spindle that pushes plasmid DNA to opposite poles of a bacterial cell for DNA segregation. Like actin, ParM assembles into ATP-dependent double-stranded, helical filaments via a nucleation condensation reaction. However, unlike actin, it displays three kinetic properties that are essential to its function: rapid spontaneous nucleation, bilateral elongation and ATPase dependent dynamic instability: the stochastic switching between filament elongation and rapid catastrophic shrinkage. In this dissertation, we investigated three questions related to ParM's evolution and function. First, many divergent R1 ParM homologs are encoded by other plasmids, and function in plasmid DNA segregation. We asked whether the filament architecture and assembly dynamics are conserved in a divergent member of the ParM family, the ParM protein from plasmid pB171. Using microscopic and biophysical techniques, we compared and contrasted the architecture and assembly of these related proteins. Despite being only 41% identical, we find that R1 and pB171 ParM polymerize into nearly identical filaments that display similar assembly dynamics, suggesting that structure and function are conserved in the ParM family. Second, we asked whether ParM prefers ATP or GTP in vitro. Using biochemical assays and TIRF microscopy, we find that ParM displays similar polymerization kinetics and stability in the presence of either nucleotide, but binds to ATP ten times tighter than GTP. Third, the structural basis for ParM filament dynamic instability remains poorly understood. Using cryo-electron microscopy to evaluate ParM filaments, we find that the nucleotide binding pocket of ParM protomers exist in an open or closed state, and that ATP hydrolysis shifts the distribution of protomers states; these findings suggest a mechanism for dynamic instability.
- Published
- 2011
22. Contextualizing Western guidelines for stroke and low back pain to a developing country (Philippines): an innovative approach to putting evidence into practice efficiently.
- Author
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Gonzalez-Suarez, Consuelo B., Grimmer-Somers, Karen, Margarita Dizon, Janine, King, Ellena, Lorenzo, Sylvan, Valdecanas, Carolina, Gambito, Ephraim, and Fidel, Belinda
- Subjects
STROKE ,BACKACHE ,MEDICAL decision making ,MEDICAL care - Abstract
Background: High-quality evidence-based clinical guidelines are widely available for many diseases. Clinical guidelines support evidence-based care decisions and improved health outcomes. Most clinical practice guidelines have been developed in the Western world and reflect a developed country's health systems and services, disease epidemiology, and workforce. Such guidelines are therefore not immediately relevant or generalizable to developing countries. Guidelines are expensive to produce, and it is more resource efficient for developing countries to contextualize available Western guidelines, rather than develop their own. This paper describes a leadership initiative by the Philippines Association of Rehabilitation Medicine to contextualize high-quality relevant Western guidelines for local management of stroke and low back pain. Methods: Twenty-one steps were developed, covering initial training and establishing the framework within which recommendations were contextualized; then guideline searching, critiquing, and including; and then contextualization, review, and implementation. A writing guide assisted the group to endorse recommendations in a standard manner, relevant to a "typical" patient journey, and to contextualize recommendations for local settings. Results: Recommendations were extracted from eight low back pain and five stroke clinical guidelines. Philippines Association of Rehabilitation Medicine endorsements were made, reflecting summarized recommendations and underpinning strength of the evidence body. Philippines Association of Rehabilitation Medicine context points contextualized the recommendations in terms of local health service delivery. Conclusion: A systematic reproducible process was applied to contextualize high-quality, relevant Western guidelines for immediate application to one developing country. This approach focused resources on contextualization, implementation, and uptake rather than de novo development. This leadership initiative offers a resource efficient way to implement evidence-based practice in developing countries when there is neither time nor resources for de novo guideline development. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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23. In vitro Reconstitution of DNA Segregation; A Plasmid Spindle Driven by a Dynamically Unstable Actin Homologue
- Author
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Garner, Ethan Clark
- Subjects
Biology, Cell ,Biophysics, General ,Biology, Microbiology ,ParM ,Dynamic Instability ,plasmid segregation ,cytoskelton - Abstract
The par operon of the R1 plasmid constructs a DNA segregating spindle from three components, parC, ParR, and ParM. parC is a centromeric stretch of DNA which is bound by the protein ParR. ParM is an actin homologue that polymerizes into two stranded filaments that can interact with the ParR/parC complex. These three components are both necessary and sufficient to segregate parC containing plasmids, implying that the par operon is a biochemically self-contained DNA segregation apparatus. To elucidate how this system functions to segregate plasmid DNA, we wished to determine the intrinsic kinetic properties of ParM assembly, and how this assembly is regulated by the interaction with its cargo, the ParR/parC complex.We find that ParM displays three properties that distinguish its assembly from that of eukaryotic actins. 1) ParM displays hydrolysis dependent dynamic instability, the stochastic switching between states of growth and rapid depolymerization. 2) ParM filaments display a very rapid rate of nucleation, occurring at a rate 200-fold faster than actin. 3) ParM filaments exhibit no kinetic polarity, with equal rates of growth at each filament end.By combining ParM with bead immobilized ParR/parC we demonstrate that these three components can create bipolar spindles in vitro similar to those observed in vivo. ParR/parC coated microspheres are connected by bundles of ParM filaments that elongate over time, pushing the microspheres apart over long distances. Speckle microscopy and photobleaching experiments demonstrate that this motility is driven by insertional polymerization at the bead surface. We find that the ParR/parC complex prevents ParM filament ends from catastrophe by stabilizing filaments down to the ATP-ParM critical concentration. Futhermore, we show that the dynamic instability of ParM is critical to the spatial regulation of the R1 spindle, as filament ends that are not bound at each end by ParR/parC are destined to undergo catastrophe. The dynamic instability of ParM also provides an energetic differential to power spindle elongation, as the turnover of background, unbound filaments provide the monomer excess required for the growth of stabilized, spindle associated filaments.
- Published
- 2007
24. The Bacterial Cytoskeleton.
- Author
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Cabeen, Matthew T. and Jacobs-Wagner, Christine
- Subjects
- *
BACTERIA , *CYTOSKELETON , *CYTOSKELETAL proteins , *CYTOPLASM , *CELL division , *CELL motility - Abstract
Bacteria, like eukaryotes, employ cytoskeletal elements to perform many functions, including cell morphogenesis, cell division, DNA partitioning, and cell motility. They not only possess counterparts of eukaryotic actin, tubulin, and intermediate filament proteins, but they also have cytoskeletal elements of their own. Unlike the rigid sequence and structural conservation often observed for eukaryotic cytoskeletal proteins, the bacterial counterparts can display considerable diversity in sequence and function across species. Their wide range of function highlights the flexibility of core cytoskeletal protein motifs, such that one type of cytoskeletal element can perform various functions, and one function can be performed by different types of cytoskeletal elements. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
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25. Plasmid segregation: how to survive as an extra piece of DNA.
- Author
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Salje, Jeanne
- Subjects
- *
PLASMIDS , *CELL cycle , *DNA-binding proteins , *MOLECULAR biology - Abstract
Non-essential extra-chromosomal DNA elements such as plasmids are responsible for their own propagation in dividing host cells, and one means to ensure this is to carry a miniature active segregation system reminiscent of the mitotic spindle. Plasmids that are maintained at low numbers in prokaryotic cells have developed a range of such active partitioning systems, which are characterized by an impressive simplicity and efficiency and which are united by the use of dynamic, nucleotide-driven filaments to separate and position DNA molecules. A comparison of different plasmid segregation systems reveals (i) how unrelated filament-forming and DNA-binding proteins have been adopted and modified to create a range of simple DNA segregating complexes and (ii) how subtle changes in the few components of these DNA segregation machines has led to a remarkable diversity in the molecular mechanisms of closely related segregation systems. Here, our current understanding of plasmid segregation systems is reviewed and compared with other DNA segregation systems, and this is extended by a discussion of basic principles of plasmid segregation systems, evolutionary implications and the relationship between an autonomous DNA element and its host cell. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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26. Molecular mechanism of bundle formation by the bacterial actin ParM
- Author
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Popp, David, Narita, Akihiro, Iwasa, Mitsusada, Maéda, Yuichiro, and Robinson, Robert C.
- Subjects
- *
ACTIN , *DNA , *NUCLEIC acid separation , *BACTERIAL cell walls , *MOLECULAR dynamics , *CELL division , *ELECTRON microscopy , *PLASMIDS , *CELLULOSE , *POLYVINYL alcohol - Abstract
Abstract: The actin homolog ParM plays a microtubule-like role in segregating DNA prior to bacterial cell division. Fluorescence and cryo-electron microscopy have shown that ParM forms filament bundles between separating DNA plasmids in vivo. Given the lack of ParM bundling proteins it remains unknown how ParM bundles form at the molecular level. Here we show using time-lapse TIRF microscopy, under in vitro molecular crowding conditions, that ParM-bundle formation consists of two distinct phases. At the onset of polymerization bundle thickness and shape are determined in the form of nuclei of short helically disordered filaments arranged in a liquid-like lattice. These nuclei then undergo an elongation phase whereby they rapidly increase in length. At steady state, ParM bundles fuse into one single large aggregate. This behavior had been predicted by theory but has not been observed for any other cytomotive biopolymer, including F-actin. We employed electron micrographs of ParM rafts, which are 2-D analogs of 3-D bundles, to identify the main molecular interfilament contacts within these suprastructures. The interface between filaments is similar for both parallel and anti-parallel orientations and the distribution of filament polarity is random within a bundle. We suggest that the interfilament interactions are not due to the interactions of specific residues but rather to long-range, counter ion mediated, electrostatic attractive forces. A randomly oriented bundle ensures that the assembly is rigid and that DNA may be captured with equal efficiency at both ends of the bundle via the ParR binding protein. [Copyright &y& Elsevier]
- Published
- 2010
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27. Evolution of cytomotive filaments: The cytoskeleton from prokaryotes to eukaryotes
- Author
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Löwe, Jan and Amos, Linda A.
- Subjects
- *
BIOLOGICAL evolution , *CYTOSKELETON , *EUKARYOTIC cells , *PROKARYOTES , *TUBULINS , *PLASMIDS - Abstract
Abstract: The basic features of the active filaments that use nucleotide hydrolysis to organise the cytoplasm are remarkably similar in the majority of all cells and are either actin-like or tubulin-like. Nearly all prokaryotic cells contain at least one form of FtsZ, the prokaryotic homologue of tubulin and some bacterial plasmids use tubulin-like TubZ for segregation. The other main family of active filaments, assembled from actin-like proteins, occurs in a wide range of bacterial species as well as in all eukaryotes. Some bacterial plasmids also use ParM, another actin-like protein. Higher-order filament structures vary from simple to complex depending on the cellular application. Equally, filament-associated proteins vary greatly between species and it is not possible currently to trace their evolution from prokaryotes to eukaryotes. This lack of similarity except in the three-dimensional structures and longitudinal interactions between the filament subunits hints that the most basic cellular function of the filaments is to act as linear motors driven by assembly dynamics and/or bending and hence we term these filament systems ‘cytomotive’. The principle of cytomotive filaments seems to have been invented independently for actin- and tubulin-like proteins. Prokaryotes appear to have a third class of cytomotive filaments, typically associated with surfaces such as membranes or DNA: Walker A cytoskeletal ATPases (WACA). A possible evolutionary relationship of WACAs with eukaryotic septins is discussed. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
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28. Bacterial actin: architecture of the ParMRC plasmid DNA partitioning complex.
- Author
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Salje, Jeanne and Löwe, Jan
- Subjects
- *
ACTIN , *POLYMERIZATION , *PLASMIDS , *DNA-binding proteins , *PROKARYOTES , *ELECTRON microscopy , *OLIGOMERS - Abstract
The R1 plasmid employs ATP-driven polymerisation of the actin-like protein ParM to move newly replicated DNA to opposite poles of a bacterial cell. This process is essential for ensuring accurate segregation of the low-copy number plasmid and is the best characterised example of DNA partitioning in prokaryotes. In vivo, ParM only forms long filaments when capped at both ends by attachment to a centromere-like region parC, through a small DNA-binding protein ParR. Here, we present biochemical and electron microscopy data leading to a model for the mechanism by which ParR–parC complexes bind and stabilise elongating ParM filaments. We propose that the open ring formed by oligomeric ParR dimers with parC DNA wrapped around acts as a rigid clamp, which holds the end of elongating ParM filaments while allowing entry of new ATP-bound monomers. We propose a processive mechanism by which cycles of ATP hydrolysis in polymerising ParM drives movement of ParR-bound parC DNA. Importantly, our model predicts that each pair of plasmids will be driven apart in the cell by just a single double helical ParM filament. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
29. Molecular structure of the ParM polymer and the mechanism leading to its nucleotide-driven dynamic instability.
- Author
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Popp, David, Narita, Akihiro, Oda, Toshiro, Fujisawa, Tetsuro, Matsuo, Hiroshi, Nitanai, Yasushi, Iwasa, Mitsusada, Maeda, Kayo, Onishi, Hirofumi, and Ma&;#x00E9;da, Yuichiro
- Subjects
- *
MOLECULAR structure , *GUANOSINE triphosphatase , *EUKARYOTIC cells , *MOLECULAR biology , *BACTERIAL cell walls - Abstract
ParM is a prokaryotic actin homologue, which ensures even plasmid segregation before bacterial cell division. In vivo, ParM forms a labile filament bundle that is reminiscent of the more complex spindle formed by microtubules partitioning chromosomes in eukaryotic cells. However, little is known about the underlying structural mechanism of DNA segregation by ParM filaments and the accompanying dynamic instability. Our biochemical, TIRF microscopy and high-pressure SAX observations indicate that polymerization and disintegration of ParM filaments is driven by GTP rather than ATP and that ParM acts as a GTP-driven molecular switch similar to a G protein. Image analysis of electron micrographs reveals that the ParM filament is a left-handed helix, opposed to the right-handed actin polymer. Nevertheless, the intersubunit contacts are similar to those of actin. Our atomic model of the ParM-GMPPNP filament, which also fits well to X-ray fibre diffraction patterns from oriented gels, can explain why after nucleotide release, large conformational changes of the protomer lead to a breakage of intra- and interstrand interactions, and thus to the observed disintegration of the ParM filament after DNA segregation. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
30. Concerning the dynamic instability of actin homolog ParM
- Author
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Popp, David, Yamamoto, Akihiro, Iwasa, Mitsusada, Narita, Akihiro, Maeda, Kayo, and Maéda, Yuichiro
- Subjects
- *
CHEMICAL reactions , *ELECTRON microscopy , *MICROTUBULES , *POLYMERIZATION - Abstract
Abstract: Using in vitro TIRF- and electron-microscopy, we reinvestigated the dynamics of native ParM, a prokaryotic DNA segregation protein and actin homolog. In contrast to a previous study, which used a cysteine ParM mutant, we find that the polymerization process of wild type ATP-ParM filaments consists of a polymerization phase and a subsequent steady state phase, which is dynamically unstable, like that of microtubules. We find that the apparent bidirectional polymerization of ParM, is not due to the intrinsic nature of this filament, but results from ParM forming randomly oriented bundles in the presence of crowding agents. Our results imply, that in the bacterium, ParM filaments spontaneously form bipolar bundles. Due to their intrinsic dynamic instability, ParM bundles can efficiently “search” the cytoplasmic lumen for DNA, bind it equally well at the bipolar ends and segregate it approximately symmetrically, by the insertion of ParM subunits at either end. [Copyright &y& Elsevier]
- Published
- 2007
- Full Text
- View/download PDF
31. Dynamic Filaments of the Bacterial Cytoskeleton.
- Author
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Michie, Katharine A. and Löwe, Jan
- Subjects
- *
CYTOPLASMIC filaments , *CYTOSKELETON , *PROTEINS , *CELLULAR control mechanisms , *BACTERIA - Abstract
Bacterial cells contain a variety of structural filamentous proteins necessary for the spatial regulation of cell shape, cell division, and chromosome segregation, analogous to the eukaryotic cytoskeletal proteins. The molecular mechanisms by which these proteins function are beginning to be revealed, and these proteins show numerous three-dimensional structural features and biochemical properties similar to those of eukaryotic actin and tubulin, revealing their evolutionary relationship. Recent technological advances have illuminated links between cell division and chromosome segregation, suggesting a higher complexity and organization of the bacterial cell than was previously thought. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
32. Crystal Structure of an Archaeal Actin Homolog
- Author
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Roeben, Annette, Kofler, Christine, Nagy, István, Nickell, Stephan, Ulrich Hartl, F., and Bracher, Andreas
- Subjects
- *
ACTIN , *ADENOSINE triphosphatase , *GENOMICS , *ARCHAEBACTERIA - Abstract
Prokaryotic homologs of the eukaryotic structural protein actin, such as MreB and ParM, have been implicated in determination of bacterial cell shape, and in the segregation of genomic and plasmid DNA. In contrast to these bacterial actin homologs, little is known about the archaeal counterparts. As a first step, we expressed a predicted actin homolog of the thermophilic archaeon Thermoplasma acidophilum, Ta0583, and determined its crystal structure at 2.1Å resolution. Ta0583 is expressed as a soluble protein in T.acidophilum and is an active ATPase at physiological temperature. In vitro, Ta0583 forms sheets with spacings resembling the crystal lattice, indicating an inherent propensity to form filamentous structures. The fold of Ta0583 contains the core structure of actin and clearly belongs to the actin/Hsp70 superfamily of ATPases. Ta0583 is approximately equidistant from actin and MreB on the structural level, and combines features from both eubacterial actin homologs, MreB and ParM. The structure of Ta0583 co-crystallized with ADP indicates that the nucleotide binds at the interface between the subdomains of Ta0583 in a manner similar to that of actin. However, the conformation of the nucleotide observed in complex with Ta0583 clearly differs from that in complex with actin, but closely resembles the conformation of ParM-bound nucleotide. On the basis of sequence and structural homology, we suggest that Ta0583 derives from a ParM-like actin homolog that was once encoded by a plasmid and was transferred into a common ancestor of Thermoplasma and Ferroplasma. Intriguingly, both genera are characterized by the lack of a cell wall, and therefore Ta0583 could have a function in cellular organization. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
33. Evidence that compatibility of closely related replicons in Clostridium perfringens depends on linkage to parMRC -like partitioning systems of different subfamilies
- Author
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Priscilla A. Johanesen, Vicki Adams, Dena Lyras, Thomas D. Watts, and Julian I. Rood
- Subjects
DNA Replication ,DNA Topoisomerase IV ,DNA, Bacterial ,0301 basic medicine ,Clostridium perfringens ,030106 microbiology ,Locus (genetics) ,Biology ,medicine.disease_cause ,03 medical and health sciences ,Clostridium ,Plasmid ,Bacterial Proteins ,medicine ,Replicon ,Molecular Biology ,Gene ,Peptide sequence ,Genetics ,Base Sequence ,ParM ,Drug Resistance, Microbial ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,Actins ,Anti-Bacterial Agents ,Repressor Proteins ,Genetic Loci ,Conjugation, Genetic ,Plasmids - Abstract
Clostridium perfringens produces an extensive repertoire of toxins and extracellular enzymes, many of which are intimately involved in the progression of disease and are encoded by genes on conjugative plasmids. In addition, many C. perfringens strains can carry up to five of these conjugative toxin or antimicrobial resistance plasmids, each of which has a similar 35kb backbone. This conserved backbone includes the tcp conjugation locus and the central control region (CCR), which encodes genes involved in plasmid regulation, replication and partitioning, including a parMRC partitioning locus. Most conjugative plasmids in C. perfringens have a conserved replication protein, raising questions as to how multiple, closely related plasmids are maintained within a single strain. Bioinformatics analysis has highlighted the presence of at least 10 different parMRC partitioning system families (parMRCA-J) in these plasmids, with differences in amino acid sequence identity between each ParM family ranging from 15% to 54%. No two plasmids that encode genes belonging to the same partitioning family have been observed in a single strain, suggesting that these families represent the basis for plasmid incompatibility. In an attempt to validate the proposed parMRC incompatibility groups, genetically marked C. perfringens plasmids encoding identical parMRCC or parMRCD homologues or different combinations of parMRCA, parMRCC and parMRCD family homologues were introduced into a single strain via conjugation. The stability of each plasmid was determined using an incompatibility assay in which the plasmid profile of each strain was monitored over the course of two days in the absence of direct selection. The results showed that plasmids with identical parMRCC or parMRCD homologues were incompatible and could not coexist in the absence of external selection. By contrast, plasmids that encoded different parMRC homologues were compatible and could coexist in the same cell in the absence of selection, with the exception of strains housing parMRCC and parMRCD combinations, which showed a minor incompatibility phenotype. In conclusion, we have provided the first direct evidence of plasmid incompatibility in Clostridium spp. and have shown experimentally that the compatibility of conjugative C. perfringens plasmids correlates with the presence of parMRC-like partitioning systems of different phylogenetic subfamilies.
- Published
- 2017
34. Plasmid Segregation Mechanisms.
- Author
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Ebersbach, Gitte and Gerdes, Kenn
- Subjects
- *
PLASMIDS , *CYTOPLASMIC inheritance , *ACTIN , *ACTOMYOSIN , *ADENOSINE triphosphatase - Abstract
Bacterial plasmids encode partitioning (par) loci that ensure ordered plasmid segregation prior to cell division. par loci come in two types: those that encode actin-like ATPases and those that encode deviant Walker-type ATPases. ParM, the actin-like ATPase of plasmid R1, forms dynamic filaments that segregate plasmids paired at mid-cell to daughter cells. Like microtubules, ParM filaments exhibit dynamic instability (i.e., catastrophic decay) whose regulation is an important component of the DNA segregation process. The Walker box ParA ATPases are related to MinD and form highly dynamic, oscillating filaments that are required for the subcellular movement and positioning of plasmids. The role of the observed ATPase oscillation is not yet understood. However, we propose a simple model that couples plasmid segregation to ParA oscillation. The model is consistent with the observed movement and localization patterns of plasmid foci and does not require the involvement of plasmid-specific host-encoded factors. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
35. Partial anhysteretic remanent magnetization (pARM) of synthetic single- and multi-domain magnetites and its paleoenvironmental significance.
- Author
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Liu Qingsong, Yu Yongjae, Pan Yongxin, Zhu Rixiang, and Zhao Xixi
- Subjects
- *
MAGNETIZATION , *FERROMAGNETISM , *MAGNETITE , *PALEOMAGNETISM , *MAGNETIC properties of rocks , *MINERALS - Abstract
In order to isolate magnetic signals carried by single-domain (SD) ferrimagnetic (FM) minerals from multi-domain (MD) FM minerals, we developed a few parameters using partial anhysteretic remanent magnetization (pARM). Because MD fraction contains only soft (easy to be demagnetized) coercivity spectrum, pARM(>20 mT) was sensitive in eliminating MD contributions. Ratio of pARM(5 mT, 10 mT)/pARM(0, 5 mT) is useful in quantifying a relative abundance of mass ratio between SD and MD fractions. These new proxies can quickly characterize the details of grain size distribution of magnetic minerals in paleoclimatic and paleomagnetic studies. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
36. Lights, camera, actin.
- Author
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Rubenstein, Peter and Wen, Kuo-Kuang
- Subjects
- *
ACTIN , *ACTOMYOSIN , *CYTOSKELETAL proteins , *MUSCLE proteins , *PROTEINS , *BRANCHING processes , *STOCHASTIC processes - Abstract
Actin participates in many important biological processes. Currently, intensive investigation is being carried out in a number of laboratories concerning the function of actin in these processes and the molecular basis of its functions. We present a glimpse into four of these areas: actin-like proteins in bacterial cells, actin in the eukaryotic nucleus, the conformational plasticity of the actin filament, and finally, Arp2/3-dependent regulation of actin filament branching and creation of new filament barbed ends. IUBMB Life , 57: 683–687, 2005 [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
37. MOLECULES OF THE BACTERIAL CYTOSKELETON.
- Author
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Löwe, Jan, Van den Ent, Fusinita, and Amos, Linda A.
- Subjects
- *
CYTOSKELETON , *MOLECULES , *TUBULINS , *ACTIN , *BACTERIA - Abstract
The structural elucidation of clear but distant homologs of actin and tubulin in bacteria and GFP labeling of these proteins promises to reinvigorate the field of prokaryotic cell biology. FtsZ (the tubulin homolog) and MreB/ParM (the actin homologs) are indispensable for cellular tasks that require the cell to accurately position molecules, similar to the function of the eukaryotic cytoskeleton. FtsZ is the organizing molecule of bacterial cell division and forms a filamentous ring around the middle of the cell. Many molecules, including MinCDE, SulA, ZipA, and FtsA, assist with this process directly. Recently, genes much more similar to tubulin than to FtsZ have been identified in Verrucomicrobia. MreB forms helices underneath the inner membrane and probably defines the shape of the cell by positioning transmembrane and periplasmic cell wall--synthesizing enzymes. Currently, no interacting proteins are known for MreB and its relatives that help these proteins polymerize or depolymerize at certain times and places inside the cell. It is anticipated that MreB-interacting proteins exist in analogy to the large number of actin binding proteins in eukaryotes. ParM (a plasmid-borne actin homolog) is directly involved in pushing certain single-copy plasmids to the opposite poles by ParR/parC-assisted polymerization into double-helical filaments, much like the filaments formed by actin, F-actin. Mollicutes seem to have developed special systems for cell shape determination and motility, such as the fibril protein in Spiroplasma. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
38. Prokaryotic DNA segregation by an actin‐like filament.
- Author
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Møller‐Jensen, Jakob, Jensen, Rasmus Bugge, Löwe, Jan, and Gerdes, Kenn
- Subjects
- *
SPINDLE apparatus , *FIBERS , *DNA , *ESCHERICHIA coli , *ADENOSINE triphosphatase - Abstract
The mechanisms responsible for prokaryotic DNA segregation are largely unknown. The partitioning locus (par) encoded by the Escherichia coli plasmid R1 actively segregates its replicon to daughter cells. We show here that the ParM ATPase encoded by par forms dynamic actin‐like filaments with properties expected for a force‐generating protein. Filament formation depended on the other components encoded by par, ParR and the centromere‐like parC region to which ParR binds. Mutants defective in ParM ATPase exhibited hyperfilamentation and did not support plasmid partitioning. ParM polymerization was ATP dependent, and depolymerization of ParM filaments required nucleotide hydrolysis. Our in vivo and in vitro results indicate that ParM polymerization generates the force required for directional movement of plasmids to opposite cell poles and that the ParR–parC complex functions as a nucleation point for ParM polymerization. Hence, we provide evidence for a simple prokaryotic analogue of the eukaryotic mitotic spindle apparatus. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
39. Prokaryotic DNA segregation by an actin-like filament.
- Author
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jensen, Jakob Moller-, Jensen, Rasmus Bugge, Lowe, Jan, and Gerdes, Kenn
- Subjects
- *
PROKARYOTES , *DNA , *ESCHERICHIA coli , *ESCHERICHIA , *MICROORGANISMS , *PROTEINS , *HYDROLYSIS - Abstract
The mechanisms responsible for prokaryotic DNA segregation are largely unknown. The partitioning locus (par) encoded by the Escherichia coli plasmid R1 actively segregates its replicon to daughter cells. We show here that the ParM ATPase encoded by par-forms dynamic actin-like filaments with properties expected for a force-generating protein. Filament formation depended on the other components encoded by par, ParR and the centromere-like parC region to which ParR binds. Mutants defective in ParM ATPase exhibited hyperfilamentation and did not support plasmid partitioning. ParM polymerization was ATP dependent, and depolymerization of ParM filaments required nucleotide hydrolysis. Our in vivo and in vitro results indicate that ParM polymerization generates the force required for directional movement of plasmids to opposite cell poles and that the ParR-parC complex functions as a nucleation point for ParM polymerization. Hence, we provide evidence for a simple prokaryotic analogue of the eukaryotic mitotic spindle apparatus. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
40. The structure of a 15-stranded actin-like filament from Clostridium botulinum
- Author
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Yong Zi Tan, Venkata P. Dandey, Lin Jie Lee, Akihiro Narita, David Popp, Kotaro Tanaka, Fujiet Koh, and Robert Robinson
- Subjects
0301 basic medicine ,Models, Molecular ,Protein Conformation ,Science ,General Physics and Astronomy ,02 engineering and technology ,Protomer ,macromolecular substances ,Microfilament ,medicine.disease_cause ,General Biochemistry, Genetics and Molecular Biology ,Article ,Protein filament ,03 medical and health sciences ,Bacterial Proteins ,Microtubule ,Cryoelectron microscopy ,medicine ,Clostridium botulinum ,lcsh:Science ,Cytoskeleton ,Actin ,Multidisciplinary ,Chemistry ,ParM ,General Chemistry ,Gene Expression Regulation, Bacterial ,021001 nanoscience & nanotechnology ,Actins ,Actin Cytoskeleton ,030104 developmental biology ,Biophysics ,lcsh:Q ,0210 nano-technology - Abstract
Microfilaments (actin) and microtubules represent the extremes in eukaryotic cytoskeleton cross-sectional dimensions, raising the question of whether filament architectures are limited by protein fold. Here, we report the cryoelectron microscopy structure of a complex filament formed from 15 protofilaments of an actin-like protein. This actin-like ParM is encoded on the large pCBH Clostridium botulinum plasmid. In cross-section, the ~26 nm diameter filament comprises a central helical protofilament surrounded by intermediate and outer layers of six and eight twisted protofilaments, respectively. Alternating polarity of the layers allows for similar lateral contacts between each layer. This filament design is stiffer than the actin filament, and has likely been selected for during evolution to move large cargos. The comparable sizes of microtubule and pCBH ParM filaments indicate that larger filament architectures are not limited by the protomer fold. Instead, function appears to have been the evolutionary driving force to produce broad, complex filaments., The plasmid-segregating actin-like protein ParM is encoded on the large, toxin carrying plasmid pCBH from Clostridium botulinum. Here the authors present the cryo-EM structure of the ParM filament that is formed from the association of 15 protofilaments and discuss its architecture.
- Published
- 2019
41. Adult With PHOX2B Mutation and Late-Onset Congenital Central Hypoventilation Syndrome
- Author
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Ajay S Kasi, Sheila S. Kun, Iris A Perez, and Thomas G. Keens
- Subjects
Pulmonary and Respiratory Medicine ,Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,Polysomnography ,DNA Mutational Analysis ,Late onset ,Ventilator dependence ,Case Reports ,Congenital central hypoventilation syndrome ,Positive-Pressure Respiration ,03 medical and health sciences ,0302 clinical medicine ,Sleep Apnea Syndromes ,Tracheostomy ,medicine ,Humans ,In patient ,Genetic Testing ,Homeodomain Proteins ,business.industry ,ParM ,Hypoventilation ,Middle Aged ,medicine.disease ,Sleep Apnea, Central ,Phenotype ,030228 respiratory system ,Neurology ,Mutation (genetic algorithm) ,Female ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Transcription Factors - Abstract
PHOX2B 20/27 polyalanine repeat mutation (PARM) in patients with congenital central hypoventilation syndrome (CCHS) is generally associated with full-time ventilator dependence, Hirschsprung disease, and increased risk for cardiac asystole. We follow a 14-year-old boy with CCHS PHOX2B 20/27 PARM who is full-time ventilator dependent via tracheostomy and has Hirschsprung disease. His mother, age 52 years, has a history of prolonged recovery from anesthesia and an elevated serum bicarbonate level of 45 mEq/L discovered on routine blood chemistry. PHOX2B gene mutation analysis was performed and showed an identical 20/27 PARM, diagnostic of CCHS. Late-onset CCHS has been reported in those with 20/24, 20/25 PHOX2B PARM, and in nonpolyalanine repeat mutations. This is the first report of a patient with PHOX2B 20/27 PARM with a mild phenotype diagnosed during adulthood. This unusual presentation supports the screening for PHOX2B mutations in parents of children with CCHS. CITATION: Kasi AS, Kun SS, Keens TG, Perez IA. Adult with PHOX2B mutation and late-onset congenital central hypoventilation syndrome. J Clin Sleep Med. 2018;14(12):2079–2081.
- Published
- 2018
42. The specificity of ParR binding determines the compatibility of conjugative plasmids in Clostridium perfringens
- Author
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Julian I. Rood, Sarah C. Atkinson, Thomas D. Watts, Vicki Adams, Natalie Caltabiano, Carmen Lao, and Daouda A K Traore
- Subjects
Genetics ,0303 health sciences ,030306 microbiology ,Plasmid partitioning ,ParM ,Biology ,Clostridium perfringens ,biology.organism_classification ,medicine.disease_cause ,Bacterial cell structure ,03 medical and health sciences ,Plasmid ,medicine ,Binding site ,Gene ,Bacteria ,030304 developmental biology - Abstract
Plasmids that encode the same replication machinery are generally unable to coexist in the same bacterial cell. However,Clostridium perfringensstrains often carry multiple conjugative toxin or antibiotic resistance plasmids that are closely related and encode similar Rep proteins. In many bacteria, plasmid partitioning upon cell division involves a ParMRC system and there are ~10 different ParMRC families inC. perfringens, with differences in amino acid sequences between each ParM family (15% − 54% identity). Since plasmids encoding genes belonging to the same ParMRC family are not observed in the same strain, these families appear to represent the basis for plasmid compatibility inC. perfringens. To understand this process, we examined the key recognition steps between ParR DNA-binding proteins and theirparCbinding sites. The ParR proteins bound to sequences within aparCsite from the same ParMRC family, but could not interact with aparCsite from a different ParMRC family. These data provide evidence that compatibility of the conjugative toxin plasmids ofC. perfringensis mediated by theirparMRC-like partitioning systems. This process provides a selective advantage by enabling the host bacterium to maintain separate plasmids that encode toxins that are specific for different host targets.
- Published
- 2018
- Full Text
- View/download PDF
43. A research of progressive association rules mining algorithm based on image content.
- Author
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Junfang, Tang
- Abstract
Data mining research and its application is one of the most active branches of the database field, and it is a research hotspot. Multimedia Data Mining MDM has become one of the most challenging areas of information decision area, and many effective association rule mining algorithms have been proposed and improved, but the association rules mining methods and models based on image content are so far different from the ordinary rules because of the complexity of the mining target. The characteristic of two images in a resolution level is the same, but in a finer resolution it is different, so we need a method in which resolution is refined step by step. In this paper, we propose an algorithm of progressive association rules mining based on image content named PARM. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
44. In vitro assembly of the bacterial actin protein MamK from ‘ Candidatus Magnetobacterium casensis’ in the phylum Nitrospirae
- Author
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Jie Wu, Zhaopeng Sun, Wei Lin, Nana Shi, Aihua Deng, Qinyun Sun, Hua Bai, Tingyi Wen, and Yongxin Pan
- Subjects
0301 basic medicine ,Magnetotactic bacteria ,Magnetosome ,lcsh:Animal biochemistry ,Biochemistry ,MreB ,MamK ,Nitrospirae ,Microbiology ,Substrate Specificity ,03 medical and health sciences ,Adenosine Triphosphate ,Bacterial Proteins ,assembly mechanism ,Drug Discovery ,Magnetospirillum ,lcsh:QH573-671 ,lcsh:QP501-801 ,Actin ,Phylogeny ,biology ,Bacteria ,Nucleotides ,lcsh:Cytology ,ParM ,magnetotactic bacteria ,Cell Biology ,biology.organism_classification ,Actins ,Cell biology ,030104 developmental biology ,bacterial actin ,Organelle biogenesis ,Biotechnology ,Research Article - Abstract
Magnetotactic bacteria (MTB), a group of phylogenetically diverse organisms that use their unique intracellular magnetosome organelles to swim along the Earth’s magnetic field, play important roles in the biogeochemical cycles of iron and sulfur. Previous studies have revealed that the bacterial actin protein MamK plays essential roles in the linear arrangement of magnetosomes in MTB cells belonging to the Proteobacteria phylum. However, the molecular mechanisms of multiple-magnetosome-chain arrangements in MTB remain largely unknown. Here, we report that the MamK filaments from the uncultivated ‘Candidatus Magnetobacterium casensis’ (Mcas) within the phylum Nitrospirae polymerized in the presence of ATP alone and were stable without obvious ATP hydrolysis-mediated disassembly. MamK in Mcas can convert NTP to NDP and NDP to NMP, showing the highest preference to ATP. Unlike its Magnetospirillum counterparts, which form a single magnetosome chain, or other bacterial actins such as MreB and ParM, the polymerized MamK from Mcas is independent of metal ions and nucleotides except for ATP, and is assembled into well-ordered filamentous bundles consisted of multiple filaments. Our results suggest a dynamically stable assembly of MamK from the uncultivated Nitrospirae MTB that synthesizes multiple magnetosome chains per cell. These findings further improve the current knowledge of biomineralization and organelle biogenesis in prokaryotic systems. Electronic supplementary material The online version of this article (doi:10.1007/s13238-016-0253-x) contains supplementary material, which is available to authorized users.
- Published
- 2016
45. The prototype foamy virus protease is active independently of the integrase domain
- Author
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Spannaus Ralf, Hartl Maximilian J, Wöhrl Birgitta M, Rethwilm Axel, and Bodem Jochen
- Subjects
Foamy virus ,Regulation of protease activity ,PARM ,Integrase ,GagPol fusion protein ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Abstract Background Recently, contradictory results on foamy virus protease activity were published. While our own results indicated that protease activity is regulated by the viral RNA, others suggested that the integrase is involved in the regulation of the protease. Results To solve this discrepancy we performed additional experiments showing that the protease-reverse transcriptase (PR-RT) exhibits protease activity in vitro and in vivo, which is independent of the integrase domain. In contrast, Pol incorporation, and therefore PR activity in the viral context, is dependent on the integrase domain. To further analyse the regulation of the protease, we incorporated Pol in viruses by expressing a GagPol fusion protein, which supported near wild-type like infectivity. A GagPR-RT fusion, lacking the integrase domain, also resulted in wild-type like Gag processing, indicating that the integrase is dispensable for viral Gag maturation. Furthermore, we demonstrate with a trans-complementation assays that the PR in the context of the PR-RT protein supports in trans both, viral maturation and infectivity. Conclusion We provide evidence that the FV integrase is required for Pol encapsidation and that the FV PR activity is integrase independent. We show that an active PR can be encapsidated in trans as a GagPR-RT fusion protein.
- Published
- 2012
- Full Text
- View/download PDF
46. Examining sensor-based physical activity recognition and monitoring for healthcare using Internet of Things: A systematic review
- Author
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Atif Waraich, Po Yang, Zhikun Deng, Yun Yang, Youbing Zhao, and Jun Qi
- Subjects
QA75 ,Support Vector Machine ,Computer science ,0206 medical engineering ,Feature extraction ,Acceleration ,Physical activity ,Health Informatics ,02 engineering and technology ,Wearable Electronic Devices ,Robustness (computer science) ,Health care ,0202 electrical engineering, electronic engineering, information engineering ,Cluster Analysis ,Humans ,Beneficial effects ,Exercise ,Wearable technology ,Internet ,business.industry ,ParM ,Discriminant Analysis ,R1 ,020601 biomedical engineering ,Data science ,Mobile Applications ,Computer Science Applications ,Linear Models ,020201 artificial intelligence & image processing ,business ,Internet of Things ,Delivery of Health Care ,Wireless Technology ,Algorithms ,Cell Phone - Abstract
Due to importantly beneficial effects on physical and mental health and strong association with many rehabilitation programs, Physical Activity Recognition and Monitoring (PARM) have been considered as a key paradigm for smart healthcare. Traditional methods for PARM focus on controlled environments with the aim of increasing the types of identifiable activity subjects complete and improving recognition accuracy and system robustness by means of novel body-worn sensors or advanced learning algorithms. The emergence of the Internet of Things (IoT) enabling technology is transferring PARM studies to open and connected uncontrolled environments by connecting heterogeneous cost-effective wearable devices and mobile apps. Little is currently known about whether traditional PARM technologies can tackle the new challenges of IoT environments and how to effectively harness and improve these technologies. In an effort to understand the use of IoT technologies in PARM studies, this paper will give a systematic review, critically examining PARM studies from a typical IoT layer-based perspective. It will firstly summarize the state-of-the-art in traditional PARM methodologies as used in the healthcare domain, including sensory, feature extraction and recognition techniques. The paper goes on to identify some new research trends and challenges of PARM studies in the IoT environments, and discusses some key enabling techniques for tackling them. Finally, this paper consider some of the successful case studies in the area and look at the possible future industrial applications of PARM in smart healthcare.
- Published
- 2018
47. Cryo-EM reconstruction of AlfA from Bacillus subtilis reveals the structure of a simplified actin-like filament at 3.4-Å resolution
- Author
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Andrzej Szewczak-Harris and Jan Löwe
- Subjects
DNA, Bacterial ,Models, Molecular ,0301 basic medicine ,Cell division ,Cryo-electron microscopy ,030106 microbiology ,Bacillus subtilis ,macromolecular substances ,Crystallography, X-Ray ,Antiparallel (biochemistry) ,Prokaryotic cytoskeleton ,Protein filament ,03 medical and health sciences ,Bacterial Proteins ,Commentaries ,Cytoskeleton ,Actin ,Genetics ,Multidisciplinary ,biology ,Cryoelectron Microscopy ,ParM ,Biological Sciences ,biology.organism_classification ,Actin Cytoskeleton ,030104 developmental biology ,Biophysics ,Plasmids - Abstract
Low copy-number plasmid pLS32 of Bacillus subtilis subsp. natto contains a partitioning system that ensures segregation of plasmid copies during cell division. The partitioning locus comprises actin-like protein AlfA, adaptor protein AlfB, and the centromeric sequence parN Similar to the ParMRC partitioning system from Escherichia coli plasmid R1, AlfA filaments form actin-like double helical filaments that arrange into an antiparallel bipolar spindle, which attaches its growing ends to sister plasmids through interactions with AlfB and parN Because, compared with ParM and other actin-like proteins, AlfA is highly diverged in sequence, we determined the atomic structure of nonbundling AlfA filaments to 3.4-A resolution by cryo-EM. The structure reveals how the deletion of subdomain IIB of the canonical actin fold has been accommodated by unique longitudinal and lateral contacts, while still enabling formation of left-handed, double helical, polar and staggered filaments that are architecturally similar to ParM. Through cryo-EM reconstruction of bundling AlfA filaments, we obtained a pseudoatomic model of AlfA doublets: the assembly of two filaments. The filaments are antiparallel, as required by the segregation mechanism, and exactly antiphasic with near eightfold helical symmetry, to enable efficient doublet formation. The structure of AlfA filaments and doublets shows, in atomic detail, how deletion of an entire domain of the actin fold is compensated by changes to all interfaces so that the required properties of polymerization, nucleotide hydrolysis, and antiparallel doublet formation are retained to fulfill the system's biological raison d'etre.
- Published
- 2018
48. Structures of actin-like ParM filaments show architecture of plasmid-segregating spindles
- Author
-
Jan Löwe, Tanmay A.M. Bharat, Carsten Sachse, and Garib N. Murshudov
- Subjects
Genetics ,Models, Molecular ,Multidisciplinary ,R1 plasmid ,Cryo-electron microscopy ,Escherichia coli Proteins ,ParM ,Adenylyl Imidodiphosphate ,Cryoelectron Microscopy ,macromolecular substances ,Spindle Apparatus ,Biology ,Antiparallel (biochemistry) ,Crystallography, X-Ray ,Article ,Actins ,Spindle apparatus ,Motor protein ,Protein filament ,Biophysics ,Escherichia coli ,Protein Structure, Quaternary ,Actin ,Plasmids ,Protein Binding - Abstract
Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with centromeric parC plasmid DNA, while facilitating the addition of subunits to ParM filaments. Growing ParMRC spindles push sister plasmids to the cell poles. Here, using modern electron cryomicroscopy methods, we investigate the structures and arrangements of ParM filaments in vitro and in cells, revealing at near-atomic resolution how subunits and filaments come together to produce the simplest known mitotic machinery. To understand the mechanism of dynamic instability, we determine structures of ParM filaments in different nucleotide states. The structure of filaments bound to the ATP analogue AMPPNP is determined at 4.3 A resolution and refined. The ParM filament structure shows strong longitudinal interfaces and weaker lateral interactions. Also using electron cryomicroscopy, we reconstruct ParM doublets forming antiparallel spindles. Finally, with whole-cell electron cryotomography, we show that doublets are abundant in bacterial cells containing low-copy-number plasmids with the ParMRC locus, leading to an asynchronous model of R1 plasmid segregation.
- Published
- 2015
49. Parental modelling of eating behaviours: Observational validation of the Parental Modelling of Eating Behaviours scale (PARM)
- Author
-
Caroline Meyer, Zoe Palfreyman, and Emma Haycraft
- Subjects
Adult ,RJ ,Video Recording ,Child Behavior ,BF ,Body Mass Index ,Developmental psychology ,Eating ,Humans ,Family ,Habituation ,Child ,Maternal Behavior ,Eating behaviour ,Meals ,General Psychology ,Social influence ,Nutrition and Dietetics ,digestive, oral, and skin physiology ,ParM ,Construct validity ,Feeding Behavior ,Role modelling ,Imitative Behavior ,Attitude ,Child, Preschool ,Scale (social sciences) ,Female ,Observational study ,Self Report ,Psychology - Abstract
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Abstract Parents are important role models for their children's eating behaviours. This study aimed to further validate the recently developed Parental Modelling of Eating Behaviours Scale (PARM) by examining the relationships between maternal self-reports on the PARM with the modelling practices exhibited by these mothers during three family mealtime observations. Relationships between observed maternal modelling and maternal reports of children's eating behaviours were also explored. Seventeen mothers with children aged between 2 and 6 years were video recorded at home on three separate occasions whilst eating a meal with their child. Mothers also completed the PARM, the Children's Eating Behaviour Questionnaire and provided demographic information about themselves and their child. Findings provided validation for all three PARM subscales, which were positively associated with their observed counterparts on the observational coding scheme (PARM-O). The results also indicate that habituation to observations did not change the feeding behaviours displayed by mothers. In addition, observed maternal modelling was significantly related to children's food responsiveness (i.e., their interest in and desire for foods), enjoyment of food, and food fussiness. This study makes three important contributions to the literature. It provides construct validation for the PARM measure and provides further observational support for maternal modelling being related to lower levels of food fussiness and higher levels of food enjoyment in their children. These findings also suggest that maternal feeding behaviours remain consistent across repeated observations of family mealtimes, providing validation for previous research which has used single observations.
- Published
- 2015
50. A method to suppress temperature increase in pneumatic artificial rubber muscles
- Author
-
Jun Li, Kenji Kawashima, and Toshiharu Kagawa
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Mechanical Engineering ,General Chemical Engineering ,Compressed air ,ParM ,Aerospace Engineering ,Mechanics ,Operating life ,Nuclear Energy and Engineering ,Natural rubber ,visual_art ,visual_art.visual_art_medium ,Actuator - Abstract
In the present paper, a method by which to suppress the temperature increase in pneumatic artificial rubber muscles is proposed. The pneumatic artificial rubber muscle (PARM) is a flexible actuator. The use of PARMs in industrial and scientific applications has increased significantly as a result of their advantages. Usually, compressed air is charged or discharged from one end of the PARM as it is inflated or deflated. The PARM expands radially and contracts axially when inflated. The closed end is referred to herein as the end part. Since the fluidity of air at the end part of the PARM is low, when a PARM is pressurized repeatedly, the temperature at the end part increases significantly. This temperature increase shortens the operating life of the PARM and limits the characteristics of continuous drive. A method of addressing this temperature increase is proposed herein. A pipeline is installed in the PARM, and compressed air is charged or discharged through the pipeline in order to promote the convection of air at the end part of the PARM. As a result, the temperature increase in the PARM is suppressed. We confirmed experimentally that the proposed method can effectively suppress the temperature increase in the PARM.
- Published
- 2015
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