22 results on '"Noelia Roman"'
Search Results
2. Embedding Equity: Online Tutor Support to Provide Effective Feedforward on Assessments
- Author
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Sarah Teakel, Kelly Linden, Neil van der Ploeg, and Noelia Roman
- Abstract
Sustainable and innovative programs to support students in their transition to university and improve student progress rates and retention are in high demand and short supply. An institution-wide model was established for an online Embedded Tutor Program. The program supports commencing undergraduate students and is sustainable post-pandemic. Tutors with unit-specific knowledge were embedded in 98 first-year unit offerings across the university in 2022. Tutors met with students via Zoom to provide feedforward on a written assessment. Of the 1080 students who met with a tutor, assessment marks were on average 8% higher and cumulative unit marks were 15% higher, and the one-on-one tutor support improved students' perceived confidence, overall learning and satisfaction. The Embedded Tutor Program had positive outcomes for all participants; however, students with multiple equity factors benefited the most from the support.
- Published
- 2024
- Full Text
- View/download PDF
3. Understanding University Failure: Zero-Fails, COVID-19 and Commencing Student Outcomes at an Australian University
- Author
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Neil van der Ploeg, Kelly Linden, Ben Hicks, and Noelia Roman
- Abstract
Universities actively promote themselves to potential students, control admissions and deliver programs of study. For most students globally, there are financial costs to attending university. At the extreme end of failure are students who receive 'zero-fails': they enrol, do not submit any assessments, and receive a mark of 0 out of 100. A quantitative descriptive analysis was performed and provides student performance details for bachelor-level students enrolled in a large, regional Australian university from 2019-2021. At a unit level, zero-fails accounted for 20% of all failing grades. There was a significant increase in zero-fail grades in 2020 and 2021 compared to 2019. However, zero-fails are not entirely a COVID-19 phenomenon. Only 8% of students who received any zero-fail grade in their commencing semester of study continued onto their second semester and passed most of their units. We argue universities operating in countries with deferred payment schemes such as Australia and the United Kingdom have a responsibility to track unit failure in finer detail and consider ways to mitigate debt associated with students who are clearly not receiving value from their educational experience. This must be done as we continue to expand higher education opportunities to students from non-traditional backgrounds.
- Published
- 2024
- Full Text
- View/download PDF
4. Novel Flavivirus Antiviral That Targets the Host Nuclear Transport Importin α/β1 Heterodimer
- Author
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Sundy N. Y. Yang, Sarah C. Atkinson, Johanna E. Fraser, Chunxiao Wang, Belinda Maher, Noelia Roman, Jade K. Forwood, Kylie M. Wagstaff, Natalie A. Borg, and David A. Jans
- Subjects
flavivirus ,nuclear transport inhibitors ,importins ,viral infection ,dengue virus ,Cytology ,QH573-671 - Abstract
Dengue virus (DENV) threatens almost 70% of the world’s population, with no effective vaccine or therapeutic currently available. A key contributor to infection is nuclear localisation in the infected cell of DENV nonstructural protein 5 (NS5) through the action of the host importin (IMP) α/β1 proteins. Here, we used a range of microscopic, virological and biochemical/biophysical approaches to show for the first time that the small molecule GW5074 has anti-DENV action through its novel ability to inhibit NS5–IMPα/β1 interaction in vitro as well as NS5 nuclear localisation in infected cells. Strikingly, GW5074 not only inhibits IMPα binding to IMPβ1, but can dissociate preformed IMPα/β1 heterodimer, through targeting the IMPα armadillo (ARM) repeat domain to impact IMPα thermal stability and α-helicity, as shown using analytical ultracentrifugation, thermostability analysis and circular dichroism measurements. Importantly, GW5074 has strong antiviral activity at low µM concentrations against not only DENV-2, but also zika virus and West Nile virus. This work highlights DENV NS5 nuclear targeting as a viable target for anti-flaviviral therapeutics.
- Published
- 2019
- Full Text
- View/download PDF
5. Structural characterization of a Gcn5-related N-acetyltransferase from Staphylococcus aureus.
- Author
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Parul Srivastava, Yogesh B Khandokar, Crystall M D Swarbrick, Noelia Roman, Zainab Himiari, Subir Sarker, Shane R Raidal, and Jade K Forwood
- Subjects
Medicine ,Science - Abstract
The Gcn5-related N-acetyltransferases (GNATs) are ubiquitously expressed in nature and perform a diverse range of cellular functions through the acetylation of small molecules and protein substrates. Using activated acetyl coenzyme A as a common acetyl donor, GNATs catalyse the transfer of an acetyl group to acceptor molecules including aminoglycoside antibiotics, glucosamine-6-phosphate, histones, serotonin and spermidine. There is often only very limited sequence conservation between members of the GNAT superfamily, in part, reflecting their capacity to bind a diverse array of substrates. In contrast, the secondary and tertiary structures are highly conserved, but then at the quaternary level there is further diversity, with GNATs shown to exist in monomeric, dimeric, or tetrameric states. Here we describe the X-ray crystallographic structure of a GNAT enzyme from Staphylococcus aureus with only low sequence identity to previously solved GNAT proteins. It contains many of the classical GNAT motifs, but lacks other hallmarks of the GNAT fold including the classic β-bulge splayed at the β-sheet interface. The protein is likely to be a dimer in solution based on analysis of the asymmetric unit within the crystal structure, homology with related GNAT family members, and size exclusion chromatography. The study provides the first high resolution structure of this enzyme, providing a strong platform for substrate and cofactor modelling, and structural/functional comparisons within this diverse enzyme superfamily.
- Published
- 2014
- Full Text
- View/download PDF
6. Structural characterisation of the nuclear import receptor importin alpha in complex with the bipartite NLS of Prp20.
- Author
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Noelia Roman, Mary Christie, Crystall M D Swarbrick, Bostjan Kobe, and Jade K Forwood
- Subjects
Medicine ,Science - Abstract
The translocation of macromolecules into the nucleus is a fundamental eukaryotic process, regulating gene expression, cell division and differentiation, but which is impaired in a range of significant diseases including cancer and viral infection. The import of proteins into the nucleus is generally initiated by a specific, high affinity interaction between nuclear localisation signals (NLSs) and nuclear import receptors in the cytoplasm, and terminated through the disassembly of these complexes in the nucleus. For classical NLSs (cNLSs), this import is mediated by the importin-α (IMPα) adaptor protein, which in turn binds to IMPβ to mediate translocation of nuclear cargo across the nuclear envelope. The interaction and disassembly of import receptor:cargo complexes is reliant on the differential localisation of nucleotide bound Ran across the envelope, maintained in its low affinity, GDP-bound form in the cytoplasm, and its high affinity, GTP-bound form in the nucleus. This in turn is maintained by the differential localisation of Ran regulating proteins, with RanGAP in the cytoplasm maintaining Ran in its GDP-bound form, and RanGEF (Prp20 in yeast) in the nucleus maintaining Ran in its GTP-bound form. Here, we describe the 2.1 Å resolution x-ray crystal structure of IMPα in complex with the NLS of Prp20. We observe 1,091 Å(2) of buried surface area mediated by an extensive array of contacts involving residues on armadillo repeats 2-7, utilising both the major and minor NLS binding sites of IMPα to contact bipartite NLS clusters (17)RAKKMSK(23) and (3)KR(4), respectively. One notable feature of the major site is the insertion of Prp20NLS Ala(18) between the P0 and P1 NLS sites, noted in only a few classical bipartite NLSs. This study provides a detailed account of the binding mechanism enabling Prp20 interaction with the nuclear import receptor, and additional new information for the interaction between IMPα and cargo.
- Published
- 2013
- Full Text
- View/download PDF
7. Explainable Learning Analytics to Identify Disengaged Students Early in Semester: An Intervention Supporting Widening Participation
- Author
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Kelly Linden, Neil van der Ploeg, and Noelia Roman
- Abstract
There is a small window of opportunity at the beginning of semester for a university to provide commencing students with timely and targeted support. However, there is limited information available on interventions that identify and support disengaged students from equity groups without using equity group status as the basis for the contact. The aim of this study was to use learning analytics that were explainable to the end users to identify and support commencing undergraduate students at an Australian regional university. Non-submission of an early assessment item accurately identified disengaged students and those students with successful dialogue with the Outreach Team were less likely to receive a failing grade. Analysis of intersectionality revealed that student progress rate decreased with additional equity factors. A holistic conversation with the Outreach Team increased retention for equity students the following semester, indicating that explainable learning analytics can be used to support equity students.
- Published
- 2023
- Full Text
- View/download PDF
8. Explainable learning analytics to identify disengaged students early in semester: an intervention supporting widening participation
- Author
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Kelly Linden, Neil van der Ploeg, and Noelia Roman
- Subjects
Public Administration ,Education - Published
- 2023
9. Developing a learning analytics resource with meaningful data for first year teachers
- Author
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Sarah Teakel, Kelly Linden, Neil Van der Ploeg, Noelia Roman, and Ben Hicks
- Abstract
It is known that due to the large, diverse sets of data captured in learning analytics, clear display of information is crucial to its success. Here, we describe a concise learning analytics resource, the Cohort Snapshot, that has been developed using a human centred approach, with input from experienced academics from across the institution. Meaningful data is presented as a unit level summary and includes program enrolment, student demographics, grade distributions and LMS activity. The data that was used to develop the resource was accessed via the university’s data warehouse which was synthesised using the R programming language. The Cohort Snapshot provides teaching academics, including sessional staff, access to data, to allow the adaption of teaching pedagogy to meet the needs of increasingly diverse student cohorts in a regional Australian university.
- Published
- 2022
10. Structural basis for nuclear import selectivity of pioneer transcription factor SOX2
- Author
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Megan R. Edwards, David A. Jans, Nicole Dominado, Christopher F. Basler, Bikshapathi Jagga, Jade K. Forwood, David Aragão, Shane Raidal, Gary R. Hime, Murray Stewart, Kylie M. Wagstaff, Jeffrey D. Nanson, Noelia Roman, Miriam Pagin, Silvia K. Nicolis, Jagga, B, Edwards, M, Pagin, M, Wagstaff, K, Aragão, D, Roman, N, Nanson, J, Raidal, S, Dominado, N, Stewart, M, Jans, D, Hime, G, Nicolis, S, Basler, C, and Forwood, J
- Subjects
Models, Molecular ,0301 basic medicine ,Cellular differentiation ,Nuclear Localization Signals ,General Physics and Astronomy ,Plasma protein binding ,Mice ,0302 clinical medicine ,Neural Stem Cells ,Protein Isoforms ,Multidisciplinary ,Protein subcellular localization prediction ,Cell biology ,Sox2, importins, nuclear localization, transcription factor ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Nuclear transport ,embryonic structures ,Drosophila ,biological phenomena, cell phenomena, and immunity ,Protein Binding ,Science ,Protein domain ,Active Transport, Cell Nucleus ,Biology ,Article ,General Biochemistry, Genetics and Molecular Biology ,Structure-Activity Relationship ,03 medical and health sciences ,Protein Domains ,stomatognathic system ,Transcription factors ,medicine ,Animals ,Humans ,Point Mutation ,Amino Acid Sequence ,Transcription factor ,X-ray crystallography ,Cell Nucleus ,SOXB1 Transcription Factors ,fungi ,General Chemistry ,Cell nucleus ,HEK293 Cells ,030104 developmental biology ,Mutant Proteins ,sense organs ,Nuclear localization sequence - Abstract
SOX (SRY-related HMG-box) transcription factors perform critical functions in development and cell differentiation. These roles depend on precise nuclear trafficking, with mutations in the nuclear targeting regions causing developmental diseases and a range of cancers. SOX protein nuclear localization is proposed to be mediated by two nuclear localization signals (NLSs) positioned within the extremities of the DNA-binding HMG-box domain and, although mutations within either cause disease, the mechanistic basis has remained unclear. Unexpectedly, we find here that these two distantly positioned NLSs of SOX2 contribute to a contiguous interface spanning 9 of the 10 ARM domains on the nuclear import adapter IMPα3. We identify key binding determinants and show this interface is critical for neural stem cell maintenance and for Drosophila development. Moreover, we identify a structural basis for the preference of SOX2 binding to IMPα3. In addition to defining the structural basis for SOX protein localization, these results provide a platform for understanding how mutations and post-translational modifications within these regions may modulate nuclear localization and result in clinical disease, and also how other proteins containing multiple NLSs may bind IMPα through an extended recognition interface., The SOX2 pioneer transcription factor performs critical roles in pluripotency and self-renewal of embryonic stem cells. Here the authors show that SOX2’s two nuclear localization signal sequences form a contiguous binding interface on the nuclear import receptor importin-α3, and provide a structural basis for the preference of SOX2 binding to IMPα3.
- Published
- 2021
11. Structural Basis for Regulation of the Human Acetyl-CoA Thioesterase 12 and Interactions with the Steroidogenic Acute Regulatory Protein-related Lipid Transfer (START) Domain
- Author
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Nathan Cowieson, Edward I Patterson, Crystall M.D. Swarbrick, Helena Berglund, Jeffrey D. Nanson, Marina I. Siponen, Lari Lehtiö, Noelia Roman, and Jade K. Forwood
- Subjects
Models, Molecular ,Protein Conformation ,Allosteric regulation ,Plasma protein binding ,Biology ,Crystallography, X-Ray ,Biochemistry ,chemistry.chemical_compound ,Protein structure ,Thioesterase ,Scattering, Small Angle ,Hydrolase ,Humans ,Binding site ,Molecular Biology ,Acetyl-CoA ,Cell Biology ,Phosphoproteins ,Lipids ,chemistry ,Regulatory sequence ,Protein Structure and Folding ,Chromatography, Gel ,Thiolester Hydrolases ,Protein Binding - Abstract
Acetyl-CoA plays a fundamental role in cell signaling and metabolic pathways, with its cellular levels tightly controlled through reciprocal regulation of enzymes that mediate its synthesis and catabolism. ACOT12, the primary acetyl-CoA thioesterase in the liver of human, mouse, and rat, is responsible for cleavage of the thioester bond within acetyl-CoA, producing acetate and coenzyme A for a range of cellular processes. The enzyme is regulated by ADP and ATP, which is believed to be mediated through the ligand-induced oligomerization of the thioesterase domains, whereby ATP induces active dimers and tetramers, whereas apo- and ADP-bound ACOT12 are monomeric and inactive. Here, using a range of structural and biophysical techniques, it is demonstrated that ACOT12 is a trimer rather than a tetramer and that neither ADP nor ATP exert their regulatory effects by altering the oligomeric status of the enzyme. Rather, the binding site and mechanism of ADP regulation have been determined to occur through two novel regulatory regions, one involving a large loop that links the thioesterase domains (Phe(154)-Thr(178)), defined here as RegLoop1, and a second region involving the C terminus of thioesterase domain 2 (Gln(304)-Gly(326)), designated RegLoop2. Mutagenesis confirmed that Arg(312) and Arg(313) are crucial for this mode of regulation, and novel interactions with the START domain are presented together with insights into domain swapping within eukaryotic thioesterases for substrate recognition. In summary, these experiments provide the first structural insights into the regulation of this enzyme family, revealing an alternate hypothesis likely to be conserved throughout evolution.
- Published
- 2014
12. Expression, purification, crystallization and preliminary X-ray analysis of the PaaI-like thioesterase SAV0944 from Staphylococcus aureus
- Author
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Noelia Roman, P. Srivastava, Yogesh B. Khandokar, Kate Smith, and Jade K. Forwood
- Subjects
Staphylococcus aureus ,Protein Conformation ,Coenzyme A ,Biophysics ,Biology ,Crystallography, X-Ray ,medicine.disease_cause ,Biochemistry ,law.invention ,chemistry.chemical_compound ,Bacterial Proteins ,Thioesterase ,Structural Biology ,law ,Hydrolase ,Sodium citrate ,Genetics ,medicine ,Molecular replacement ,Crystallization ,DNA Primers ,Base Sequence ,Esterases ,Toxic shock syndrome ,Condensed Matter Physics ,medicine.disease ,chemistry ,Crystallization Communications - Abstract
Staphylococcus aureus is the causative agent of many diseases, including meningitis, bacteraemia, pneumonia, food poisoning and toxic shock syndrome. Structural characterization of the PaaI-like thioesterase SAV0944 (SaPaaI) from S. aureus subsp. aureus Mu50 will aid in understanding its potential as a new therapeutic target by knowledge of its molecular details and cellular functions. Here, the recombinant expression, purification and crystallization of SaPaaI thioesterase from S. aureus are reported. This protein initially crystallized with the ligand coenzyme A using the hanging-drop vapour-diffusion technique with condition No. 40 of Crystal Screen from Hampton Research at 296 K. Optimal final conditions consisting of 24% PEG 4000, 100 mM sodium citrate pH 6.5, 12% 2-propanol gave single diffraction-quality crystals. These crystals diffracted to beyond 2 Å resolution at the Australian Synchrotron and belonged to space group P1211, with unit-cell parameters a = 44.05, b = 89.05, c = 60.74 Å, β = 100.5°. Initial structure determination and refinement gave an R factor and R free of 17.3 and 22.0%, respectively, confirming a positive solution in obtaining phases using molecular replacement.
- Published
- 2014
13. Novel Flavivirus Antiviral That Targets the Host Nuclear Transport Importin α/β1 Heterodimer
- Author
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Belinda Maher, David A. Jans, Sarah C. Atkinson, Noelia Roman, Chunxiao Wang, Natalie A. Borg, Johanna E. Fraser, Sundy N.Y. Yang, Kylie M. Wagstaff, and Jade K. Forwood
- Subjects
Models, Molecular ,alpha Karyopherins ,0301 basic medicine ,Indoles ,importins ,viruses ,Population ,Protein domain ,Active Transport, Cell Nucleus ,nuclear transport inhibitors ,Importin ,Dengue virus ,medicine.disease_cause ,Antiviral Agents ,Article ,Cell Line ,Inhibitory Concentration 50 ,03 medical and health sciences ,Phenols ,Protein Domains ,flavivirus ,medicine ,Animals ,education ,lcsh:QH301-705.5 ,Cell Nucleus ,education.field_of_study ,dengue virus ,030102 biochemistry & molecular biology ,biology ,Protein Stability ,Chemistry ,virus diseases ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,In vitro ,3. Good health ,Cell biology ,Flavivirus ,030104 developmental biology ,lcsh:Biology (General) ,Cell culture ,viral infection ,Protein Multimerization ,Nuclear transport - Abstract
Dengue virus (DENV) threatens almost 70% of the world&rsquo, s population, with effective vaccine or therapeutic currently available. A key contributor to infection is nuclear localisation in the infected cell of DENV nonstructural protein 5 (NS5) through the action of the host importin (IMP) &alpha, /&beta, 1 proteins. Here, we used a range of microscopic, virological and biochemical/biophysical approaches to show for the first time that the small molecule GW5074 has anti-DENV action through its novel ability to inhibit NS5&ndash, IMP&alpha, 1 interaction in vitro as well as NS5 nuclear localisation in infected cells. Strikingly, GW5074 not only inhibits IMP&alpha, binding to IMP&beta, 1, but can dissociate preformed IMP&alpha, 1 heterodimer, through targeting the IMP&alpha, armadillo (ARM) repeat domain to impact IMP&alpha, thermal stability and &alpha, helicity, as shown using analytical ultracentrifugation, thermostability analysis and circular dichroism measurements. Importantly, GW5074 has strong antiviral activity at low µ, M concentrations against not only DENV-2, but also zika virus and West Nile virus. This work highlights DENV NS5 nuclear targeting as a viable target for anti-flaviviral therapeutics.
- Published
- 2019
14. Crystallization of the flexible nuclear import receptor importin-β in the unliganded state
- Author
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Bostjan Kobe, Noelia Roman, Mary Marfori, Jade K. Forwood, and Brenda Kirkby
- Subjects
Saccharomyces cerevisiae Proteins ,Recombinant Fusion Proteins ,Molecular Sequence Data ,Statistics as Topic ,Active Transport, Cell Nucleus ,Biophysics ,Saccharomyces cerevisiae ,Importin ,Biology ,Biochemistry ,X-Ray Diffraction ,Structural Biology ,Scattering, Small Angle ,Escherichia coli ,Genetics ,Amino Acid Sequence ,Particle Size ,Nuclear pore ,Glutathione Transferase ,Cell Nucleus ,Data Collection ,Temperature ,food and beverages ,Hydrogen-Ion Concentration ,beta Karyopherins ,Condensed Matter Physics ,Crystallography ,Solubility ,Crystallization Communications ,Nucleocytoplasmic Transport ,Karyopherins ,Ran ,Beta Karyopherins ,Transformation, Bacterial ,Nucleoporin ,Nuclear transport ,Crystallization - Abstract
The transport of macromolecules across the nuclear envelope is an essential eukaryotic process that enables proteins such as transcription factors, polymerases and histones to gain access to the genetic material contained within the nucleus. Importin-beta plays a central role in the nucleocytoplasmic transport process, mediating nuclear import through a range of interactions with cytoplasmic, nuclear and nuclear pore proteins such as importin-alpha, Ran, nucleoporins and various cargo molecules. The unliganded form of the full-length yeast importin-beta has been expressed and crystallized. The crystals were obtained by vapour diffusion at pH 6.5 and 290 K. The crystals belonged to space group P2(1) (unit-cell parameters a = 58.17, b = 127.25, c = 68.52 A, beta = 102.23). One molecule is expected in the asymmetric unit. The crystals diffracted to 2.4 A resolution using a laboratory X-ray source and were suitable for crystal structure determination.
- Published
- 2009
15. Structural Characterization of a Gcn5-Related N-Acetyltransferase from Staphylococcus aureus
- Author
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Zainab Himiari, Yogesh B. Khandokar, Jade K. Forwood, Crystall M.D. Swarbrick, Noelia Roman, P. Srivastava, Subir Sarker, and Shane Raidal
- Subjects
Protein Folding ,Staphylococcus aureus ,Science ,Amino Acid Motifs ,Molecular Sequence Data ,Sequence alignment ,Biology ,Crystallography, X-Ray ,Biochemistry ,Protein structure ,Bacterial Proteins ,Transferases ,Acetyltransferases ,Escherichia coli ,Transferase ,Gnat ,Amino Acid Sequence ,Protein Structure, Quaternary ,Peptide sequence ,Multidisciplinary ,Biology and Life Sciences ,Proteins ,Enzymes ,Protein Structure, Tertiary ,Acetylation ,Enzymology ,Medicine ,Protein folding ,Dimerization ,Sequence Alignment ,Research Article - Abstract
The Gcn5-related N-acetyltransferases (GNATs) are ubiquitously expressed in nature and perform a diverse range of cellular functions through the acetylation of small molecules and protein substrates. Using activated acetyl coenzyme A as a common acetyl donor, GNATs catalyse the transfer of an acetyl group to acceptor molecules including aminoglycoside antibiotics, glucosamine-6-phosphate, histones, serotonin and spermidine. There is often only very limited sequence conservation between members of the GNAT superfamily, in part, reflecting their capacity to bind a diverse array of substrates. In contrast, the secondary and tertiary structures are highly conserved, but then at the quaternary level there is further diversity, with GNATs shown to exist in monomeric, dimeric, or tetrameric states. Here we describe the X-ray crystallographic structure of a GNAT enzyme from Staphylococcus aureus with only low sequence identity to previously solved GNAT proteins. It contains many of the classical GNAT motifs, but lacks other hallmarks of the GNAT fold including the classic β-bulge splayed at the β-sheet interface. The protein is likely to be a dimer in solution based on analysis of the asymmetric unit within the crystal structure, homology with related GNAT family members, and size exclusion chromatography. The study provides the first high resolution structure of this enzyme, providing a strong platform for substrate and cofactor modelling, and structural/functional comparisons within this diverse enzyme superfamily.
- Published
- 2014
16. Differential expression of two isolates of beak and feather disease virus capsid protein in Escherichia coli
- Author
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Edward I Patterson, Crystall M.D. Swarbrick, Shane Raidal, Jade K. Forwood, and Noelia Roman
- Subjects
Circovirus ,Antigenicity ,Molecular Sequence Data ,Cockatoos ,medicine.disease_cause ,Virus ,law.invention ,Microbiology ,Parrots ,law ,Virology ,Protein purification ,medicine ,Escherichia coli ,Animals ,Amino Acid Sequence ,Circoviridae Infections ,Cloning, Molecular ,Peptide sequence ,biology ,Bird Diseases ,biology.organism_classification ,Recombinant Proteins ,Cacatua tenuirostris ,Capsid ,Recombinant DNA ,Capsid Proteins - Abstract
Expression of recombinant beak and feather disease virus (BFDV) capsid-associated protein (Cap) has relied on inefficient techniques that typically produce low yields or use specialized expression systems, which greatly increase the cost and expertise required for mass production. An Escherichia coli system was used to express recombinant BFDV Cap derived from two isolates of BFDV, from a Long-billed Corella (Cacatua tenuirostris) and an Orange-bellied parrot (OBP; Neophema chrysogaster). Purification by affinity and size exclusion chromatography was optimized through an iterative process involving screening and modification of buffer constituents and pH. A buffer containing glycerol, β-mercaptoethanol, Triton X-100, and a high concentration of NaCl at pH 8 was used to increase solubility of the protein. The final concentration of the corella-isolated BFDV protein was fifteen- to twenty-fold greater than that produced in previous publications using E. coli expression systems. Immunoassays were used to confirm the specific antigenicity of recombinant Cap, verifying its validity for use in continued experimentation as a potential vaccine, a reagent in diagnostic assays, and as a concentrated sample for biological discoveries.
- Published
- 2012
17. Functional and structural properties of mammalian acyl-coenzyme A thioesterases
- Author
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Brenda Kirkby, Noelia Roman, Stuart Kellie, Jade K. Forwood, and Bostjan Kobe
- Subjects
Models, Molecular ,Protein Conformation ,Coenzyme A ,ACOT11 ,Biology ,Biochemistry ,Gene Expression Regulation, Enzymologic ,chemistry.chemical_compound ,Peroxisomes ,Animals ,Humans ,chemistry.chemical_classification ,Fatty acid metabolism ,Endoplasmic reticulum ,Fatty acid ,Cell Biology ,Peroxisome ,Lipid Metabolism ,Mitochondria ,Isoenzymes ,chemistry ,ACOT7 ,Arachidonic acid ,Acyl Coenzyme A ,Thiolester Hydrolases - Abstract
Acyl-coenzyme A thioesterases (Acots) play important cellular roles in mammalian fatty acid metabolism through modulation of cellular concentrations of activated fatty acyl-CoAs. Acots catalyse the hydrolysis of the thioester bond present within acyl-CoA ester molecules to yield coenzyme A (CoASH) and the corresponding non-esterified fatty acid. Acyl-CoA thioesterases are expressed ubiquitously in both prokaryotes and eukaryotes and, in higher order organisms, the enzymes are expressed and localised in a tissue-dependent manner within the cytosol, mitochondria, peroxisomes and endoplasmic reticulum. Recent studies have led to advances in the functional and structural characterization of many mammalian Acot family members. These include the structure determination of both type-I and type-II Acot family members, structural elucidation of the START domain of ACOT11, identification of roles in arachidonic acid and inflammatory prostaglandin production by Acot7, and inclusion of a 13th Acot family member. Here, we review and analyse the current literature on mammalian Acots with respect to their characterization and summarize the current knowledge on the structure, function and regulation of this enzyme family.
- Published
- 2010
18. Role of ACOT7 in Arachidonic Acid Production and Inflammation
- Author
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Crystall Swarbrick, Noelia Roman, Jade K. Forwood, Crystall Swarbrick, Noelia Roman, and Jade K. Forwood
- Published
- 2011
- Full Text
- View/download PDF
19. Assessment design in molecular pathology
- Author
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Sarah Milograna, wouter kalle, Noelia Roman, and Martin Pal
20. Delivering a Microbiology Subject in a Novel Intensive Course Model
- Author
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wouter kalle, Noelia Roman, and Thiru Vanniasinkam
21. Role of ACOT7 in Arachidonic Acid Production and Inflammation
- Author
-
Crystall M.D. Swarbrick, Jade K. Forwood, and Noelia Roman
- Subjects
chemistry.chemical_classification ,biology ,Endoplasmic reticulum ,Fatty acid ,Mitochondrion ,Peroxisome ,chemistry.chemical_compound ,Cytosol ,Enzyme ,Phospholipase A2 ,chemistry ,Biochemistry ,biology.protein ,Arachidonic acid - Abstract
Acyl-CoA Thioesterases (ACOTs) perform a wide range of cellular functions by catalysing the thiolytic cleavage of activated fatty acyl-CoAs. Substrates of ACOTs include short to long-chain acyl-CoAs as well as a range of methyl-branched, and dicarboxylic bile acidCoAs (M. C. Hunt & Alexson, 2008). Expression of ACOTs have been detected in both prokaryotes and eukaryotes with expression in higher organisms being detected in cytosol, mitochondria, peroxisomes and endoplasmic reticulum (J. Yamada, 2005). Within the ACOT enzyme family, one member in particular, ACOT7 has recently been identified as playing a role inflammation through the production of arachidonic acid (AA). It was recently proposed that ACOT7-mediated AA production may provide a complementary source of AA to the well characterised phospholipase A2 (PLA2) pathway (Satoru Sakuma, Usa, & Fujimoto, 2006); see Table 1 for review of Acot substrate specificity. Evidence for these observations was through experimental data showing that ACOT7 possessed high substrate specificity for AA-CoA; the gene encoding ACOT7 was highly expressed in macrophages and up-regulated when stimulated by lipopolysaccharide (LPS); and that over-expression of the enzyme lead to an increase in prostaglandin production. Together, these observations highlight a novel role of ACOT7 in inflammation through the production of arachidonic acid from the thiolytic cleavage of activated polyunsaturated omega-6 fatty acid C20:4-CoA (Forwood et al., 2007).
22. Teaching First: Professional Development for Sessional Regional Academics
- Author
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Noelia Roman, Kelly Linden, and Wood, Denise M.
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