89 results on '"Edward D. Lowe"'
Search Results
2. Toxin import through the antibiotic efflux channel TolC
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Nicholas G. Housden, Melissa N. Webby, Edward D. Lowe, Tarick J. El-Baba, Renata Kaminska, Christina Redfield, Carol V. Robinson, and Colin Kleanthous
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Science - Abstract
Bacteria can secrete diffusible protein toxins that kill competing bacteria. Here, the authors use biochemical, biophysical and structural analyses to show how one of these toxins exploits TolC (a major antibiotic efflux channel) to transport itself across the outer membrane of target cells.
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- 2021
- Full Text
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3. Pyocin S5 Import into Pseudomonas aeruginosa Reveals a Generic Mode of Bacteriocin Transport
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Hannah M. Behrens, Edward D. Lowe, Joseph Gault, Nicholas G. Housden, Renata Kaminska, T. Moritz Weber, Catriona M. A. Thompson, Gaëtan L. A. Mislin, Isabelle J. Schalk, Daniel Walker, Carol V. Robinson, and Colin Kleanthous
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membrane ,pyocin ,transport ,Microbiology ,QR1-502 - Abstract
ABSTRACT Pyocin S5 (PyoS5) is a potent protein bacteriocin that eradicates the human pathogen Pseudomonas aeruginosa in animal infection models, but its import mechanism is poorly understood. Here, using crystallography, biophysical and biochemical analyses, and live-cell imaging, we define the entry process of PyoS5 and reveal links to the transport mechanisms of other bacteriocins. In addition to its C-terminal pore-forming domain, elongated PyoS5 comprises two novel tandemly repeated kinked 3-helix bundle domains that structure-based alignments identify as key import domains in other pyocins. The central domain binds the lipid-bound common polysaccharide antigen, allowing the pyocin to accumulate on the cell surface. The N-terminal domain binds the ferric pyochelin transporter FptA while its associated disordered region binds the inner membrane protein TonB1, which together drive import of the bacteriocin across the outer membrane. Finally, we identify the minimal requirements for sensitizing Escherichia coli toward PyoS5, as well as other pyocins, and suggest that a generic pathway likely underpins the import of all TonB-dependent bacteriocins across the outer membrane of Gram-negative bacteria. IMPORTANCE Bacteriocins are toxic polypeptides made by bacteria to kill their competitors, making them interesting as potential antibiotics. Here, we reveal unsuspected commonalities in bacteriocin uptake pathways, through molecular and cellular dissection of the import pathway for the pore-forming bacteriocin pyocin S5 (PyoS5), which targets Pseudomonas aeruginosa. In addition to its C-terminal pore-forming domain, PyoS5 is composed of two tandemly repeated helical domains that we also identify in other pyocins. Functional analyses demonstrate that they have distinct roles in the import process. One recognizes conserved sugars projected from the surface, while the other recognizes a specific outer membrane siderophore transporter, FptA, in the case of PyoS5. Through engineering of Escherichia coli cells, we show that pyocins can be readily repurposed to kill other species. This suggests basic ground rules for the outer membrane translocation step that likely apply to many bacteriocins targeting Gram-negative bacteria.
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- 2020
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4. Structures of Teneurin adhesion receptors reveal an ancient fold for cell-cell interaction
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Verity A. Jackson, Dimphna H. Meijer, Maria Carrasquero, Laura S. van Bezouwen, Edward D. Lowe, Colin Kleanthous, Bert J. C. Janssen, and Elena Seiradake
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Science - Abstract
Teneurins are cell-cell adhesion receptors that evolved through horizontal gene transfer in which a bacterial YD-repeat protein fused to a eukaryotic receptor. Here the authors present crystallographic and cryo-EM structures of two Teneurins, revealing an ancient YD-repeat protein super-fold.
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- 2018
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5. Structural and biochemical analysis of human inositol monophosphatase-1 inhibition by ebselen
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Areej Abuhammad, Nicola Laurieri, Alistair Rice, Edward D. Lowe, Nisha Singh, Saleem M. Naser, Samer S. Ratrout, and Grant C. Churchill
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Structural Biology ,General Medicine ,Molecular Biology - Published
- 2023
6. Fusarium verticillioides <scp>NAT1</scp> ( <scp>FDB2</scp> ) N ‐malonyltransferase is structurally, functionally and phylogenetically distinct from its N ‐acetyltransferase ( <scp>NAT</scp> ) homologues
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Eleni‐Pavlina Karagianni, Evanthia Kontomina, Edward D. Lowe, Konstantinos Athanasopoulos, Georgia Papanikolaou, Vasiliki Garefalaki, Varvara Kotseli, Sofia Zaliou, Tom Grimaud, Konstantina Arvaniti, Maria‐Aggeliki Tsatiri, Giannoulis Fakis, Anthony E. Glenn, Pietro Roversi, Areej Abuhammad, Ali Ryan, Robert B. Sim, Edith Sim, and Sotiria Boukouvala
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Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2022
7. Toxin import through the antibiotic efflux channel TolC
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Renata Kaminska, Nicholas G. Housden, Colin Kleanthous, Carol V. Robinson, Edward D. Lowe, Melissa N. Webby, Tarick J. El-Baba, and Christina Redfield
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Models, Molecular ,Bacterial toxins ,Protein Conformation ,Science ,General Physics and Astronomy ,Plasma protein binding ,General Biochemistry, Genetics and Molecular Biology ,Ion Channels ,Article ,03 medical and health sciences ,0302 clinical medicine ,Protein structure ,Bacteriocin ,Bacterial Proteins ,Bacteriocins ,Antibiotics ,Klebsiella ,Membrane proteins ,Inner membrane ,030304 developmental biology ,0303 health sciences ,Bacterial structural biology ,Multidisciplinary ,biology ,Membrane transport protein ,Chemistry ,Cryoelectron Microscopy ,Membrane Transport Proteins ,food and beverages ,Biological Transport ,General Chemistry ,Periplasmic space ,biochemical phenomena, metabolism, and nutrition ,Cell biology ,Anti-Bacterial Agents ,biology.protein ,bacteria ,Efflux ,Bacterial outer membrane ,030217 neurology & neurosurgery ,Bacterial Outer Membrane Proteins ,Protein Binding - Abstract
Bacteria often secrete diffusible protein toxins (bacteriocins) to kill bystander cells during interbacterial competition. Here, we use biochemical, biophysical and structural analyses to show how a bacteriocin exploits TolC, a major outer-membrane antibiotic efflux channel in Gram-negative bacteria, to transport itself across the outer membrane of target cells. Klebicin C (KlebC), a rRNase toxin produced by Klebsiella pneumoniae, binds TolC of a related species (K. quasipneumoniae) with high affinity through an N-terminal, elongated helical hairpin domain common amongst bacteriocins. The KlebC helical hairpin opens like a switchblade to bind TolC. A cryo-EM structure of this partially translocated state, at 3.1 Å resolution, reveals that KlebC associates along the length of the TolC channel. Thereafter, the unstructured N-terminus of KlebC protrudes beyond the TolC iris, presenting a TonB-box sequence to the periplasm. Association with proton-motive force-linked TonB in the inner membrane drives toxin import through the channel. Finally, we demonstrate that KlebC binding to TolC blocks drug efflux from bacteria. Our results indicate that TolC, in addition to its known role in antibiotic export, can function as a protein import channel for bacteriocins., Bacteria can secrete diffusible protein toxins that kill competing bacteria. Here, the authors use biochemical, biophysical and structural analyses to show how one of these toxins exploits TolC (a major antibiotic efflux channel) to transport itself across the outer membrane of target cells.
- Published
- 2021
8. Are shared models always cultural models? A study of the cultural model of affect and emotion in Chuuk
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Edward D. Lowe
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Philosophy of mind ,Typology ,Linguistics and Language ,Cultural models ,Quality (philosophy) ,Experimental and Cognitive Psychology ,Dimension (data warehouse) ,Psychology ,Affect (psychology) ,Cognitive linguistics ,Arousal ,Cognitive psychology - Abstract
This article investigates a theoretical tension in cultural models theory between their sharedness and their origin in social and culturally mediated experiences. To address this tension empirically, this article presents a mixed-methods analysis of the shared understanding of a typology of emotion in Chuuk Lagoon. Based on a review of contemporary theory, one would expect that while people in Chuuk would have distinct cultural models for specific culturally meaningful paradigmatic emotions, the shared model for the entire typology of emotion would be structured by two universal dimensions of core affect (arousal and hedonic quality). But this theoretical literature ignores the importance of an intersubjective dimension of prereflective experience. This dimension may be culturally muted in industrial, educated, and rich contexts where most prior research has been conducted but culturally emphasized in places like Chuuk. The mixed-methods analysis finds that an intersubjective dimension along with a hedonic quality dimension structures the shared model of a typology for affect and emotion in Chuuk, while the arousal dimension found elsewhere is muted. Thus, shared models of affect and emotion are cultural models both in terms of specific, culturally elaborated emotions and in terms of the cultural emphasis given to underlying affective and intersubjective dimensions.
- Published
- 2019
9. Heterotypic interactions drive antibody synergy against a malaria vaccine candidate
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Robert J, Ragotte, David, Pulido, Amelia M, Lias, Doris, Quinkert, Daniel G W, Alanine, Abhishek, Jamwal, Hannah, Davies, Adéla, Nacer, Edward D, Lowe, Geoffrey W, Grime, Joseph J, Illingworth, Robert F, Donat, Elspeth F, Garman, Paul W, Bowyer, Matthew K, Higgins, and Simon J, Draper
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Plasmodium falciparum ,Protozoan Proteins ,Antibodies, Monoclonal ,Antibodies, Protozoan ,Antigens, Protozoan ,Cell Line ,Epitopes ,Drosophila melanogaster ,Immunogenicity, Vaccine ,Malaria Vaccines ,Vaccine Development ,Animals ,Humans ,Malaria, Falciparum - Abstract
Understanding mechanisms of antibody synergy is important for vaccine design and antibody cocktail development. Examples of synergy between antibodies are well-documented, but the mechanisms underlying these relationships often remain poorly understood. The leading blood-stage malaria vaccine candidate, CyRPA, is essential for invasion of Plasmodium falciparum into human erythrocytes. Here we present a panel of anti-CyRPA monoclonal antibodies that strongly inhibit parasite growth in in vitro assays. Structural studies show that growth-inhibitory antibodies bind epitopes on a single face of CyRPA. We also show that pairs of non-competing inhibitory antibodies have strongly synergistic growth-inhibitory activity. These antibodies bind to neighbouring epitopes on CyRPA and form lateral, heterotypic interactions which slow antibody dissociation. We predict that such heterotypic interactions will be a feature of many immune responses. Immunogens which elicit such synergistic antibody mixtures could increase the potency of vaccine-elicited responses to provide robust and long-lived immunity against challenging disease targets.
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- 2021
10. Reconstitution and Structural Analysis of a HECT Ligase-Ubiquitin Complex via an Activity-Based Probe
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Dan Chen, Sonja Lorenz, Ayshwarya Seenivasan, Bing Liu, Edward D. Lowe, and Rahul M. Nair
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HECT domain ,Models, Molecular ,Protein Conformation ,Ubiquitin-Protein Ligases ,macromolecular substances ,Biochemistry ,Catalysis ,Substrate Specificity ,Structure-Activity Relationship ,Ubiquitin ,Catalytic Domain ,Humans ,Amino Acid Sequence ,Cysteine ,Letters ,Ubiquitin activity ,chemistry.chemical_classification ,DNA ligase ,biology ,Propylamines ,Chemistry ,Ubiquitination ,General Medicine ,Enzyme ,Pargyline ,ddc:540 ,Ubiquitin-Conjugating Enzymes ,biology.protein ,Macromolecular Complexes ,Biophysics ,Molecular Medicine - Abstract
ACS chemical biology 16(9), 1615 - 1621 (2021). doi:10.1021/acschembio.1c00433, Ubiquitin activity-based probes have proven invaluable in elucidating structural mechanisms in the ubiquitin system by stabilizing transient macromolecular complexes of deubiquitinases, ubiquitin-activating enzymes, and the assemblies of ubiquitin-conjugating enzymes with ubiquitin ligases of the RING-Between-RING and RING-Cysteine-Relay families. Here, we demonstrate that an activity-based probe, ubiquitin-propargylamine, allows for the preparative reconstitution and structural analysis of the interactions between ubiquitin and certain HECT ligases. We present a crystal structure of the ubiquitin-linked HECT domain of HUWE1 that defines a catalytically critical conformation of the C-terminal tail of the ligase for the transfer of ubiquitin to an acceptor protein. Moreover, we observe that ubiquitin-propargylamine displays selectivity among HECT domains, thus corroborating the notion that activity-based probes may provide entry points for the development of specific, active site-directed inhibitors and reporters of HECT ligase activities., Published by Soc., Washington, DC
- Published
- 2021
11. Mobility and migration in remote Oceania
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Edward D. Lowe
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Geography ,Remote Oceania ,Cartography - Published
- 2021
12. Structural basis for ligand and innate immunity factor uptake by the trypanosome haptoglobin-haemoglobin receptor
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Harriet Lane-Serff, Paula MacGregor, Edward D Lowe, Mark Carrington, and Matthew K Higgins
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trypanosome ,haptoglobin-haemoglobin receptor ,innate immunity ,trypanolytic factor ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The haptoglobin-haemoglobin receptor (HpHbR) of African trypanosomes allows acquisition of haem and provides an uptake route for trypanolytic factor-1, a mediator of innate immunity against trypanosome infection. In this study, we report the structure of Trypanosoma brucei HpHbR in complex with human haptoglobin-haemoglobin (HpHb), revealing an elongated ligand-binding site that extends along its membrane distal half. This contacts haptoglobin and the β-subunit of haemoglobin, showing how the receptor selectively binds HpHb over individual components. Lateral mobility of the glycosylphosphatidylinositol-anchored HpHbR, and a ∼50o kink in the receptor, allows two receptors to simultaneously bind one HpHb dimer. Indeed, trypanosomes take up dimeric HpHb at significantly lower concentrations than monomeric HpHb, due to increased ligand avidity that comes from bivalent binding. The structure therefore reveals the molecular basis for ligand and innate immunity factor uptake by trypanosomes and identifies adaptations that allow efficient ligand uptake in the context of the complex trypanosome cell surface.
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- 2014
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13. Epidemic Suicide in the Context of Modernizing Social Change in Oceania: A Critical Review and Assessment
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Edward D. Lowe
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Sociology and Political Science ,Geography, Planning and Development ,Social change ,Context (language use) ,Sociology ,Criminology - Published
- 2019
14. Structural characterisation of KKT4, an unconventional microtubule-binding kinetochore protein
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Patryk Ludzia, Christina Redfield, Gabriele Marcianò, Bungo Akiyoshi, Shabaz Mohammed, and Edward D. Lowe
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Trypanosoma brucei brucei ,Protozoan Proteins ,Trypanosoma brucei ,Microtubules ,Homology (biology) ,Article ,Chromosome segregation ,03 medical and health sciences ,chemistry.chemical_compound ,NMR spectroscopy ,Structural Biology ,Microtubule ,parasitic diseases ,crosslinking mass spectrometry ,Kinetochores ,Molecular Biology ,030304 developmental biology ,X-ray crystallography ,Coiled coil ,0303 health sciences ,Binding Sites ,BRCT domain ,coiled coil ,biology ,Phosphopeptide ,Kinetochore ,030302 biochemistry & molecular biology ,biology.organism_classification ,kinetochore ,Spindle apparatus ,chemistry ,Biophysics ,kinetoplastid ,KKT4 ,Microtubule-Associated Proteins ,DNA ,Protein Binding - Abstract
Summary The kinetochore is the macromolecular machinery that drives chromosome segregation by interacting with spindle microtubules. Kinetoplastids (such as Trypanosoma brucei), a group of evolutionarily divergent eukaryotes, have a unique set of kinetochore proteins that lack any significant homology to canonical kinetochore components. To date, KKT4 is the only kinetoplastid kinetochore protein that is known to bind microtubules. Here we use X-ray crystallography, NMR spectroscopy, and crosslinking mass spectrometry to characterize the structure and dynamics of KKT4. We show that its microtubule-binding domain consists of a coiled-coil structure followed by a positively charged disordered tail. The structure of the C-terminal BRCT domain of KKT4 reveals that it is likely a phosphorylation-dependent protein-protein interaction domain. The BRCT domain interacts with the N-terminal region of the KKT4 microtubule-binding domain and with a phosphopeptide derived from KKT8. Taken together, these results provide structural insights into the unconventional kinetoplastid kinetochore protein KKT4., Graphical abstract, Highlights • Structures of microtubule-binding and BRCT domains in KKT4 are reported • The microtubule-binding domain consists of a coiled coil and a disordered tail • KKT4 interacts with microtubules via a basic surface at the coiled-coil N terminus • KKT4 has a phosphopeptide-binding BRCT domain, KKT4 is a unique microtubule-binding kinetochore protein in trypanosomes. Structural analyses by Ludzia and colleagues show that its microtubule-binding domain consists of a coiled coil and a positively charged disordered tail. They also demonstrate that the C terminus of KKT4 is a phosphopeptide-binding BRCT domain.
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- 2020
15. Crystal structure of the catalytic C-lobe of the HECT-type ubiquitin ligase E6AP
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Edward D. Lowe, Donald E. Spratt, Lena K. Ries, Christian G. Feiler, Sonja Lorenz, and Anna K. L. Liess
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Models, Molecular ,E3 enzyme ,Ubiquitin-Protein Ligases ,Large scale facilities for research with photons neutrons and ions ,Crystal structure ,macromolecular substances ,X‐ray crystallography ,Crystallography, X-Ray ,Biochemistry ,03 medical and health sciences ,ddc:570 ,Catalytic Domain ,UBE3A ,Humans ,domain swapping ,Molecular Biology ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,DNA ligase ,dimerization ,biology ,030302 biochemistry & molecular biology ,Cell biology ,Ubiquitin ligase ,chemistry ,Biocatalysis ,biology.protein ,Protein Structure Reports - Abstract
The HECT-type ubiquitin ligase E6AP (UBE3A) is critically involved in several neurodevelopmental disorders and human papilloma virus-induced cervical tumorigenesis; the structural mechanisms underlying the activity of this crucial ligase, however, are incompletely understood. Here, we report a crystal structure of the C-terminal lobe (“C-lobe”) of the catalytic domain of E6AP that reveals two molecules in a domain-swapped, dimeric arrangement. Interestingly, the molecular hinge that enables this structural reorganization with respect to the monomeric fold coincides with the active-site region. While such dimerization is unlikely to occur in the context of full-length E6AP, we noticed a similar domain swap in a crystal structure of the isolated C-lobe of another HECT-type ubiquitin ligase, HERC6. This may point to conformational strain in the active-site region of HECT-type ligases with possible implications for catalysis.Significance Statement:The HECT-type ubiquitin ligase E6AP has key roles in human papilloma virus-induced cervical tumorigenesis and certain neurodevelopmental disorders. Here, we present a crystal structure of the C-terminal, catalytic lobe of E6AP, providing basic insight into the conformational properties of this functionally critical region of HECT-type ligases.
- Published
- 2020
16. Introduction
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Michael Schnegg and Edward D. Lowe
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business.industry ,Process (engineering) ,Ethnography ,Sociology ,Software engineering ,business ,Implementation - Published
- 2020
17. A Comparative Ethnographic Study of Suicide Epidemics in Two Pacific Island Societies
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Edward D. Lowe
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Geography ,Ethnology - Published
- 2020
18. Introduction: Person-Centered Approaches in the Study of Culture and Poverty
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Edward D. Lowe and Claudia Strauss
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060101 anthropology ,Sociology and Political Science ,Poverty ,Personhood ,05 social sciences ,Gender studies ,Person centered ,06 humanities and the arts ,0506 political science ,Arts and Humanities (miscellaneous) ,Anthropology ,Cultural models ,Cultural studies ,050602 political science & public administration ,0601 history and archaeology ,Sociology - Published
- 2018
19. High-throughput PIXE as an essential quantitative assay for accurate metalloprotein structural analysis; development and application
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Geoffrey W. Grime, Oliver B. Zeldin, Mary E. Snell, Edward D. Lowe, John F. Hunt, Gaetano T. Montelione, Liang Tong, Edward H. Snell, and Elspeth F. Garman
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Colloid and Surface Chemistry ,Protein Conformation ,Metalloproteins ,General Chemistry ,Crystallography, X-Ray ,Databases, Protein ,Biochemistry ,Catalysis ,High-Throughput Screening Assays - Abstract
Metalloproteins comprise over one-third of proteins, with approximately half of all enzymes requiring metal to function. Accurate identification of these metal atoms and their environment is a prerequisite to understanding biological mechanism. Using ion beam analysis through particle induced X-ray emission (PIXE), we have quantitatively identified the metal atoms in 30 previously structurally characterized proteins using minimal sample volume and a high-throughput approach. Over half of these metals had been misidentified in the deposited structural models. Some of the PIXE detected metals not seen in the models were explainable as artifacts from promiscuous crystallization reagents. For others, using the correct metal improved the structural models. For multinuclear sites, anomalous diffraction signals enabled the positioning of the correct metals to reveal previously obscured biological information. PIXE is insensitive to the chemical environment, but coupled with experimental diffraction data deposited alongside the structural model it enables validation and potential remediation of metalloprotein models, improving structural and, more importantly, mechanistic knowledge.
- Published
- 2019
20. Social Change and Micronesian Suicide Mortality: A Test of Competing Hypotheses
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Edward D. Lowe
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Arts and Humanities (miscellaneous) ,Suicide mortality ,Anthropology ,Social change ,Micronesian ,Psychology (miscellaneous) ,Affect (psychology) ,Psychology ,Test (assessment) ,Demography - Abstract
How do modernizing social changes affect suicide risks for youths in small economically developing societies? Since Durkheim, social researchers have hypothesized that processes of social disintegration and processes of normative cultural disequilibrium can increase suicide rates. A lifestyle incongruity hypothesis has also been proposed. This article tests these competing hypotheses for the epidemic of suicide that occurred on culturally diverse communities of the Pacific Islands of Micronesia. The sample includes 74 municipalities of the Federated States of Micronesia. Multiple regression analyses suggest that the best analytic model includes the degree of urbanization, the levels of social integration, and the incongruity between modern economic resources and achieved modern material lifestyle. These results suggest that researchers should attend more to the way communities aspire to and participate in global markets as opposed to shifting adult role structures and occupations as a site for understanding the relationship between rapid social change and suicide.
- Published
- 2018
21. Investigation of the mycobacterial enzyme HsaD as a potential novel target for anti-tubercular agents using a fragment-based drug design approach
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Areej Abuhammad, Alice Halman, Dimitrios Evangelopoulos, Olga Eleftheriadou, Edith Sim, Sanjib Bhakta, Sebastian Keany, Romain Ballet, Nathan A. Lack, Edward D. Lowe, Elena Polycarpou, Ali Ryan, Christian Sieg, William R. Jacobs, Timothy D. McHugh, and Alessio Ciulli
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0301 basic medicine ,Tuberculosis ,Operon ,01 natural sciences ,law.invention ,Microbiology ,Mycobacterium tuberculosis ,03 medical and health sciences ,law ,Hydrolase ,medicine ,Structure–activity relationship ,Pharmacology ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,Active site ,medicine.disease ,biology.organism_classification ,0104 chemical sciences ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,biology.protein ,Recombinant DNA - Abstract
Background and Purpose: With the emergence of extensively drug-resistant tuberculosis, there is a need for new anti-tubercular drugs that work through novel mechanisms of action. The meta cleavage product hydrolase, HsaD, has been demonstrated to be critical for the survival of Mycobacterium tuberculosis in macrophages and is encoded in an operon involved in cholesterol catabolism, which is identical in M. tuberculosis and M. bovis BCG. Experimental Approach: We generated a mutant strain of M. bovis BCG with a deletion of hsaD and tested its growth on cholesterol. Using a fragment based approach, over 1000 compounds were screened by a combination of differential scanning fluorimetry, NMR spectroscopy and enzymatic assay with pure recombinant HsaD to identify potential inhibitors. We used enzymological and structural studies to investigate derivatives of the inhibitors identified and to test their effects on growth of M. bovis BCG and M. tuberculosis. Key Results: The hsaD deleted strain was unable to grow on cholesterol as sole carbon source but did grow on glucose. Of seven chemically distinct ‘hits’ from the library, two chemical classes of fragments were found to bind in the vicinity of the active site of HsaD by X-ray crystallography. The compounds also inhibited growth of M. tuberculosis on cholesterol. The most potent inhibitor of HsaD was also found to be the best inhibitor of mycobacterial growth on cholesterol-supplemented minimal medium. Conclusions and Implications: We propose that HsaD is a novel therapeutic target, which should be fully exploited in order to design and discover new anti-tubercular drugs.
- Published
- 2017
22. 'Whatever I Have to Do That's Right:' Culture and the Precariousness of Personhood in a Poor Urban Neighborhood
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Edward D, Lowe
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Article - Abstract
This article presents a person-centered case study of one woman’s struggles to realize a meaningful sense of personhood in a low-income urban neighborhood in Milwaukee, Wisconsin. An analysis of longitudinal ethnographic data for this case reveals how everyday aspirations toward a morally resonant lived-sense of personhood were informed by a core assemblage of three cultural models: “providing” and “being there” as a parent and doing so within a framework of “defensive individualism”. This assemblage of cultural models was particularly compelling because of a combination of the embodied residue of childhood experiences and moments of “moral breakdown” in adult life. The experiences of moral breakdown were particularly meaningful because recurrent episodes of material hardship that constantly threatened to upend past efforts to realize a meaningful sense of personhood in everyday life and, in turn, generated a constant effort to reclaim and repair the symbolic markers of an achieved personhood that had been lost. These observations point to a precariousness of personhood that seemed to further motivate an investment in a self-definition in terms of this combination of cultural models.
- Published
- 2018
23. Kinship, Funerals, and the Durability of Culture in Chuuk
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Edward D. Lowe
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060101 anthropology ,030505 public health ,Environmental ethics ,06 humanities and the arts ,Colonialism ,03 medical and health sciences ,Globalization ,Expression (architecture) ,Ethnography ,Kinship ,Funeral Rites ,0601 history and archaeology ,Sociology ,Social institution ,0305 other medical science ,Legitimacy - Abstract
This chapter asks what processes might contribute to the historical durability of cultural beliefs and practices over time and uses the historical durability of funerary rituals in Chuuk Lagoon as its empirical case. Through an analysis of ethnographic materials from Chuuk Lagoon, the author argues that the historical durability of culture requires three things. First, it requires the ongoing availability of cultural propositions in a community that provide for the meaningful assignment of status functions that are associated with social institutions like those of kinship. Second, the historical durability of cultural forms requires repeated Status Function Declarations that assign status functions of kinship to actual people and objects. Finally, in an era where waves of (post)colonialism and globalization provide ready alternatives to locally traditional cultural propositions, people must not only continue to collectively accept or recognize the legitimacy of local cultural propositions, but these must also be related to powerful psychological motivations. In other words, there must exist historically robust local processes for their deep internalization, such that active participation in the ritual practice allows for the fulfillment of needs or the expression of powerful sentiments.
- Published
- 2018
24. Editorial
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Edward D. Lowe
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Sociology and Political Science ,Arts and Humanities (miscellaneous) ,Anthropology - Published
- 2015
25. Toren, Christina, and Simonne Pauwels (eds.): Living Kinship in the Pacific
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Edward D. Lowe
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Arts and Humanities (miscellaneous) ,Anthropology ,Kinship ,Sociology - Published
- 2016
26. Oceania
- Author
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Edward D. Lowe
- Published
- 2017
27. Rapid societal change and mental health vulnerabilities in the Pacific Basin
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Edward D. Lowe
- Subjects
Economic growth ,Political science ,Social change ,Mental health ,Pacific basin - Published
- 2017
28. The N-Terminal Region of Fibrillin-1 Mediates a Bipartite Interaction with LTBP1
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Ian B, Robertson, Hans F, Dias, Isabelle H, Osuch, Edward D, Lowe, Sacha A, Jensen, Christina, Redfield, and Penny A, Handford
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musculoskeletal diseases ,TGF-β ,congenital, hereditary, and neonatal diseases and abnormalities ,Binding Sites ,Fibrillin-1 ,extracellular matrix ,fibrillin ,LTBP ,SAXS ,Article ,NMR ,Molecular Docking Simulation ,Latent TGF-beta Binding Proteins ,Humans ,solution structure ,Protein Binding - Abstract
Summary Fibrillin-1 (FBN1) mutations associated with Marfan syndrome lead to an increase in transforming growth factor β (TGF-β) activation in connective tissues resulting in pathogenic changes including aortic dilatation and dissection. Since FBN1 binds latent TGF-β binding proteins (LTBPs), the major reservoir of TGF-β in the extracellular matrix (ECM), we investigated the structural basis for the FBN1/LTBP1 interaction. We present the structure of a four-domain FBN1 fragment, EGF2-EGF3-Hyb1-cbEGF1 (FBN1E2cbEGF1), which reveals a near-linear domain organization. Binding studies demonstrate a bipartite interaction between a C-terminal LTBP1 fragment and FBN1E2cbEGF1, which lies adjacent to the latency-associated propeptide (LAP)/TGF-β binding site of LTBP1. Modeling of the binding interface suggests that, rather than interacting along the longitudinal axis, LTBP1 anchors itself to FBN1 using two independent epitopes. As part of this mechanism, a flexible pivot adjacent to the FBN1/LTBP1 binding site allows LTBP1 to make contacts with different ECM networks while presumably facilitating a force-induced/traction-based TGF-β activation mechanism., Graphical Abstract, Highlights • The structure of the FBN1 N-terminal region shows a near-linear domain organization • LTBP1 binds to FBN1 via a bipartite mode of interaction involving two discreet sites • This allows LTBP1 to connect 10–12 nm FBN1 microfibrils to other ECM networks • This may facilitate force-induced/traction-based activation of TGF-β via integrins, Improving our knowledge of TGF-β regulation by matrix biomechanics is vital for understanding the biology of this enigmatic growth factor. Robertson et al. present a bipartite model for the structure of the fibrillin-1-LTBP1 interaction that functions as a holdfast for TGF-β in the matrix.
- Published
- 2017
29. Structural basis for duplex RNA recognition and cleavage by Archaeoglobus fulgidus C3PO
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Eneida A. Parizotto, Edward D. Lowe, and James S. Parker
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Protein Conformation ,Archaeal Proteins ,Protein subunit ,Trans-acting siRNA ,TRNA processing ,RNA, Archaeal ,Biology ,Crystallography, X-Ray ,Cleavage (embryo) ,Article ,03 medical and health sciences ,0302 clinical medicine ,Protein structure ,Structural Biology ,RNA interference ,Catalytic Domain ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Archaeoglobus fulgidus ,RNA ,DNA-Binding Proteins ,Protein Subunits ,Biochemistry ,030217 neurology & neurosurgery - Abstract
Oligomeric complexes of Trax and Translin proteins, known as C3POs, participate in several eukaryotic nucleic acid metabolism pathways, including RNA interference and tRNA processing. In RNA interference in humans and Drosophila, C3PO activates the RNA-induced silencing complex (RISC) by removing the passenger strand of the small interfering RNA precursor duplex, using nuclease activity present in Trax. How C3POs engage with nucleic acid substrates is unknown. Here we identify a single protein from Archaeoglobus fulgidus that assembles into an octamer highly similar to human C3PO. The structure in complex with duplex RNA reveals that the octamer entirely encapsulates a single 13-base-pair RNA duplex inside a large inner cavity. Trax-like-subunit catalytic sites target opposite strands of the duplex for cleavage separated by 7 base pairs. The structure provides insight into the mechanism of RNA recognition and cleavage by an archaeal C3PO-like complex.
- Published
- 2013
30. How the biotin-streptavidin interaction was made even stronger: investigation via crystallography and a chimaeric tetramer
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Edward D. Lowe, Mark Howarth, Apurba L. Koner, and Claire E Chivers
- Subjects
Streptavidin ,Biotin binding ,Conformational change ,Hot Temperature ,rmsd, root mean square deviation ,Protein Conformation ,Biotin ,010402 general chemistry ,Crystallography, X-Ray ,Tr1D3, monovalent Tr ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Protein structure ,Tetramer ,Tr4, tetravalent Tr ,streptavidin ,PEG, poly(ethylene glycol) ,Protein Interaction Domains and Motifs ,Molecular Biology ,SA, streptavidin ,Tr, traptavidin ,030304 developmental biology ,0303 health sciences ,Binding Sites ,biology ,D4, a tetramer of dead streptavidin subunits ,Protein Stability ,DPI, diffraction-data precision indicator ,Hydrogen Bonding ,protein engineering ,Cell Biology ,Recombinant Proteins ,0104 chemical sciences ,Crystallography ,chemistry ,avidin ,D, dead streptavidin subunit ,protein–ligand interaction ,Biotinylation ,traptavidin ,biology.protein ,Mutant Proteins ,Apoproteins ,Avidin ,Research Article - Abstract
The interaction between SA (streptavidin) and biotin is one of the strongest non-covalent interactions in Nature. SA is a widely used tool and a paradigm for protein–ligand interactions. We previously developed a SA mutant, termed Tr (traptavidin), possessing a 10-fold lower off-rate for biotin, with increased mechanical and thermal stability. In the present study, we determined the crystal structures of apo-Tr and biotin–Tr at 1.5 Å resolution. In apo-SA the loop (L3/4), near biotin's valeryl tail, is typically disordered and open, but closes upon biotin binding. In contrast, L3/4 was shut in both apo-Tr and biotin–Tr. The reduced flexibility of L3/4 and decreased conformational change on biotin binding provide an explanation for Tr's reduced biotin off- and on-rates. L3/4 includes Ser45, which forms a hydrogen bond to biotin consistently in Tr, but erratically in SA. Reduced breakage of the biotin–Ser45 hydrogen bond in Tr is likely to inhibit the initiating event in biotin's dissociation pathway. We generated a Tr with a single biotin-binding site rather than four, which showed a simi-larly low off-rate, demonstrating that Tr's low off-rate was governed by intrasubunit effects. Understanding the structural features of this tenacious interaction may assist the design of even stronger affinity tags and inhibitors.
- Published
- 2016
31. Piperidinols that show anti-tubercular activity as inhibitors of arylamine N-acetyltransferase: an essential enzyme for mycobacterial survival inside macrophages
- Author
-
Stephen G. Davies, Akane Kawamura, Edward D. Lowe, Isaac M. Westwood, Sanjib Bhakta, Peter T. Seden, Angela J. Russell, Areej Abuhammad, David Staunton, Elizabeth Fullam, Elspeth F. Garman, David L. Wilson, Alun Christopher Garner, and Edith Sim
- Subjects
Bacterial Diseases ,Arylamine N-Acetyltransferase ,Protein Conformation ,Antitubercular Agents ,lcsh:Medicine ,Antimycobacterial ,Biochemistry ,Mice ,0302 clinical medicine ,Piperidines ,Catalytic Domain ,Drug Discovery ,Enzyme Inhibitors ,lcsh:Science ,chemistry.chemical_classification ,0303 health sciences ,Multidisciplinary ,Arylamine N-acetyltransferase ,3. Good health ,Enzymes ,Molecular Docking Simulation ,Infectious Diseases ,030220 oncology & carcinogenesis ,Medicine ,Research Article ,Biotechnology ,endocrine system ,Protein Structure ,Drugs and Devices ,Drug Research and Development ,medicine.drug_class ,Biology ,Protein Chemistry ,Microbiology ,Cell Line ,Mycobacterium ,Mycobacterium tuberculosis ,03 medical and health sciences ,Enzyme activator ,medicine ,Tuberculosis ,Animals ,Humans ,Mode of action ,Microbial Pathogens ,030304 developmental biology ,Dose-Response Relationship, Drug ,Macrophages ,lcsh:R ,fungi ,Proteins ,Tropical Diseases (Non-Neglected) ,biology.organism_classification ,QR ,body regions ,Enzyme Activation ,Enzyme ,chemistry ,Nat ,Enzyme Structure ,lcsh:Q - Abstract
Latent M. tuberculosis infection presents one of the major obstacles in the global eradication of tuberculosis (TB). Cholesterol plays a critical role in the persistence of M. tuberculosis within the macrophage during latent infection. Catabolism of cholesterol contributes to the pool of propionyl-CoA, a precursor that is incorporated into cell-wall lipids. Arylamine N-acetyltransferase (NAT) is encoded within a gene cluster that is involved in the cholesterol sterol-ring degradation and is essential for intracellular survival. The ability of the NAT from M. tuberculosis (TBNAT) to utilise propionyl-CoA links it to the cholesterol-catabolism pathway. Deleting the nat gene or inhibiting the NAT enzyme prevents intracellular survival and results in depletion of cell-wall lipids. TBNAT has been investigated as a potential target for TB therapies. From a previous high-throughput screen, 3-benzoyl-4-phenyl-1-methylpiperidinol was identified as a selective inhibitor of prokaryotic NAT that exhibited antimycobacterial activity. The compound resulted in time-dependent irreversible inhibition of the NAT activity when tested against NAT from M. marinum (MMNAT). To further evaluate the antimycobacterial activity and the NAT inhibition of this compound, four piperidinol analogues were tested. All five compounds exert potent antimycobacterial activity against M. tuberculosis with MIC values of 2.3–16.9 µM. Treatment of the MMNAT enzyme with this set of inhibitors resulted in an irreversible time-dependent inhibition of NAT activity. Here we investigate the mechanism of NAT inhibition by studying protein-ligand interactions using mass spectrometry in combination with enzyme analysis and structure determination. We propose a covalent mechanism of NAT inhibition that involves the formation of a reactive intermediate and selective cysteine residue modification. These piperidinols present a unique class of antimycobacterial compounds that have a novel mode of action different from known anti-tubercular drugs.
- Published
- 2016
32. Structures of mammalian ER alpha-glucosidase II capture the binding modes of broad-spectrum iminosugar antivirals
- Author
-
Ida-Barbara Reca, Dominic S. Alonzi, Angelo Santino, J. L. Kiappes, Pietro Roversi, Lucia Marti, Alessandro T. Caputo, Alice Cross, Souradeep Basu, Nicole Zitzmann, Edward D. Lowe, Benoit Darlot, and Weston B. Struwe
- Subjects
0301 basic medicine ,Glycan ,Protein Conformation ,Stereochemistry ,iminosugar ,Iminosugar ,Drug design ,broad-spectrum antiviral ,eukaryotic secretion ,Biology ,Crystallography, X-Ray ,Endoplasmic Reticulum ,Antiviral Agents ,Catalysis ,Substrate Specificity ,Mice ,03 medical and health sciences ,Protein structure ,Scattering, Small Angle ,Hydrolase ,Animals ,Glycoside Hydrolase Inhibitors ,Multidisciplinary ,030102 biochemistry & molecular biology ,alpha-Glucosidases ,3. Good health ,glycoprotein folding ,Protein Subunits ,030104 developmental biology ,PNAS Plus ,Catalytic cycle ,Biochemistry ,Host cell endoplasmic reticulum ,biology.protein ,Protein quaternary structure ,ER alpha-glucosidase II - Abstract
The biosynthesis of enveloped viruses depends heavily on the host cell endoplasmic reticulum (ER) glycoprotein quality control (QC) machinery. This dependency exceeds the dependency of host glycoproteins, offering a window for the targeting of ERQC for the development of broad-spectrum antivirals. We determined smallangle X-ray scattering (SAXS) and crystal structures of themain ERQC enzyme, ER alpha-glucosidase II (alpha-GluII; from mouse), alone and in complex with key ligands of its catalytic cycle and antiviral iminosugars, including two that are in clinical trials for the treatment of dengue fever. The SAXS data capture the enzyme's quaternary structure and suggest a conformational rearrangement is needed for the simultaneous binding of a monoglucosylated glycan to both subunits. The X-ray structures with key catalytic cycle intermediates highlight that an insertion between the + 1 and + 2 subsites contributes to the enzyme's activity and substrate specificity, and reveal that the presence of D-mannose at the + 1 subsite renders the acid catalyst less efficient during the cleavage of the monoglucosylated substrate. The complexes with iminosugar antivirals suggest that inhibitors targeting a conserved ring of aromatic residues between the alpha-GluII + 1 and + 2 subsites would have increased potency and selectivity, thus providing a template for further rational drug design.
- Published
- 2016
33. Wassmann, Jürg, Birgit Träuble, and Joachim Funke (eds.): Theory of Mind in the Pacific. Reasoning across Cultures
- Author
-
Edward D. Lowe
- Subjects
Psychoanalysis ,Arts and Humanities (miscellaneous) ,Anthropology ,Theory of mind ,Philosophy - Published
- 2014
34. Probing the architecture of the Mycobacterium marinum arylamine N-acetyltransferase active site
- Author
-
Areej Abuhammad, Edith Sim, Elspeth F. Garman, Martin E.M. Noble, Edward D. Lowe, and Elizabeth Fullam
- Subjects
Arylamine N-Acetyltransferase ,Biochemistry ,Catalysis ,Mycobacterium ,Mycobacterium tuberculosis ,Acetyltransferases ,Catalytic Domain ,Drug Discovery ,medicine ,Mycobacterium marinum ,chemistry.chemical_classification ,biology ,Latent tuberculosis ,Arylamine N-acetyltransferase ,fungi ,Cell Biology ,biology.organism_classification ,medicine.disease ,Enzyme ,chemistry ,Nat ,Acetylation ,Crystallization ,Research Article ,Protein Binding ,Biotechnology - Abstract
Treatment of latent tuberculosis infection remains an important goal of global TB eradication. To this end, targets that are essential for intracellular survival of Mycobacterium tuberculosis are particularly attractive. Arylamine N-acetyltransferase (NAT) represents such a target as it is, along with the enzymes encoded by the associated gene cluster, essential for mycobacterial survival inside macrophages and involved in cholesterol degradation. Cholesterol is likely to be the fuel for M. tuberculosis inside macrophages. Deleting the nat gene and inhibiting the NAT enzyme prevents survival of the microorganism in macrophages and induces cell wall alterations, rendering the mycobacterium sensitive to antibiotics to which it is normally resistant. To date, NAT from M. marinum (MMNAT) is considered the best available model for NAT from M. tuberculosis (TBNAT). The enzyme catalyses the acetylation and propionylation of arylamines and hydrazines. Hydralazine is a good acetyl and propionyl acceptor for both MMNAT and TBNAT. The MMNAT structure has been solved to 2.1 Å resolution following crystallisation in the presence of hydralazine and is compared to available NAT structures. From the mode of ligand binding, features of the binding pocket can be identified, which point to a novel mechanism for the acetylation reaction that results in a 3-methyltriazolo[3,4-a]phthalazine ring compound as product.
- Published
- 2010
35. Characterization of a Carbon-Carbon Hydrolase from Mycobacterium tuberculosis Involved in Cholesterol Metabolism
- Author
-
Katherine C. Yam, Robin L. Owen, Lindsay D. Eltis, Edith Sim, Geoff P. Horsman, Nathan A. Lack, and Edward D. Lowe
- Subjects
Conformational change ,Hydrolases ,Stereochemistry ,Static Electricity ,Torsion, Mechanical ,Crystallography, X-Ray ,Models, Biological ,Biochemistry ,Protein Structure, Secondary ,Substrate Specificity ,Serine ,Hydrolase ,Enzyme kinetics ,Molecular Biology ,Alanine ,chemistry.chemical_classification ,Enzyme Catalysis and Regulation ,biology ,Chemistry ,Active site ,Substrate (chemistry) ,Mycobacterium tuberculosis ,Cell Biology ,Solutions ,Kinetics ,Cholesterol ,Enzyme ,Amino Acid Substitution ,Biocatalysis ,Fatty Acids, Unsaturated ,biology.protein ,Mutant Proteins ,Spectrophotometry, Ultraviolet - Abstract
In the recently identified cholesterol catabolic pathway of Mycobacterium tuberculosis, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (HsaD) is proposed to catalyze the hydrolysis of a carbon-carbon bond in 4,5-9,10-diseco-3-hydroxy-5,9,17-tri-oxoandrosta-1(10),2-diene-4-oic acid (DSHA), the cholesterol meta-cleavage product (MCP) and has been implicated in the intracellular survival of the pathogen. Herein, purified HsaD demonstrated 4-33 times higher specificity for DSHA (k(cat)/K(m) = 3.3 +/- 0.3 x 10(4) m(-1) s(-1)) than for the biphenyl MCP 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) and the synthetic analogue 8-(2-chlorophenyl)-2-hydroxy-5-methyl-6-oxoocta-2,4-dienoic acid (HOPODA), respectively. The S114A variant of HsaD, in which the active site serine was substituted with alanine, was catalytically impaired and bound DSHA with a K(d) of 51 +/- 2 mum. The S114A.DSHA species absorbed maximally at 456 nm, 60 nm red-shifted versus the DSHA enolate. Crystal structures of the variant in complex with HOPDA, HOPODA, or DSHA to 1.8-1.9 Aindicate that this shift is due to the enzyme-induced strain of the enolate. These data indicate that the catalytic serine catalyzes tautomerization. A second role for this residue is suggested by a solvent molecule whose position in all structures is consistent with its activation by the serine for the nucleophilic attack of the substrate. Finally, the alpha-helical lid covering the active site displayed a ligand-dependent conformational change involving differences in side chain carbon positions of up to 6.7 A, supporting a two-conformation enzymatic mechanism. Overall, these results provide novel insights into the determinants of specificity in a mycobacterial cholesterol-degrading enzyme as well as into the mechanism of MCP hydrolases.
- Published
- 2010
36. The structure of an integrin/talin complex reveals the basis of inside-out signal transduction
- Author
-
Feng Ye, Nicholas J. Anthis, Kate L. Wegener, Benjamin T. Goult, David R. Critchley, Edward D. Lowe, Ioannis Vakonakis, Iain D. Campbell, Mark H. Ginsberg, Neil Bate, and Chungho Kim
- Subjects
Models, Molecular ,Talin ,Integrins ,animal structures ,Macromolecular Substances ,Molecular Sequence Data ,Integrin ,CHO Cells ,macromolecular substances ,Biology ,Models, Biological ,CD49c ,Article ,General Biochemistry, Genetics and Molecular Biology ,Focal adhesion ,Cell membrane ,Cricetulus ,Cricetinae ,medicine ,Animals ,Amino Acid Sequence ,Cell adhesion ,Molecular Biology ,Sequence Homology, Amino Acid ,General Immunology and Microbiology ,General Neuroscience ,Cell Membrane ,Cell Polarity ,Talin binding ,Protein Structure, Tertiary ,Cell biology ,medicine.anatomical_structure ,Integrin alpha M ,biology.protein ,Integrin, beta 6 ,Protein Binding ,Signal Transduction - Abstract
Fundamental to cell adhesion and migration, integrins are large heterodimeric membrane proteins that uniquely mediate inside-out signal transduction, whereby adhesion to the extracellular matrix is activated from within the cell by direct binding of talin to the cytoplasmic tail of the beta integrin subunit. Here, we report the first structure of talin bound to an authentic full-length beta integrin tail. Using biophysical and whole cell measurements, we show that a specific ionic interaction between the talin F3 domain and the membrane-proximal helix of the beta tail disrupts an integrin alpha/beta salt bridge that helps maintain the integrin inactive state. Second, we identify a positively charged surface on the talin F2 domain that precisely orients talin to disrupt the heterodimeric integrin transmembrane (TM) complex. These results show key structural features that explain the ability of talin to mediate inside-out TM signalling.
- Published
- 2009
37. Structure and Interdomain Interactions of a Hybrid Domain: A Disulphide-Rich Module of the Fibrillin/LTBP Superfamily of Matrix Proteins
- Author
-
Penny A. Handford, Edward D. Lowe, Sarah Iqbal, Christina Redfield, and Sacha A. Jensen
- Subjects
Models, Molecular ,Protein Conformation ,PROTEINS ,Molecular Sequence Data ,Endothelial Growth Factors ,Biology ,Fibrillins ,DNA-binding protein ,Article ,Structure-Activity Relationship ,03 medical and health sciences ,Protein structure ,Structural Biology ,Calcium-binding protein ,Amino Acid Sequence ,Disulfides ,Binding site ,Molecular Biology ,Peptide sequence ,030304 developmental biology ,0303 health sciences ,Binding Sites ,Calcium-Binding Proteins ,Microfilament Proteins ,030302 biochemistry & molecular biology ,Protein Structure, Tertiary ,3. Good health ,Crystallography ,Latent TGF-beta binding protein ,Latent TGF-beta Binding Proteins ,Biophysics ,Calcium ,CELLBIO ,Fibrillin - Abstract
The fibrillins and latent transforming growth factor-beta binding proteins (LTBPs) form a superfamily of structurally-related proteins consisting of calcium-binding epidermal growth factor-like (cbEGF) domains interspersed with 8-cysteine-containing transforming growth factor beta-binding protein-like (TB) and hybrid (hyb) domains. Fibrillins are the major components of the extracellular 10-12 nm diameter microfibrils, which mediate a variety of cell-matrix interactions. Here we present the crystal structure of a fibrillin-1 cbEGF9-hyb2-cbEGF10 fragment, solved to 1.8 A resolution. The hybrid domain fold is similar, but not identical, to the TB domain fold seen in previous fibrillin-1 and LTBP-1 fragments. Pairwise interactions with neighboring cbEGF domains demonstrate extensive interfaces, with the hyb2-cbEGF10 interface dependent on Ca(2+) binding. These observations provide accurate constraints for models of fibrillin organization within the 10-12 nm microfibrils and provide further molecular insights into how Ca(2+) binding influences the intermolecular interactions and biomechanical properties of fibrillin-1.
- Published
- 2009
38. Structure of Daidzin, a Naturally Occurring Anti-Alcohol-Addiction Agent, in Complex with Human Mitochondrial Aldehyde Dehydrogenase
- Author
-
Guang-Yao Gao, Edward D Lowe, Louise N Johnson, and Wing Ming Keung
- Subjects
Models, Molecular ,Stereochemistry ,Aldehyde dehydrogenase ,Crystallography, X-Ray ,Aldehyde Dehydrogenase 1 Family ,Structure-Activity Relationship ,chemistry.chemical_compound ,Oxidoreductase ,Cricetinae ,Drug Discovery ,Animals ,Humans ,Structure–activity relationship ,Binding site ,Daidzin ,ALDH2 ,chemistry.chemical_classification ,Binding Sites ,Natural product ,Molecular Structure ,biology ,Aldehyde Dehydrogenase, Mitochondrial ,Retinal Dehydrogenase ,Aldehyde Dehydrogenase ,Isoflavones ,Mitochondria ,Behavior, Addictive ,Isoenzymes ,Alcoholism ,chemistry ,Biochemistry ,biology.protein ,Molecular Medicine - Abstract
The ALDH2*2 gene encoding the inactive variant form of mitochondrial aldehyde dehydrogenase (ALDH2) protects nearly all carriers of this gene from alcoholism. Inhibition of ALDH2 has hence become a possible strategy to treat alcoholism. The natural product 7-O-glucosyl-4'-hydroxyisoflavone (daidzin), isolated from the kudzu vine ( Peruraria lobata), is a specific inhibitor of ALDH2 and suppresses ethanol consumption. Daidzin is the active principle in a herbal remedy for "alcohol addiction" and provides a lead for the design of improved ALDH2. The structure of daidzin/ALDH2 in complex at 2.4 A resolution shows the isoflavone moiety of daidzin binding close to the aldehyde substrate-binding site in a hydrophobic cleft and the glucosyl function binding to a hydrophobic patch immediately outside the isoflavone-binding pocket. These observations provide an explanation for both the specificity and affinity of daidzin (IC50 =80 nM) and the affinity of analogues with different substituents at the glucosyl position.
- Published
- 2008
39. An Integrin Phosphorylation Switch
- Author
-
Edward D. Lowe, Camilla L. Oxley, Nicholas J. Anthis, Ioannis Vakonakis, Iain D. Campbell, and Kate L. Wegener
- Subjects
Phosphotyrosine binding ,Integrin ,macromolecular substances ,Cell Biology ,Plasma protein binding ,Biology ,Biochemistry ,CD49c ,Talin binding ,Cell biology ,Collagen receptor ,Integrin alpha M ,biology.protein ,Integrin, beta 6 ,Molecular Biology - Abstract
Integrins play a fundamental role in cell migration and adhesion; knowledge of how they are regulated and controlled is vital for understanding these processes. Recent work showed that Dok1 negatively regulates integrin activation, presumably by competition with talin. To understand how this occurs, we used NMR spectroscopy and x-ray crystallography to investigate the molecular details of interactions with integrins. The binding affinities of β3 integrin tails for the Dok1 and talin phosphotyrosine binding domains were quantified using 15N-1H hetero-nuclear single quantum correlation titrations, revealing that the unphosphorylated integrin tail binds more strongly to talin than Dok1. Chemical shift mapping showed that unlike talin, Dok1 exclusively interacts with the canonical NPXY motif of the β3 integrin tail. Upon phosphorylation of Tyr747 in the β3 integrin tail, however, Dok1 then binds much more strongly than talin. Thus, we show that phosphorylation of Tyr747 provides a switch for integrin ligand binding. This switch may represent an in vivo mechanism for control of integrin receptor activation. These results have implications for the control of integrin signaling by proteins containing phosphotyrosine binding domains.
- Published
- 2008
40. Expanding the Family Economic Stress Model: Insights From a Mixed-Methods Approach
- Author
-
Edward D. Lowe, Rashmita S. Mistry, Aprile D. Benner, and Nina Chien
- Subjects
Arts and Humanities (miscellaneous) ,Poverty ,Anthropology ,Parenting styles ,Poison control ,Human factors and ergonomics ,Family income ,Basic needs ,Psychology ,Social psychology ,Social Sciences (miscellaneous) ,Structural equation modeling ,Qualitative research - Abstract
The current study used a mixed-methods approach to examine how low-income mothers managed their household economies, their experiences of economic pressure, and the consequences for family and child functioning. Qualitative analyses (N = 32 families) revealed that experiences of economic pressure were associated with an inability to afford both basic needs and some modest but highly valued “extras.” To meet demands, mothers reported using a variety of strategies, including instrumental support from friends and family members and other financial strategies. Results from the quantitative analyses (N= 516 families; 800 children, ages 6 – 15) were generally consistent with patterns observed in the qualitative analyses and extended the findings to include effects on parenting practices and children’s behavioral functioning.
- Published
- 2008
41. Structural Analysis of the Interactions Between Paxillin LD Motifs and α-Parvin
- Author
-
Maria K. Hoellerer, Sonja Lorenz, Iain D. Campbell, Martin E.M. Noble, Edward D. Lowe, and Ioannis Vakonakis
- Subjects
Models, Molecular ,PROTEINS ,Amino Acid Motifs ,Molecular Sequence Data ,Antiparallel (biochemistry) ,Calponin homology domain ,Leucine-Rich Repeat Proteins ,Article ,Focal adhesion ,03 medical and health sciences ,Structural Biology ,Protein Interaction Mapping ,Humans ,Degeneracy (biology) ,Actinin ,Amino Acid Sequence ,Binding site ,Molecular Biology ,Paxillin ,030304 developmental biology ,0303 health sciences ,biology ,Sequence Homology, Amino Acid ,030302 biochemistry & molecular biology ,Microfilament Proteins ,Signal transducing adaptor protein ,3. Good health ,Biochemistry ,biology.protein ,Biophysics ,Linker ,Protein Binding ,Signal Transduction - Abstract
The adaptor protein paxillin contains five conserved leucine-rich (LD) motifs that interact with a variety of focal adhesion proteins, such as alpha-parvin. Here, we report the first crystal structure of the C-terminal calponin homology domain (CH(C)) of alpha-parvin at 1.05 A resolution and show that it is able to bind all the LD motifs, with some selectivity for LD1, LD2, and LD4. Cocrystal structures with these LD motifs reveal the molecular details of their interactions with a common binding site on alpha-parvin-CH(C), which is located at the rim of the canonical fold and includes part of the inter-CH domain linker. Surprisingly, this binding site can accommodate LD motifs in two antiparallel orientations. Taken together, these results reveal an unusual degree of binding degeneracy in the paxillin/alpha-parvin system that may facilitate the assembly of dynamic signaling complexes in the cell.
- Published
- 2008
42. Divergence of Cofactor Recognition across Evolution: Coenzyme A Binding in a Prokaryotic Arylamine N-Acetyltransferase
- Author
-
Matthew C. Anderton, Elizabeth Fullam, Edith Sim, Edward D. Lowe, Martin E.M. Noble, and Isaac M. Westwood
- Subjects
Models, Molecular ,endocrine system ,Arylamine N-Acetyltransferase ,Stereochemistry ,Coenzyme A ,Molecular Sequence Data ,Crystallography, X-Ray ,Mass Spectrometry ,Protein Structure, Secondary ,Cofactor ,Mycobacterium ,Substrate Specificity ,Conserved sequence ,Evolution, Molecular ,Open Reading Frames ,chemistry.chemical_compound ,Structural Biology ,Transferase ,Amino Acid Sequence ,Cloning, Molecular ,Molecular Biology ,Conserved Sequence ,Mycobacterium marinum ,Sequence Homology, Amino Acid ,Arylamine N-acetyltransferase ,biology ,fungi ,Acetyl-CoA ,Genetic Variation ,Hydrogen Bonding ,biology.organism_classification ,Recombinant Proteins ,Protein Structure, Tertiary ,body regions ,Kinetics ,Models, Chemical ,Prokaryotic Cells ,chemistry ,Biochemistry ,Nat ,biology.protein ,Dimerization ,Hydrophobic and Hydrophilic Interactions ,Protein Binding - Abstract
Arylamine N-acetyltransferase (NAT) enzymes are widespread in nature. They serve to acetylate xenobiotics and/or endogenous substrates using acetyl coenzyme A (CoA) as a cofactor. Conservation of the architecture of the NAT enzyme family from mammals to bacteria has been demonstrated by a series of prokaryotic NAT structures, together with the recently reported structure of human NAT1. We report here the cloning, purification, kinetic characterisation and crystallographic structure determination of NAT from Mycobacterium marinum, a close relative of the pathogenic Mycobacterium tuberculosis. We have also determined the structure of M. marinum NAT in complex with CoA, shedding the first light on cofactor recognition in prokaryotic NATs. Surprisingly, the principal CoA recognition site in M. marinum NAT is located some 30 A from the site of CoA recognition in the recently deposited structure of human NAT2 bound to CoA. The structure explains the Ping-Pong Bi-Bi reaction mechanism of NAT enzymes and suggests mechanisms by which the acetylated enzyme intermediate may be protected. Recognition of CoA in a much wider groove in prokaryotic NATs suggests that this subfamily may accommodate larger substrates than is the case for human NATs and may assist in the identification of potential endogenous substrates. It also suggests the cofactor-binding site as a unique subsite to target in drug design directed against NAT in mycobacteria.
- Published
- 2008
43. Structures of the Dsk2 UBL and UBA domains and their complex
- Author
-
Edward D. Lowe, Jean-François Trempe, Jane A. Endicott, N.R. Brown, Na'il Hasan, Louise N. Johnson, Martin E.M. Noble, and Laura Fonso
- Subjects
Models, Molecular ,Proteasome Endopeptidase Complex ,Saccharomyces cerevisiae Proteins ,Protein subunit ,Molecular Sequence Data ,Cell Cycle Proteins ,Saccharomyces cerevisiae ,Plasma protein binding ,Crystallography, X-Ray ,Protein structure ,Ubiquitin ,Structural Biology ,Amino Acid Sequence ,Binding site ,Polyubiquitin ,Ubiquitins ,Peptide sequence ,Sequence Deletion ,Binding Sites ,Sequence Homology, Amino Acid ,biology ,Chemistry ,General Medicine ,Surface Plasmon Resonance ,Protein Structure, Tertiary ,Cell biology ,DNA-Binding Proteins ,Crystallography ,Proteasome ,biology.protein ,Crystallization ,Protein Binding - Abstract
The yeast proteins Dsk2 and Rad23 belong to a family of proteins that contain an N-terminal ubiquitin-like domain (UBL) and a C-terminal ubiquitin-associated domain (UBA). Both Dsk2 and Rad23 function as adaptors to target ubiquitin-labelled proteins to the proteasome through recognition of polyubiquitin (four or more K48-linked ubiquitins) by their UBA domains and to the yeast proteasomal subunit Rpn1 by their UBL domains. The crystal structures of the Dsk2 UBL domain, the Dsk2 UBA domain and the Dsk2 UBA-UBL complex are reported. In the crystal, the Dsk2 UBA domains associate through electrostatic interactions to form ninefold helical ribbons that leave the ubiquitin-binding surface exposed. The UBA-UBL complex explains the reduced affinity of the UBA domain for UBL compared with ubiquitin and has implications for the regulation of Dsk2 adaptor function during ubiquitin-mediated proteasomal targeting. A model is discussed in which two or more Dsk2 UBA molecules may selectively bind to K48-linked polyubiquitin.
- Published
- 2006
44. Author response: Structural basis for ligand and innate immunity factor uptake by the trypanosome haptoglobin-haemoglobin receptor
- Author
-
Harriet Lane-Serff, Mark Carrington, Paula MacGregor, Matthew K. Higgins, and Edward D. Lowe
- Subjects
Innate immune system ,biology ,Chemistry ,Haptoglobin ,biology.protein ,Receptor ,Ligand (biochemistry) ,Cell biology - Published
- 2014
45. The Crystal Structure of Human CDK7 and Its Protein Recognition Properties
- Author
-
Louise N. Johnson, Edward D. Lowe, N.R. Brown, and Graziano Lolli
- Subjects
Models, Molecular ,Cyclin H ,Protein Conformation ,Molecular Sequence Data ,Crystallography, X-Ray ,MAP2K7 ,Adenosine Triphosphate ,Structural Biology ,Cyclin-dependent kinase ,Humans ,Amino Acid Sequence ,Phosphorylation ,Protein kinase A ,Molecular Biology ,Cyclin-dependent kinase 1 ,Binding Sites ,Sequence Homology, Amino Acid ,biology ,Kinase ,Chemistry ,Cyclin-dependent kinase 4 ,Cyclin-dependent kinase 2 ,Cyclin-dependent kinase 3 ,Cyclin-Dependent Kinases ,Cell biology ,Transcription Factor TFIIH ,Biochemistry ,Cyclin-dependent kinase complex ,biology.protein ,Cyclin-dependent kinase 7 ,Cyclin-Dependent Kinase-Activating Kinase ,Protein Binding - Abstract
CDK7, a member of the cyclin-dependent protein kinase family, regulates the activities of other CDKs through phosphorylation on their activation segment and hence contributes to control of the eukaryotic cell cycle. CDK7 also assists in the regulation of transcription as part of the transcription factor TFIIH complex. For maximum activity and stability, CDK7 requires phosphorylation, association with cyclin H, and association with a third protein, MAT1. We have determined the crystal structure of human CDK7 in complex with ATP at 3 Å resolution. The kinase is in the inactive conformation, similar to that observed for inactive CDK2. The activation segment is phosphorylated at Thr170 and is in a defined conformation that differs from that in phospho-CDK2 and phospho-CDK2/cyclin A. The functional properties of the enzyme against CDK2 and CTD as substrates are characterized through kinase assays. Experiments confirm that CDK7 is not a substrate for kinase-associated phosphatase.
- Published
- 2004
46. ‘You have to push it—who's gonna raise your kids?’: situating child care and child care subsidy use in the daily routines of lower income families
- Author
-
Edward D. Lowe and Thomas S. Weisner
- Subjects
Economic growth ,Child care ,Activities of daily living ,Sociology and Political Science ,Control (management) ,Flexibility (personality) ,Subsidy ,Child development ,Education ,Developmental psychology ,Intervention (counseling) ,Ethnography ,Developmental and Educational Psychology ,Economics - Abstract
We use qualitative and quantitative data from a multi-year study of low-income families included in New Hope, an experimental anti-poverty intervention in Milwaukee, Wisconsin to understand why low-income families’ use of program-based child care as well as subsidies offered to pay for such care is often low and/or episodic. Ethnographic analyses from 38 families in experimental and control groups suggest that child care choices and subsidy use must fit into the family daily routines and with the beliefs people have about child care. Both ecocultural theory and parents’ own reports of child care decisions suggest four themes accounting for child care choice: material and social resources; conflicts in the family; values and beliefs about parenting and child development; and predictability and stability of child care. Child care subsidy programs can be more effective if they offer greater flexibility and a range of options that better fit into the varied daily routines of the low-income families they are intended to serve.
- Published
- 2004
47. Can child care assistance in welfare and employment programs support the employment of low-income families?
- Author
-
Danielle A. Crosby, Aletha C. Huston, Edward D. Lowe, and Lisa A. Gennetian
- Subjects
Child care ,Labour economics ,Public Administration ,Sociology and Political Science ,Random assignment ,media_common.quotation_subject ,Public policy ,Subsidy ,Employability ,Policy analysis ,General Business, Management and Accounting ,Expanded access ,Business ,Welfare ,media_common - Abstract
Policymakers have long recognized child care as a key ingredient in low-income parents' employability. We examine the effects of expansions in child care policies that were bundled with a mix of employment-related policies and implemented as part of several random assignment studies on families' child care access and cost. Almost all of these welfare and employment programs increased employment and led to concomitant increases in the use of child care, especially paid child care. Only the programs that also expanded access or affordability of child care consistently increased the use of child care subsidies and reduced out-of-pocket costs to parents, allowing parents to purchase center-based care. With one exception, such programs had small effects on employment-related child care problems, suggesting that broader and more generous targeting of child care assistance may be important for achieving the goal of enhancing the stability of employment among low-income families. © 2004 by the Association for Public Policy Analysis and Management.
- Published
- 2004
48. Impacts of Children With Troubles on Working Poor Families: Mixed-Method and Experimental Evidence
- Author
-
Edward D. Lowe, Thomas S. Weisner, and Lucinda P. Bernheimer
- Subjects
medicine.medical_specialty ,Coping (psychology) ,Poverty ,Working poor ,Public health ,Rehabilitation ,Social environment ,Mental health ,Education ,Developmental psychology ,General Health Professions ,Learning disability ,medicine ,medicine.symptom ,Psychology ,Socioeconomic status - Abstract
Mixed-method and experimental data on working poor families and children with troubles participating in the New Hope anti-poverty experimental initiative in Milwaukee are described. Sixty percent of these families had at least one child who had significant problems (learning, school achievement and/or behavior, home behavior, retardation, other disabilities). Control group families with children who had troubles had more difficulties in sustaining their family routine than did New Hope experimental families. In the context of the many other challenges these parents face, adaptation to children with troubles does not stand out as sharply compared to middle-class European American families. There is less family adaptation specifically due to, or in response to, the troubled child, and more adaptation to the struggles of making ends meet.
- Published
- 2003
49. The crystal structure of the human polo-like kinase-1 polo box domain and its phospho-peptide complex
- Author
-
Erich A. Nigg, Louise N. Johnson, Edward D. Lowe, Kin‐Yip Cheng, and John Sinclair
- Subjects
Models, Molecular ,Protein Folding ,Macromolecular Substances ,Molecular Sequence Data ,Static Electricity ,Cell Cycle Proteins ,Polo-like kinase ,Protein Serine-Threonine Kinases ,Biology ,Crystallography, X-Ray ,PLK1 ,Protein Structure, Secondary ,General Biochemistry, Genetics and Molecular Biology ,Protein structure ,Proto-Oncogene Proteins ,Humans ,Amino Acid Sequence ,Kinase activity ,Central spindle ,Molecular Biology ,Mitosis ,Sequence Homology, Amino Acid ,General Immunology and Microbiology ,Kinetochore ,General Neuroscience ,Articles ,Recombinant Proteins ,Protein Structure, Tertiary ,Cell biology ,Biochemistry ,Protein Kinases ,Cytokinesis - Abstract
Human polo-like kinase Plk1 localizes to the centrosomes, kinetochores and central spindle structures during mitosis. It plays an essential role in promoting mitosis and cytokinesis through phosphorylation of a number of different substrates. Kinase activity is regulated by a conserved C-terminal domain, termed the polo box domain (PBD), which acts both as an autoinhibitory domain and as a subcellular localization domain. We have determined the crystal structure of Plk1 PBD (residues 367-603) to 2.2 A resolution and the structure of a phospho-peptide-PBD (residues 345-603) complex to 2.3 A resolution. The two polo boxes of the PBD exhibit identical folds based on a six-stranded beta-sheet and an alpha-helix, despite only 12% sequence identity. The phospho-peptide binds at a site between the two polo boxes. It makes a short antiparallel beta-sheet connection and critical contacts to residues Trp414, Leu490, His538 and Lys540. Most of these residues had been shown to be important for biological activity through mutational studies. The results provide an explanation for phospho-peptide recognition and create the basis for new functional studies.
- Published
- 2003
50. Being There: The Fieldwork Encounter and the Making of Truth. JohnBorneman and AbdellahHammoudi, eds. Berkeley: University of California Press. 2009. i+280 pp
- Author
-
Edward D. Lowe
- Subjects
Sociology and Political Science ,Arts and Humanities (miscellaneous) ,Anthropology ,Environmental ethics ,Sociology ,Making-of - Published
- 2012
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