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Kelly J, Vinogradov E, Robotham A, Tessier L, Logan SM, Jarrell KF. Characterizing the N- and O-linked glycans of the PGF-CTERM sorting domain-containing S-layer protein of Methanoculleus marisnigri. Glycobiology 2022; 32:629-644. [PMID: 35481895 DOI: 10.1093/glycob/cwac019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 01/05/2023] Open
Abstract
The glycosylation of structural proteins is a widespread posttranslational modification in Archaea. Although only a handful of archaeal N-glycan structures have been determined to date, it is evident that the diversity of structures expressed is greater than in the other domains of life. Here, we report on our investigation of the N- and O-glycan modifications expressed by Methanoculleus marisnigri, a mesophilic methanogen from the Order Methanomicrobiales. Unusually, mass spectrometry (MS) analysis of purified archaella revealed no evidence for N- or O-glycosylation of the constituent archaellins, In contrast, the S-layer protein, identified as a PGF-CTERM sorting domain-containing protein encoded by MEMAR_RS02690, is both N- and O-glycosylated. Two N-glycans were identified by NMR and MS analysis: a trisaccharide α-GlcNAc-4-β-GlcNAc3NGaAN-4-β-Glc-Asn where the second residue is 2-N-acetyl, 3-N-glyceryl-glucosamide and a disaccharide β-GlcNAc3NAcAN-4-β-Glc-Asn, where the terminal residue is 2,3 di-N-acetyl-glucosamide. The same trisaccharide was also found N-linked to a type IV pilin. The S-layer protein is also extensively modified in the threonine-rich region near the C-terminus with O-glycans composed exclusively of hexoses. While the S-layer protein has a predicted PGF-CTERM processing site, no evidence of a truncated and lipidated C-terminus, the expected product of processing by an archaeosortase, was found. Finally, NMR also identified a polysaccharide expressed by M. marisnigri and composed of a repeating tetrasaccharide unit of [-2-β-Ribf-3-α-Rha2OMe-3-α-Rha - 2-α-Rha-]. This is the first report of N- and O-glycosylation in an archaeon from the Order Methanomicrobiales.
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Affiliation(s)
- John Kelly
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Evgeny Vinogradov
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Anna Robotham
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Luc Tessier
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Susan M Logan
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Ken F Jarrell
- Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Kelly JF, Vinogradov E, Stupak J, Robotham AC, Logan SM, Berezuk A, Khursigara CM, Jarrell KF. Identification of a novel N-linked glycan on the archaellins and S-layer protein of the thermophilic methanogen, Methanothermococcus thermolithotrophicus. J Biol Chem 2020; 295:14618-14629. [PMID: 32817340 DOI: 10.1074/jbc.ra120.012790] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/28/2020] [Indexed: 01/25/2023] Open
Abstract
Motility in archaea is facilitated by a unique structure termed the archaellum. N-Glycosylation of the major structural proteins (archaellins) is important for their subsequent incorporation into the archaellum filament. The identity of some of these N-glycans has been determined, but archaea exhibit extensive variation in their glycans, meaning that further investigations can shed light not only on the specific details of archaellin structure and function, but also on archaeal glycobiology in general. Here we describe the structural characterization of the N-linked glycan modifications on the archaellins and S-layer protein of Methanothermococcus thermolithotrophicus, a methanogen that grows optimally at 65 °C. SDS-PAGE and MS analysis revealed that the sheared archaella are composed principally of two of the four predicted archaellins, FlaB1 and FlaB3, which are modified with a branched, heptameric glycan at all N-linked sequons except for the site closest to the N termini of both proteins. NMR analysis of the purified glycan determined the structure to be α-d-glycero-d-manno-Hep3OMe6OMe-(1-3)-[α-GalNAcA3OMe-(1-2)-]-β-Man-(1-4)-[β-GalA3OMe4OAc6CMe-(1-4)-α-GalA-(1-2)-]-α-GalAN-(1-3)-β-GalNAc-Asn. A detailed investigation by hydrophilic interaction liquid ion chromatography-MS discovered the presence of several, less abundant glycan variants, related to but distinct from the main heptameric glycan. In addition, we confirmed that the S-layer protein is modified with the same heptameric glycan, suggesting a common N-glycosylation pathway. The M. thermolithotrophicus archaellin N-linked glycan is larger and more complex than those previously identified on the archaellins of related mesophilic methanogens, Methanococcus voltae and Methanococcus maripaludis This could indicate that the nature of the glycan modification may have a role to play in maintaining stability at elevated temperatures.
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Affiliation(s)
- John F Kelly
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada.
| | - Evgeny Vinogradov
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Jacek Stupak
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Anna C Robotham
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Susan M Logan
- Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Alison Berezuk
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Cezar M Khursigara
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
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Cox AD, St Michael F, Aubry A, Strong PCR, Hayes AC, Logan SM. Comparison of polysaccharide glycoconjugates as candidate vaccines to combat Clostridiodes (Clostridium) difficile. Glycoconj J 2020; 38:493-508. [PMID: 32789783 DOI: 10.1007/s10719-020-09937-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 07/06/2020] [Accepted: 07/23/2020] [Indexed: 10/23/2022]
Abstract
Two known Clostridiodes (Clostridium) difficile surface antigens, a lipoteichoic acid (LTA) and a polysaccharide (PS-II) were isolated and purified in order to prepare glycoconjugate vaccines to the carrier protein human serum albumin utilising a reductive amination strategy. Mice and rabbits were immunized with a prime and two boost strategy and the resulting sera were examined for their ability to recognise the purified homologous antigens and subsequently killed whole cells of C. difficile strains and other Clostridia species. Immunisation derived antisera from rabbits and mice, recognised all strains of C. difficile vegetative cells examined, with generally similar titers from animals that received the LTA or the PS-II conjugates. Sera raised to the LTA conjugates were able to recognise other Clostridia species C. butyricum, C. bifermentans and C. subterminale whereas sera raised to the PS-II conjugates were not. These LTA and PS-II sera recognised live cells in an immunofluorescence assay and were also able to recognise the spore form of the bacterium. This study has confirmed that the LTA and PS-II polysaccharides are both highly conserved surface polymers of C. difficile that are easily accessible to the immune system and as such may have potential as vaccine antigens or as targets for therapeutics to combat C. difficile infection.
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Affiliation(s)
- A D Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada.
| | - F St Michael
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
| | - A Aubry
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
| | - P C R Strong
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
| | - A C Hayes
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
| | - S M Logan
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, K1A 0R6, Canada
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Cairns CM, van Faassen H, St. Michael F, Aubry A, Henry KA, Rossotti MA, Logan SM, Hussack G, Gisch N, Hogendorf WFJ, Pedersen CM, Cox AD. Development and Characterization of Mouse Monoclonal Antibodies Specific for Clostridiodes (Clostridium) difficile Lipoteichoic Acid. ACS Chem Biol 2020; 15:1050-1058. [PMID: 32191024 DOI: 10.1021/acschembio.0c00066] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Clostridiodes (Clostridium) difficile is an anaerobic Gram-positive, spore-forming nosocomial, gastrointestinal pathogen causing C. difficile-associated disease with symptoms ranging from mild cases of antibiotic-associated diarrhea to fatal pseudomembranous colitis. We developed murine monoclonal antibodies (mAbs) specific for a conserved cell surface antigen, lipoteichoic acid (LTA)of C. difficile. The mAbs were characterized in terms of their thermal stability, solubility, and their binding to LTA by surface plasmon resonance and competitive ELISA. Synthetic LTA molecules were prepared in order to better define the minimum epitope required to mimic the natural antigen, and three repeat units of the polymer were required for optimal recognition. One of the murine mAbs was chimerized with human constant region domains and was found to recognize the target antigen identically to the mouse version. These mAbs may be useful as therapeutics (standalone, in conjunction with known antitoxin approaches, or as delivery vehicles for antibody drug conjugates targeting the bacterium), as diagnostic agents, and in infection control applications.
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Affiliation(s)
- Chantelle M. Cairns
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Henk van Faassen
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Frank St. Michael
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Annie Aubry
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Kevin A. Henry
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Martin A. Rossotti
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Susan M. Logan
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Greg Hussack
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | | | | | - Andrew D. Cox
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
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Liu M, Zhong Y, Chen J, Liu Y, Tang C, Wang X, Zhang Y, Wang P, Logan SM, Chen W, Wei B. Oral immunization of mice with a multivalent therapeutic subunit vaccine protects against Helicobacter pylori infection. Vaccine 2020; 38:3031-3041. [PMID: 32139315 DOI: 10.1016/j.vaccine.2020.02.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 02/10/2020] [Accepted: 02/12/2020] [Indexed: 02/08/2023]
Abstract
Helicobacter pylori is a human class I carcinogen and no effective prophylactic or therapeutic H. pylori vaccine has yet been marketed. H. pylori can escape the host immune response, but the precise immune protection mechanisms in humans remain unknown. In this study, we developed a multivalent, subunit H. pylori vaccine candidate by formulating three commonly used H. pylori antigens, neutrophil-activating protein (NAP), urease subunit A (UreA) and subunit B (UreB) with the mucosal adjuvant, a double-mutant heat-labile toxin (dmLT) from Escherichia coli, and evaluated its immunogenicity and therapeutic efficacy in a mouse model of H. pylori infection. We found that oral immunization of H. pylori-infected mice significantly reduced gastric bacterial colonization at both 2 and 8 weeks after immunization. The reduction in bacterial burdens was accompanied with significantly increased serum antigen-specific IgG responses and mucosal IgA responses. Moreover, oral immunization also induced Th1/Th17 immune responses, which may play a synergistic role with the specific antibodies in the elimination of H. pylori. Thus, our vaccine candidate appears able to overcome the immune evasion mechanism of H. pylori, restore the suppression of Th2 immune responses with the induction of a strong humoral immune response. These results lay the foundation for the development of an optimized oral therapeutic H. pylori vaccine with increased immunogenicity of UreA and UreB, as well as providing long-term immunity.
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Affiliation(s)
- Meiying Liu
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Youxiu Zhong
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Jing Chen
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Yu Liu
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Chongfa Tang
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Xuewei Wang
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Yanbin Zhang
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Ping Wang
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China
| | - Susan M Logan
- Human Health Therapeutics (HHT) Research Center, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
| | - Wangxue Chen
- Human Health Therapeutics (HHT) Research Center, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada.
| | - Bo Wei
- National Vaccine and Serum Institute (NVSI), 38 Jinghai 2nd Road, Beijing Economic and Technological Development Zone, Beijing, China.
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Aubry A, Zou W, Vinogradov E, Williams D, Chen W, Harris G, Zhou H, Schur MJ, Gilbert M, Douce GR, Logan SM. In vitro Production and Immunogenicity of a Clostridium Difficile Spore-Specific BclA3 Glycopeptide Conjugate Vaccine. Vaccines (Basel) 2020; 8:vaccines8010073. [PMID: 32046000 PMCID: PMC7157674 DOI: 10.3390/vaccines8010073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 02/06/2023] Open
Abstract
Abstract: The BclA3 glycoprotein is a major component of the exosporangial layer of Clostridium difficile spores and in this study we demonstrate that this glycoprotein is a major spore surface associated antigen. Here, we confirm the role of SgtA glycosyltransferase (SgtA GT) in BclA3 glycosylation and recapitulate this process by expressing and purifying SgtA GT fused to MalE, the maltose binding protein from Escherichia coli. In vitro assays using the recombinant enzyme and BclA3 synthetic peptides demonstrated that SgtA GT was responsible for the addition of β-O-linked GlcNAc to threonine residues of each synthetic peptide. These peptide sequences were selected from the central, collagen repeat region of the BclA3 protein. Following optimization of SgtA GT activity, we generated sufficient glycopeptide (10 mg) to allow conjugation to KLH (keyhole limpet hemocyanin) protein. Glycosylated and unglycosylated versions of these conjugates were then used as antigens to immunize rabbits and mice. Immune responses to each of the conjugates were examined by Enzyme Linked Immunosorbent Assay ELISA. Additionally, the BclA3 conjugated peptide and glycopeptide were used as antigens in an ELISA assay with serum raised against formalin-killed spores. Only the glycopeptide was recognized by anti-spore polyclonal immune serum demonstrating that the glycan moiety is a predominant spore-associated surface antigen. To determine whether antibodies to these peptides could modify persistence of spores within the gut, animals immunized intranasally with either the KLH-glycopeptide or KLH-peptide conjugate in the presence of cholera toxin, were challenged with R20291 spores. Although specific antibodies were raised to both antigens, immunization did not provide any protection against acute or recurrent disease.
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Affiliation(s)
- Annie Aubry
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Wei Zou
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Evguenii Vinogradov
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Dean Williams
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Wangxue Chen
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Greg Harris
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Hongyan Zhou
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Melissa J. Schur
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Michel Gilbert
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
| | - Gillian R. Douce
- Institute of Infection, Immunity, Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland, UK;
| | - Susan M. Logan
- Vaccine Program, Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; (A.A.); (W.Z.); (E.V.); (D.W.); (W.C.); (G.H.); (H.Z.); (M.J.S.); (M.G.)
- Correspondence: ; Tel.: +613-990-0839
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Hodgins MJ, Filiatreault S, Keeping‐Burke L, Logan SM. Patterns of patient coping following hospital discharge from medical and surgical units: A pilot study. Nurs Health Sci 2019; 22:118-125. [DOI: 10.1111/nhs.12658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 08/26/2019] [Accepted: 09/18/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Marilyn J. Hodgins
- Faculty of NursingUniversity of New Brunswick (UNB) Fredericton Fredericton Canada
| | - Sarah Filiatreault
- Faculty of NursingUniversity of New Brunswick (UNB) Fredericton Fredericton Canada
| | - Lisa Keeping‐Burke
- Department of Nursing & Health SciencesUniversity of New Brunswick Saint John Saint John Canada
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Ivarsson ME, Durantie E, Huberli C, Huwiler S, Hegde C, Friedman J, Altamura F, Lu J, Verdu EF, Bercik P, Logan SM, Chen W, Leroux JC, Castagner B. Small-Molecule Allosteric Triggers of Clostridium difficile Toxin B Auto-proteolysis as a Therapeutic Strategy. Cell Chem Biol 2019; 26:17-26.e13. [DOI: 10.1016/j.chembiol.2018.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 06/27/2018] [Accepted: 09/28/2018] [Indexed: 01/19/2023]
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Richards E, Bouché L, Panico M, Arbeloa A, Vinogradov E, Morris H, Wren B, Logan SM, Dell A, Fairweather NF. The S-layer protein of a Clostridium difficile SLCT-11 strain displays a complex glycan required for normal cell growth and morphology. J Biol Chem 2018; 293:18123-18137. [PMID: 30275012 PMCID: PMC6254364 DOI: 10.1074/jbc.ra118.004530] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/27/2018] [Indexed: 12/16/2022] Open
Abstract
Clostridium difficile is a bacterial pathogen that causes major health challenges worldwide. It has a well-characterized surface (S)-layer, a para-crystalline proteinaceous layer surrounding the cell wall. In many bacterial and archaeal species, the S-layer is glycosylated, but no such modifications have been demonstrated in C. difficile. Here, we show that a C. difficile strain of S-layer cassette type 11, Ox247, has a complex glycan attached via an O-linkage to Thr-38 of the S-layer low-molecular-weight subunit. Using MS and NMR, we fully characterized this glycan. We present evidence that it is composed of three domains: (i) a core peptide-linked tetrasaccharide with the sequence -4-α-Rha-3-α-Rha-3-α-Rha-3-β-Gal-peptide; (ii) a repeating pentasaccharide with the sequence -4-β-Rha-4-α-Glc-3-β-Rha-4-(α-Rib-3-)β-Rha-; and (iii) a nonreducing end-terminal 2,3 cyclophosphoryl-rhamnose attached to a ribose-branched sub-terminal rhamnose residue. The Ox247 genome contains a 24-kb locus containing genes for synthesis and protein attachment of this glycan. Mutations in genes within this locus altered or completely abrogated formation of this glycan, and their phenotypes suggested that this S-layer modification may affect sporulation, cell length, and biofilm formation of C. difficile In summary, our findings indicate that the S-layer protein of SLCT-11 strains displays a complex glycan and suggest that this glycan is required for C. difficile sporulation and control of cell shape, a discovery with implications for the development of antimicrobials targeting the S-layer.
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Affiliation(s)
- Emma Richards
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Laura Bouché
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Maria Panico
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Ana Arbeloa
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom
| | - Evgeny Vinogradov
- the Vaccine Program, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Howard Morris
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,; Biopharmaspec, Suite 3.1, Lido Medical Centre, St. Saviours Road, JE2 7LA Jersey, United Kingdom, and
| | - Brendan Wren
- the London School of Hygiene and Tropical Medicine, WC1E 7HT, London, United Kingdom
| | - Susan M Logan
- the Vaccine Program, Human Health Therapeutics Research Centre, National Research Council, Ottawa, Ontario K1A 0R6, Canada
| | - Anne Dell
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,.
| | - Neil F Fairweather
- From the Department of Life Sciences, Imperial College London, SW7 2AZ London, United Kingdom,.
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10
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Hodgins MJ, Logan SM, Fraser JM, Buck DM, Stack BD. Clinical utility of scores on the Blaylock Risk Assessment Screen (BRASS): An analysis of administrative data. Appl Nurs Res 2018; 41:36-40. [PMID: 29853211 DOI: 10.1016/j.apnr.2018.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 02/07/2018] [Accepted: 03/02/2018] [Indexed: 12/01/2022]
Abstract
PURPOSE Project was undertaken to examine the utility of the Blaylock Risk Assessment Screen (BRASS) in identifying patients who may experience discharge complications as indicated by longer hospital stays or readmission within 30-days of a discharge to home. BACKGROUND Before measures can be put in place to facilitate discharge planning and to prevent unplanned readmission by recently discharged patients, those at risk of such events must be identified. METHODS Project involved an analysis of 13-months of administrative data from one tertiary care hospital. Utility of the BRASS was examined in terms of its sensitivity and specificity as well as its positive and negative predictive values. RESULTS Majority (83%) of hospital discharges were to home. Approximately 7% of patients experienced at least one readmission within 30-days of being discharged to home. Using scores of 10 or higher as an indicator of risk, BRASS exhibited a high degree of specificity suggesting it is useful for 'ruling in' those who have the outcomes-of-interest. However low sensitivity indicates many who experienced the outcomes were incorrectly classified by the BRASS as low risk. The low positive predictive value for 30-day readmission also suggests many who were classified by the BRASS as being 'at risk' were not readmitted. CONCLUSION The observed rate of 30-day readmission is likely conservative as the analysis involved data from only one acute care facility. One explanation for the low positive predictive value for 30-day readmission is that completion of the BRASS on admission enabled the implementation of preventive measures.
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Affiliation(s)
- Marilyn J Hodgins
- Faculty of Nursing, University of New Brunswick Fredericton, 208 MacLaggan Hall, 33 Dineen Drive, Fredericton, New Brunswick E3B 5A3, Canada.
| | | | | | | | - Bridget D Stack
- SJRH Family & Internal Medicine, and Palliative Care, Canada
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11
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Abstract
Cell surface polysaccharides produced by C. perfringens ATCC 13124 were analyzed using NMR, chemical and immunological methods. Two distinct polymers were identified. The more abundant PS1 had a structure based on a polymer of β-mannosamine with a number of modifications, including varying levels of substitution at O-6 with PEtN, N-acetylation, and different linkages between monosaccharides. The shortest variant of PS1 represented a lipoteichoic acid. It contained only 1-4-linkages between ManNAc residues, minor branching α-Ribf, and glucosyl-glycerol at the reducing end, which was acylated with linear saturated fatty acids C16, C18, and C20 (dominant). Other non-lipidated variants of PS1 contained less PEtN, no α-Ribf, up to 50% 1-3-linkages, and up to 25% ManN with the free amino group. The minor polysaccharide PS2 had a linear regular structure with a -4-α-Rha-3-β-Gal-4-β-GalNAc3PCho- repeating unit, where PCho indicates phosphocholine.
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Affiliation(s)
- Evgeny Vinogradov
- National Research Council of Canada, Vaccine Program, Human Health Therapeutics, Ottawa Canada, K1A OR6.
| | - Annie Aubry
- National Research Council of Canada, Vaccine Program, Human Health Therapeutics, Ottawa Canada, K1A OR6
| | - Susan M Logan
- National Research Council of Canada, Vaccine Program, Human Health Therapeutics, Ottawa Canada, K1A OR6
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12
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Kurniyati K, Kelly JF, Vinogradov E, Robotham A, Tu Y, Wang J, Liu J, Logan SM, Li C. A novel glycan modifies the flagellar filament proteins of the oral bacterium Treponema denticola. Mol Microbiol 2016; 103:67-85. [PMID: 27696564 DOI: 10.1111/mmi.13544] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2016] [Indexed: 01/12/2023]
Abstract
While protein glycosylation has been reported in several spirochetes including the syphilis bacterium Treponema pallidum and Lyme disease pathogen Borrelia burgdorferi, the pertinent glycan structures and their roles remain uncharacterized. Herein, a novel glycan with an unusual chemical composition and structure in the oral spirochete Treponema denticola, a keystone pathogen of periodontitis was reported. The identified glycan of mass 450.2 Da is composed of a monoacetylated nonulosonic acid (Non) with a novel extended N7 acyl modification, a 2-methoxy-4,5,6-trihydroxy-hexanoyl residue in which the Non has a pseudaminic acid configuration (L-glycero-L-manno) and is β-linked to serine or threonine residues. This novel glycan modifies the flagellin proteins (FlaBs) of T. denticola by O-linkage at multiple sites near the D1 domain, a highly conserved region of bacterial flagellins that interact with Toll-like receptor 5. Furthermore, mutagenesis studies demonstrate that the glycosylation plays an essential role in the flagellar assembly and motility of T. denticola. To our knowledge, this novel glycan and its unique modification sites have not been reported previously in any bacteria.
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Affiliation(s)
- Kurni Kurniyati
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA
| | - John F Kelly
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Evgeny Vinogradov
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Anna Robotham
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Youbing Tu
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA
| | - Juyu Wang
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, TX, 77030, USA
| | - Jun Liu
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, TX, 77030, USA
| | - Susan M Logan
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Chunhao Li
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA.,Department of Microbiology and Immunology, The State University of New York at Buffalo, New York, NY, 14214, USA
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13
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Bouché L, Panico M, Hitchen P, Binet D, Sastre F, Faulds-Pain A, Valiente E, Vinogradov E, Aubry A, Fulton K, Twine S, Logan SM, Wren BW, Dell A, Morris HR. The Type B Flagellin of Hypervirulent Clostridium difficile Is Modified with Novel Sulfonated Peptidylamido-glycans. J Biol Chem 2016; 291:25439-25449. [PMID: 27758867 PMCID: PMC5207245 DOI: 10.1074/jbc.m116.749481] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/12/2016] [Indexed: 01/15/2023] Open
Abstract
Glycosylation of flagellins is a well recognized property of many bacterial species. In this study, we describe the structural characterization of novel flagellar glycans from a number of hypervirulent strains of C. difficile. We used mass spectrometry (nano-LC-MS and MS/MS analysis) to identify a number of putative glycopeptides that carried a variety of glycoform substitutions, each of which was linked through an initial N-acetylhexosamine residue to Ser or Thr. Detailed analysis of a LLDGSSTEIR glycopeptide released by tryptic digestion, which carried two variant structures, revealed that the glycopeptide contained, in addition to carbohydrate moieties, a novel structural entity. A variety of electrospray-MS strategies using Q-TOF technology were used to define this entity, including positive and negative ion collisionally activated decomposition MS/MS, which produced unique fragmentation patterns, and high resolution accurate mass measurement to allow derivation of atomic compositions, leading to the suggestion of a taurine-containing peptidylamido-glycan structure. Finally, NMR analysis of flagellin glycopeptides provided complementary information. The glycan portion of the modification was assigned as α-Fuc3N-(1→3)-α-Rha-(1→2)-α-Rha3OMe-(1→3)-β-GlcNAc-(1→)Ser, and the novel capping moiety was shown to be comprised of taurine, alanine, and glycine. This is the first report of a novel O-linked sulfonated peptidylamido-glycan moiety decorating a flagellin protein.
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Affiliation(s)
- Laura Bouché
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Maria Panico
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Paul Hitchen
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Daniel Binet
- BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey JE2 7LA, United Kingdom
| | - Federico Sastre
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Alexandra Faulds-Pain
- the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Esmeralda Valiente
- the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Evgeny Vinogradov
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Annie Aubry
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Kelly Fulton
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Susan Twine
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Susan M Logan
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Brendan W Wren
- the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Anne Dell
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom,
| | - Howard R Morris
- From the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.,BioPharmaSpec, Suite 3.1 Lido Medical Centre, St. Saviours Road, Jersey JE2 7LA, United Kingdom
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14
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Valiente E, Bouché L, Hitchen P, Faulds-Pain A, Songane M, Dawson LF, Donahue E, Stabler RA, Panico M, Morris HR, Bajaj-Elliott M, Logan SM, Dell A, Wren BW. Role of Glycosyltransferases Modifying Type B Flagellin of Emerging Hypervirulent Clostridium difficile Lineages and Their Impact on Motility and Biofilm Formation. J Biol Chem 2016; 291:25450-25461. [PMID: 27703012 PMCID: PMC5207246 DOI: 10.1074/jbc.m116.749523] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/27/2016] [Indexed: 01/05/2023] Open
Abstract
Clostridium difficile is the principal cause of nosocomial infectious diarrhea worldwide. The pathogen modifies its flagellin with either a type A or type B O-linked glycosylation system, which has a contributory role in pathogenesis. We study the functional role of glycosyltransferases modifying type B flagellin in the 023 and 027 hypervirulent C. difficile lineages by mutagenesis of five putative glycosyltransferases and biosynthetic genes. We reveal their roles in the biosynthesis of the flagellin glycan chain and demonstrate that flagellar post-translational modification affects motility and adhesion-related bacterial properties of these strains. We show that the glycosyltransferases 1 and 2 (GT1 and GT2) are responsible for the sequential addition of a GlcNAc and two rhamnoses, respectively, and that GT3 is associated with the incorporation of a novel sulfonated peptidyl-amido sugar moiety whose structure is reported in our accompanying paper (Bouché, L., Panico, M., Hitchen, P., Binet, D., Sastre, F., Faulds-Pain, A., Valiente, E., Vinogradov, E., Aubry, A., Fulton, K., Twine, S., Logan, S. M., Wren, B. W., Dell, A., and Morris, H. R. (2016) J. Biol. Chem. 291, 25439–25449). GT2 is also responsible for methylation of the rhamnoses. Whereas type B modification is not required for flagellar assembly, some mutations that result in truncation or abolition of the glycan reduce bacterial motility and promote autoaggregation and biofilm formation. The complete lack of flagellin modification also significantly reduces adhesion of C. difficile to Caco-2 intestinal epithelial cells but does not affect activation of human TLR5. Our study advances our understanding of the genes involved in flagellar glycosylation and their biological roles in emerging hypervirulent C. difficile strains.
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Affiliation(s)
- Esmeralda Valiente
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Laura Bouché
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Paul Hitchen
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Alexandra Faulds-Pain
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Mario Songane
- the Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Lisa F Dawson
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Elizabeth Donahue
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Richard A Stabler
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Maria Panico
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Howard R Morris
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.,BioPharmaSpec Ltd., Suite 3.1, Lido Medical Centre, St. Saviours Road, Jersey JE2 7LA, United Kingdom
| | - Mona Bajaj-Elliott
- the Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, United Kingdom
| | - Susan M Logan
- the Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Ontario K1A 0R6, Canada, and
| | - Anne Dell
- the Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Brendan W Wren
- From the Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom,
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15
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Ding Y, Jones GM, Brimacombe C, Uchida K, Aizawa SI, Logan SM, Kelly JF, Jarrell KF. Identification of a gene involved in the biosynthesis pathway of the terminal sugar of the archaellin N-linked tetrasaccharide in Methanococcus maripaludis. Antonie Van Leeuwenhoek 2015; 109:131-48. [PMID: 26590834 DOI: 10.1007/s10482-015-0615-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/28/2015] [Indexed: 10/22/2022]
Abstract
In Methanococcus maripaludis, the three archaellins which comprise the archaellum are modified at multiple sites with an N-linked tetrasaccharide with the structure of Sug-4-β-ManNAc3NAmA6Thr-4-β-GlcNAc3NAcA-3-β-GalNAc, where Sug is a unique sugar (5S)-2-acetamido-2,4-dideoxy-5-O-methyl-L-erythro-hexos-5-ulo-1,5-pyranose, so far found exclusively in this species. In this study, a six-gene cluster mmp1089-1094, neighboring one of the genomic regions already known to contain genes involved with the archaellin N-glycosylation pathway, was examined for its potential involvement in the archaellin N-glycosylation or sugar biosynthesis pathway. The co-transcription of these six genes was demonstrated by RT-PCR. Mutants carrying an in-frame deletion in mmp1090, mmp1091 or mmp1092 were successfully generated. The Δmmp1090 deletion mutant was archaellated when examined by electron microscopy and mass spectrometry analysis of purified archaella showed that the archaellins were modified with a truncated N-glycan in which the terminal sugar residue and the threonine linked to the third sugar residue were missing. Both gene annotation and bioinformatic analyses indicate that MMP1090 is a UDP-glucose 4-epimerase, suggesting that the unique terminal sugar of the archaellin N-glycan might be synthesised from UDP-glucose or UDP-N-acetylglucosamine with an essential early step in synthesis catalysed by MMP1090. In contrast, no detectable phenotype related to archaellin glycosylation was observed in mutants deleted for either mmp1091 or mmp1092 while attempts to delete mmp1089, mmp1093 and mmp1094 were unsuccessful. Based on its demonstrated involvement in the archaellin N-glycosylation pathway, we designated mmp1090 as aglW.
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Affiliation(s)
- Yan Ding
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, K7L 3N6, Canada
| | - Gareth M Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, K7L 3N6, Canada
| | - Cedric Brimacombe
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, K7L 3N6, Canada
| | - Kaoru Uchida
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, 727-0023, Japan
| | - Shin-Ichi Aizawa
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, 727-0023, Japan
| | - Susan M Logan
- Human Health Therapeutics Portfolio, National Research Council, Ottawa, K1A 0R6, Canada
| | - John F Kelly
- Human Health Therapeutics Portfolio, National Research Council, Ottawa, K1A 0R6, Canada.
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, K7L 3N6, Canada.
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16
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Faulds-Pain A, Twine SM, Vinogradov E, Strong PCR, Dell A, Buckley AM, Douce GR, Valiente E, Logan SM, Wren BW. The post-translational modification of the Clostridium difficile flagellin affects motility, cell surface properties and virulence. Mol Microbiol 2014; 94:272-89. [PMID: 25135277 PMCID: PMC4441256 DOI: 10.1111/mmi.12755] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2014] [Indexed: 01/05/2023]
Abstract
Clostridium difficile is a prominent nosocomial pathogen, proliferating and causing enteric disease in individuals with a compromised gut microflora. We characterized the post-translational modification of flagellin in C. difficile 630. The structure of the modification was solved by nuclear magnetic resonance and shown to contain an N-acetylglucosamine substituted with a phosphorylated N-methyl-l-threonine. A reverse genetics approach investigated the function of the putative four-gene modification locus. All mutants were found to have truncated glycan structures by LC-MS/MS, taking into account bioinformatic analysis, we propose that the open reading frame CD0241 encodes a kinase involved in the transfer of the phosphate to the threonine, the CD0242 protein catalyses the addition of the phosphothreonine to the N-acetylglucosamine moiety and CD0243 transfers the methyl group to the threonine. Some mutations affected motility and caused cells to aggregate to each other and abiotic surfaces. Altering the structure of the flagellin modification impacted on colonization and disease recurrence in a murine model of infection, showing that alterations in the surface architecture of C. difficile vegetative cells can play a significant role in disease. We show that motility is not a requirement for colonization, but that colonization was compromised when the glycan structure was incomplete.
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17
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Hodgins MJ, Logan SM, Price K, Thompson C. Trials, tribulations, and triumphs of a pilot initiative to optimize the management of wounds complicated by diabetes within the home. Home Health Care Serv Q 2014; 33:89-105. [PMID: 24702637 DOI: 10.1080/01621424.2014.907553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
To support home health care nurses in their efforts to optimize the management of patients with wounds complicated by diabetes, an initiative was introduced that incorporated a standardized assessment tool, electronic data entry, and the provision of written treatment recommendations with supporting rationale prepared by nurses with expertise in diabetes and wound care. A pilot study was conducted that provided preliminary evidence of the feasibility of this initiative as well as its potential effect on outcomes for patients, nurses, and the home care program.
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Affiliation(s)
- Marilyn J Hodgins
- a University of New Brunswick , Fredericton , New Brunswick , Canada
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18
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Riazi A, Strong PCR, Coleman R, Chen W, Hirama T, van Faassen H, Henry M, Logan SM, Szymanski CM, MacKenzie R, Ghahroudi MA. Pentavalent single-domain antibodies reduce Campylobacter jejuni motility and colonization in chickens. PLoS One 2013; 8:e83928. [PMID: 24391847 PMCID: PMC3877120 DOI: 10.1371/journal.pone.0083928] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 11/08/2013] [Indexed: 11/18/2022] Open
Abstract
Campylobacter jejuni is the leading cause of bacterial foodborne illness in the world, with symptoms ranging from acute diarrhea to severe neurological disorders. Contaminated poultry meat is a major source of C. jejuni infection, and therefore, strategies to reduce this organism in poultry, are expected to reduce the incidence of Campylobacter-associated diseases. We have investigated whether oral administration of C. jejuni-specific single-domain antibodies would reduce bacterial colonization levels in chickens. Llama single-domain antibodies specific for C. jejuni were isolated from a phage display library generated from the heavy chain IgG variable domain repertoire of a llama immunized with C. jejuni flagella. Two flagella-specific single-domain antibodies were pentamerized to yield high avidity antibodies capable of multivalent binding to the target antigen. When administered orally to C. jejuni-infected two-day old chicks, the pentabodies significantly reduced C. jejuni colonization in the ceca. In vitro, the motility of the bacteria was also reduced in the presence of the flagella-specific pentabodies, suggesting the mechanism of action is through either direct interference with flagellar motility or antibody-mediated aggregation. Fluorescent microscopy and Western blot analyses revealed specific binding of the anti-flagella pentabodies to the C. jejuni flagellin.
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Affiliation(s)
- Ali Riazi
- AbCelex Technologies Inc., Toronto, Ontario, Canada
| | - Philippa C. R. Strong
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Russell Coleman
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Wangxue Chen
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Tomoko Hirama
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Henk van Faassen
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Matthew Henry
- Dow AgroSciences, Indianapolis, Indiana, United States of America
| | - Susan M. Logan
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Christine M. Szymanski
- Centennial Centre for Interdisciplinary Science, Department of Biological Sciences and Alberta Glycomics Centre, The University of Alberta, Edmonton, Alberta, Canada
| | - Roger MacKenzie
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
- Centennial Centre for Interdisciplinary Science, Department of Biological Sciences and Alberta Glycomics Centre, The University of Alberta, Edmonton, Alberta, Canada
| | - Mehdi Arbabi Ghahroudi
- Human Health Therapeutics, National Research Council of Canada, Ottawa, Ontario, Canada
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
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19
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Gutelius D, Hokeness K, Logan SM, Reid CW. Functional analysis of SleC from Clostridium difficile: an essential lytic transglycosylase involved in spore germination. Microbiology (Reading) 2013; 160:209-216. [PMID: 24140647 DOI: 10.1099/mic.0.072454-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Clostridium difficile is the most common cause of enteric disease and presents a major burden on healthcare systems globally due in part to the observed rapid rise in antibiotic resistance. The ability of C. difficile to form endospores is a key feature in the organism's pathogenesis and transmission, and contributes greatly to its resilient nature. Endospores are highly resistant to disinfection, allowing them to persist on hospital surfaces. In order for the organism to cause disease, the spores must germinate and revert to a vegetative form. While spore germination in Bacillus spp. is well understood, very little is known about this process in Clostridia. Here we report the characterization of SleC (CD0551) from C. difficile 630. Bioinformatic analysis of SleC indicated a multi-domained protein possessing a peptidoglycan-binding (PGB) domain, a SpoIID/LytB domain and an undefined N-terminal region. We have confirmed that SleC is an exo-acting lytic transglycosylase with the catalytic activity localized to the N-terminal region. Additionally, we have shown that both the N-terminal catalytic domain and the C-terminal PGB domain require muramyl-δ-lactam for substrate binding. As with carbohydrate-binding modules from cellulases and xylanases, the PGB domain may be responsible for increasing the processivity of SleC by concentrating the enzyme at the surface of the substrate.
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Affiliation(s)
- Danielle Gutelius
- Department of Science and Technology, Bryant University, Smithfield, RI 02917, USA
| | - Kirsten Hokeness
- Department of Science and Technology, Bryant University, Smithfield, RI 02917, USA
| | - Susan M Logan
- National Research Council - Human Health Therapeutics Portfolio, Ottawa, ON K1A 0R6, Canada
| | - Christopher W Reid
- Department of Science and Technology, Bryant University, Smithfield, RI 02917, USA
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20
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Cox AD, St. Michael F, Aubry A, Cairns CM, Strong PCR, Hayes AC, Logan SM. Investigating the candidacy of a lipoteichoic acid-based glycoconjugate as a vaccine to combat Clostridium difficile infection. Glycoconj J 2013; 30:843-55. [DOI: 10.1007/s10719-013-9489-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/19/2013] [Accepted: 07/25/2013] [Indexed: 10/26/2022]
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21
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Janz S, Xu DX, Vachon M, Sabourin N, Cheben P, McIntosh H, Ding H, Wang S, Schmid JH, Delâge A, Lapointe J, Densmore A, Ma R, Sinclair W, Logan SM, Mackenzie R, Liu QY, Zhang D, Lopinski G, Mozenson O, Gilmour M, Tabor H. Photonic wire biosensor microarray chip and instrumentation with application to serotyping of Escherichia coli isolates. Opt Express 2013; 21:4623-4637. [PMID: 23481995 DOI: 10.1364/oe.21.004623] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A complete photonic wire molecular biosensor microarray chip architecture and supporting instrumentation is described. Chip layouts with 16 and 128 independent sensors have been fabricated and tested, where each sensor can provide an independent molecular binding curve. Each sensor is 50 μm in diameter, and consists of a millimeter long silicon photonic wire waveguide folded into a spiral ring resonator. An array of 128 sensors occupies a 2 × 2 mm2 area on a 6 × 9 mm2 chip. Microfluidic sample delivery channels are fabricated monolithically on the chip. The size and layout of the sensor array is fully compatible with commercial spotting tools designed to independently functionalize fluorescence based biochips. The sensor chips are interrogated using an instrument that delivers sample fluid to the chip and is capable of acquiring up to 128 optical sensor outputs simultaneously and in real time. Coupling light from the sensor chip is accomplished through arrays of sub-wavelength surface grating couplers, and the signals are collected by a fixed two-dimensional detector array. The chip and instrument are designed so that connection of the fluid delivery system and optical alignment are automated, and can be completed in a few seconds with no active user input. This microarray system is used to demonstrate a multiplexed assay for serotyping E. coli bacteria using serospecific polyclonal antibody probe molecules.
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Affiliation(s)
- S Janz
- National Research Council Canada (NRC), Ottawa, Ontario, K1A 0R6, Canada.
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Reid CW, Vinogradov E, Li J, Jarrell HC, Logan SM, Brisson JR. Structural characterization of surface glycans from Clostridium difficile. Carbohydr Res 2012; 354:65-73. [PMID: 22560631 DOI: 10.1016/j.carres.2012.02.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/23/2012] [Accepted: 02/09/2012] [Indexed: 12/11/2022]
Abstract
Whole-cell high-resolution magic angle spinning (HR-MAS) NMR was employed to survey the surface polysaccharides of a group of clinical and environmental isolates of Clostridium difficile. Results indicated that a highly conserved surface polysaccharide profile among all strains studied. Multiple additional peaks in the anomeric region were also observed which prompted further investigation. Structural characterization of the isolated surface polysaccharides from two strains confirmed the presence of the conserved water soluble polysaccharide originally described by Ganeshapillai et al. which was composed of a hexaglycosyl phosphate repeat consisting of [→6)-β-D-Glcp-(1-3)-β-D-GalpNAc-(1-4)-α-D-Glcp-(1-4)-[β-D-Glcp(1-3]-β-D-GalpNAc-(1-3)-α-D-Manp-(1-P→]. In addition, analysis of phenol soluble polysaccharides revealed a similarly conserved lipoteichoic acid (LTA) which could be detected on whole cells by HR-MAS NMR. Conventional NMR and mass spectrometry analysis indicated that the structure of this LTA consisted of the repeat unit [→6)-α-D-GlcpNAc-(1-3)-[→P-6]-α-D-GlcpNAc-(1-2)-D-GroA] where GroA is glyceric acid. The repeating units were linked by a phosphodiester bridge between C-6 of the two GlcNAc residues (6-P-6). A minor component consisted of GlcpN-(1-3) instead of GlcpNAc-(1-3) in the repeat unit. Through a 6-6 phosphodiester bridge this polymer was linked to →6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-6)-β-D-Glcp-(1-1)-Gro, with glycerol (Gro) substituted by fatty acids. This is the first report of the utility of HR-MAS NMR in the examination of surface carbohydrates of Gram positive bacteria and identification of a novel LTA structure from Clostridium difficile.
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Affiliation(s)
- Christopher W Reid
- National Research Council-Institute for Biological Sciences, 100 Sussex Drive, Ottawa, ON, Canada K1A 0R6
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VanDyke DJ, Wu J, Logan SM, Kelly JF, Mizuno S, Aizawa SI, Jarrell KF. Identification of genes involved in the assembly and attachment of a novel flagellin N-linked tetrasaccharide important for motility in the archaeon Methanococcus maripaludis. Mol Microbiol 2010; 72:633-44. [PMID: 19400781 DOI: 10.1111/j.1365-2958.2009.06671.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recently, the flagellin proteins of Methanococcus maripaludis were found to harbour an N-linked tetrasaccharide composed of N-acetylgalactosamine, di-acetylated glucuronic acid, an acetylated and acetamidino-modified mannuronic acid linked to threonine, and a novel terminal sugar [(5S)-2-acetamido-2,4-dideoxy-5-O-methyl-α-L-erythro-hexos-5-ulo-1,5-pyranose]. To identify genes involved in the assembly and attachment of this glycan, in-frame deletions were constructed in putative glycan assembly genes. Successful deletion of genes encoding three glycosyltransferases and an oligosaccharyltransferase (Stt3p homologue) resulted in flagellins of decreased molecular masses as evidenced by immunoblotting, indicating partial or completely absent glycan structures. Deletion of the oligosaccharyltransferase or the glycosyltransferase responsible for the transfer of the second sugar in the chain resulted in flagellins that were not assembled into flagella filaments, as evidenced by electron microscopy. Deletions of the glycosyltransferases responsible for the addition of the third and terminal sugars in the glycan were confirmed by mass spectrometry analysis of purified flagellins from these mutants. Although flagellated, these mutants had decreased motility as evidenced by semi-swarm plate analysis with the presence of each additional sugar improving movement capabilities.
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Affiliation(s)
- David J VanDyke
- Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada
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Sarkar SN, Smith LT, Logan SM, Simpkins JW. Estrogen-induced activation of extracellular signal-regulated kinase signaling triggers dendritic resident mRNA translation. Neuroscience 2010; 170:1080-5. [PMID: 20691769 PMCID: PMC3026564 DOI: 10.1016/j.neuroscience.2010.07.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 06/22/2010] [Accepted: 07/20/2010] [Indexed: 11/25/2022]
Abstract
Activated extracellular signal-regulated kinase (ERK) signaling mediated plasticity-related gene transcription has been proposed for one possible mechanism by which 17β-estradiol (E2) enhances synaptic plasticity and memory. Because activated ERK also enhances plasticity-related mRNA translation in the dendrites of neurons, we sought to determine the effects of E2 on activation of ERK, phosphorylation of translation initiation factors, and dendritic mRNA translation in hippocampal neurons. Acute E2 application resulted in a rapid, transient increase in phosphorylation of translation initiation factors, ribosomal protein (S6) and eIF4E binding protein1 (4EBP1), in an activated ERK-dependent manner. Since phosphorylation of these translation factors enhance mRNA translation, we tested E2's effect on dendritic mRNA translation. Using a green fluorescent protein (GFP)-based dendritic mRNA translation reporter (reporter plasmid construct consisted of a GFP gene fused to the 3' untranslated region (UTR) from CAMKIIα, which contains dendritic resident mRNA targeting and mRNA translational regulatory elements) we showed that E2 treatment resulted in increased somatic and dendritic GFP mRNA translation in GFP-reporter transfected hippocampal neurons. Translation inhibitor anisomycin and ERK inhibitor U0126 blocked E2 effects. Taken together, our results provide a novel mechanism by which E2 may trigger local protein synthesis of α-CaMKII in the dendrites, which is necessary for modulation of synaptic plasticity.
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Affiliation(s)
- S N Sarkar
- Department of Pharmacology and Neuroscience, University of North Texas, Health Science Center at Fort Worth, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
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Brisson JR, Vinogradov E, McNally DJ, Khieu NH, Schoenhofen IC, Logan SM, Jarrell H. The application of NMR spectroscopy to functional glycomics. Methods Mol Biol 2010; 600:155-73. [PMID: 19882127 DOI: 10.1007/978-1-60761-454-8_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Glycomics which is the study of saccharides and genes responsible for their formation requires the continuous development of rapid and sensitive methods for the identification of glycan structures. It involves glycoanalysis which relies upon the development of methods for determining the structure and interactions of carbohydrates. For the application of functional glycomics to microbial virulence, carbohydrates and their associated metabolic and carbohydrate processing enzymes and respective genes can be identified and exploited as targets for drug discovery, glyco-engineering, vaccine design, and detection and diagnosis of diseases. Glycomics also encompasses the detailed understanding of carbohydrate-protein interactions and this knowledge can be applied to research efforts focused toward the development of vaccines and immunological therapies to alleviate infectious diseases.
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Affiliation(s)
- Jean-Robert Brisson
- Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario, Canada
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26
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Rangarajan ES, Proteau A, Cui Q, Logan SM, Potetinova Z, Whitfield D, Purisima EO, Cygler M, Matte A, Sulea T, Schoenhofen IC. Structural and functional analysis of Campylobacter jejuni PseG: a udp-sugar hydrolase from the pseudaminic acid biosynthetic pathway. J Biol Chem 2009; 284:20989-1000. [PMID: 19483088 DOI: 10.1074/jbc.m109.012351] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Flagella of the bacteria Helicobacter pylori and Campylobacter jejuni are important virulence determinants, whose proper assembly and function are dependent upon glycosylation at multiple positions by sialic acid-like sugars, such as 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-nonulosonic acid (pseudaminic acid (Pse)). The fourth enzymatic step in the pseudaminic acid pathway, the hydrolysis of UDP-2,4-diacetamido-2,4,6-trideoxy-beta-l-altropyranose to generate 2,4-diacetamido-2,4,6-trideoxy-l-altropyranose, is performed by the nucleotide sugar hydrolase PseG. To better understand the molecular basis of the PseG catalytic reaction, we have determined the crystal structures of C. jejuni PseG in apo-form and as a complex with its UDP product at 1.8 and 1.85 A resolution, respectively. In addition, molecular modeling was utilized to provide insight into the structure of the PseG-substrate complex. This modeling identifies a His(17)-coordinated water molecule as the putative nucleophile and suggests the UDP-sugar substrate adopts a twist-boat conformation upon binding to PseG, enhancing the exposure of the anomeric bond cleaved and favoring inversion at C-1. Furthermore, based on these structures a series of amino acid substitution derivatives were constructed, altering residues within the active site, and each was kinetically characterized to examine its contribution to PseG catalysis. In conjunction with structural comparisons, the almost complete inactivation of the PseG H17F and H17L derivatives suggests that His(17) functions as an active site base, thereby activating the nucleophilic water molecule for attack of the anomeric C-O bond of the UDP-sugar. As the PseG structure reveals similarity to those of glycosyltransferase family-28 members, in particular that of Escherichia coli MurG, these findings may also be of relevance for the mechanistic understanding of this important enzyme family.
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Affiliation(s)
- Erumbi S Rangarajan
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1V6, Canada
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Liu F, Aubry AJ, Schoenhofen IC, Logan SM, Tanner ME. The Engineering of Bacteria Bearing Azido-Pseudaminic Acid-Modified Flagella. Chembiochem 2009; 10:1317-20. [DOI: 10.1002/cbic.200900018] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Carter AT, Paul CJ, Mason DR, Twine SM, Alston MJ, Logan SM, Austin JW, Peck MW. Independent evolution of neurotoxin and flagellar genetic loci in proteolytic Clostridium botulinum. BMC Genomics 2009; 10:115. [PMID: 19298644 PMCID: PMC2674064 DOI: 10.1186/1471-2164-10-115] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 03/19/2009] [Indexed: 11/13/2022] Open
Abstract
Background Proteolytic Clostridium botulinum is the causative agent of botulism, a severe neuroparalytic illness. Given the severity of botulism, surprisingly little is known of the population structure, biology, phylogeny or evolution of C. botulinum. The recent determination of the genome sequence of C. botulinum has allowed comparative genomic indexing using a DNA microarray. Results Whole genome microarray analysis revealed that 63% of the coding sequences (CDSs) present in reference strain ATCC 3502 were common to all 61 widely-representative strains of proteolytic C. botulinum and the closely related C. sporogenes tested. This indicates a relatively stable genome. There was, however, evidence for recombination and genetic exchange, in particular within the neurotoxin gene and cluster (including transfer of neurotoxin genes to C. sporogenes), and the flagellar glycosylation island (FGI). These two loci appear to have evolved independently from each other, and from the remainder of the genetic complement. A number of strains were atypical; for example, while 10 out of 14 strains that formed type A1 toxin gave almost identical profiles in whole genome, neurotoxin cluster and FGI analyses, the other four strains showed divergent properties. Furthermore, a new neurotoxin sub-type (A5) has been discovered in strains from heroin-associated wound botulism cases. For the first time, differences in glycosylation profiles of the flagella could be linked to differences in the gene content of the FGI. Conclusion Proteolytic C. botulinum has a stable genome backbone containing specific regions of genetic heterogeneity. These include the neurotoxin gene cluster and the FGI, each having evolved independently of each other and the remainder of the genetic complement. Analysis of these genetic components provides a high degree of discrimination of strains of proteolytic C. botulinum, and is suitable for clinical and forensic investigations of botulism outbreaks.
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Schoenhofen IC, Vinogradov E, Whitfield DM, Brisson JR, Logan SM. The CMP-legionaminic acid pathway in Campylobacter: biosynthesis involving novel GDP-linked precursors. Glycobiology 2009; 19:715-25. [PMID: 19282391 DOI: 10.1093/glycob/cwp039] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The sialic acid-like sugar 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto-nonulosonic acid, or legion-aminic acid, is found as a virulence-associated cell-surface glycoconjugate in the Gram-negative bacteria Legionella pneumophila and Campylobacter coli. L. pneumophila serogroup 1 strains, causative agents of Legionnaire's disease, contain an alpha2,4-linked homopolymer of legionaminic acid within their lipopolysaccharide O-chains, whereas the gastrointestinal pathogen C. coli modifies its flagellin with this monosaccharide via O-linkage. In this work, we have purified and biochemically characterized 11 candidate biosynthetic enzymes from Campylobacter jejuni, thereby fully reconstituting the biosynthesis of legionaminic acid and its CMP-activated form, starting from fructose-6-P. This pathway involves unique GDP-linked intermediates, likely providing a cellular mechanism for differentiating between this and similar UDP-linked pathways, such as UDP-2,4-diacetamido-bacillosamine biosynthesis involved in N-linked protein glycosylation. Importantly, these findings provide a facile method for efficient large-scale synthesis of legionaminic acid, and since legionaminic acid and sialic acid share the same D-glycero-D-galacto absolute configuration, this sugar may now be evaluated for its potential as a sialic acid mimic.
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Affiliation(s)
- Ian C Schoenhofen
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, K1A 0R6 Canada.
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Kelly J, Logan SM, Jarrell KF, VanDyke DJ, Vinogradov E. A novel N-linked flagellar glycan from Methanococcus maripaludis. Carbohydr Res 2009; 344:648-53. [PMID: 19203750 DOI: 10.1016/j.carres.2009.01.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 01/06/2009] [Accepted: 01/07/2009] [Indexed: 10/21/2022]
Abstract
The archaea Methanococcus maripaludis strain Mm900 produces flagella that are glycosylated with an N-linked tetrasaccharide. Mass spectrometric analysis of flagellar tryptic peptides identified a number of tryptic glycopeptides carrying a glycan of mass 1036.4Da, and fragmentation of the glycan oxonium ion indicated that the glycan was a tetrasaccharide. The glycan was purified, following extensive pronase digestion of flagellar filaments, by size-exclusion and anion-exchange chromatography. NMR spectroscopy revealed that the glycan had the following structure: Sug-4-beta-ManNAc3NAmA6Thr-4-beta-GlcNAc3NAcA-3-beta-GalNAc-Asn where Sug is a novel monosaccharide unit, (5S)-2-acetamido-2,4-dideoxy-5-O-methyl-alpha-l-erythro-hexos-5-ulo-1,5-pyranose. This oligosaccharide has significant similarity to the oligosaccharide that was found previously in Methanococcus voltae.
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Affiliation(s)
- John Kelly
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada K1A 0R6
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31
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Logan SM, Hui JPM, Vinogradov E, Aubry AJ, Melanson JE, Kelly JF, Nothaft H, Soo EC. Identification of novel carbohydrate modifications on Campylobacter jejuni 11168 flagellin using metabolomics-based approaches. FEBS J 2009; 276:1014-23. [PMID: 19154343 DOI: 10.1111/j.1742-4658.2008.06840.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is well known that the flagellin of Campylobacter jejuni is extensively glycosylated by pseudaminic acid and the related acetamindino derivative, in addition to flagellin glycosylation being essential for motility and colonization of host cells. Recently, the use of metabolomics permitted the unequivocal characterization of unique flagellin modifications in Campylobacter, including novel legionaminic acid sugars in Campylobacter coli, which had been impossible to ascertain in earlier studies using proteomics-based approaches. To date, the precise identities of the flagellin glycosylation modifications have only been elucidated for C. jejuni 81-176 and C. coli VC167 and those present in the first genome-sequenced strain C. jejuni 11168 remain elusive due to lability and respective levels of individual glycan modifications. We report the characterization of the carbohydrate modifications on C. jejuni 11168 flagellin using metabolomics-based approaches. Detected as their corresponding CMP-linked precursors, structural information on the flagellin modifications was obtained using a combination of MS and NMR spectroscopy. In addition to the pseudaminic acid and legionaminic acid sugars known to be present on Campylobacter flagellin, two unusual 2,3-di-O-methylglyceric acid modifications of a nonulosonate sugar were identified. By performing a metabolomic analysis of selected isogenic mutants of genes from the flagellin glycosylation locus of this pathogen, these novel CMP-linked precursors were confirmed to be di-O-methylglyceric acid derivatives of pseudaminic acid and the related acetamidino sugar. This is the first comprehensive analysis of the flagellar modifications in C. jejuni 11168 and structural elucidation of di-O-methylglyceric acid derivatives of pseudaminic acid on Campylobacter flagellin.
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Affiliation(s)
- Susan M Logan
- NRC-Institute for Biological Sciences, Ottawa, Canada
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Twine SM, Paul CJ, Vinogradov E, McNally DJ, Brisson JR, Mullen JA, McMullin DR, Jarrell HC, Austin JW, Kelly JF, Logan SM. Flagellar glycosylation in Clostridium botulinum. FEBS J 2008; 275:4428-44. [DOI: 10.1111/j.1742-4658.2008.06589.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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McNally DJ, Schoenhofen IC, Houliston RS, Khieu NH, Whitfield DM, Logan SM, Jarrell HC, Brisson JR. CMP-pseudaminic acid is a natural potent inhibitor of PseB, the first enzyme of the pseudaminic acid pathway in Campylobacter jejuni and Helicobacter pylori. ChemMedChem 2008; 3:55-9. [PMID: 17893902 DOI: 10.1002/cmdc.200700170] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- David J McNally
- National Research Council of Canada-Institute for Biological Sciences, Ottawa ON, K1A 0R6, Canada.
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Altman E, Chandan V, Larocque S, Aubry A, Logan SM, Vinogradov E, Li J. Effect of the HP0159 ORF mutation on the lipopolysaccharide structure and colonizing ability of Helicobacter pylori. ACTA ACUST UNITED AC 2008; 53:204-13. [PMID: 18430002 DOI: 10.1111/j.1574-695x.2008.00416.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The outer core region of Helicobacter pylori lipopolysaccharide of the majority of isolates contains an alpha-1,6-glucan polymer synthesized by the product of the HP0159 ORF. Structural studies carried out on HP0159 lipopolysaccharide mutants by a combination of chemical methods, mass spectrometry and nuclear magnetic resonance spectroscopy confirmed that insertional inactivation of HP0159 gene in H. pylori strains 26695 and SS1 resulted in formation of a truncated lipopolysaccharide molecule characterized by the presence of a terminal dd-heptose residue in the side-chain outer core fragment and maintaining an inner core backbone structure compared with the wild-type Lewis antigen-expressing strains. Colonization studies with HP0159 mutants of two mouse-colonizing strains, SS1 and M6, confirmed their inability to successfully colonize the murine stomach.
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Affiliation(s)
- Eleonora Altman
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, ON, Canada.
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Chandan V, Logan SM, Harrison BA, Vinogradov E, Aubry A, Stupak J, Li J, Altman E. Helicobacter pylori cagA and iceA genotypes status and risk of peptic ulcer in Saudi patients. Saudi Med J 2007; 85:582-90. [PMID: 17901900 DOI: 10.1139/o07-056] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine the prevalence of cagA+ and iceA genotypes among Helicobacter pylori (H. pylori) isolates from a group of Saudi patients with gastric complaints, and to find out any significant correlation between these strains and severe gastric clinical outcomes such as peptic ulcer and gastric cancer in Saudi population. METHODS A total of 1104 gastric biopsies from 368 patients who presented with symptoms suggestive of chronic gastritis, peptic ulcer disease, or gastric carcinoma were taken from the main hospitals in the Western region of Saudi Arabia from July 2004 to July 2005. We cultured the samples for H. pylori and a polymerase chain reaction was carried out to check for the presence or absence of cagA gene and the status of iceA genotypes. RESULTS Among the 368 suspected patients to be infected with H. pylori by means of clinical features and endoscopic findings; 103 (28%) were positive using culture technique. The relation of the presence of cagA and the development of cases to gastritis and ulcer was statistically significant (p=0.0001). Furthermore, this study revealed that 100% of ulcer cases were infected with iceA1 with a statistically significant correlation (p=0.0001), while 94.6% of gastritis and 90.9% of normal were infected with iceA2 (p=0.0001). Moreover cagA+/iceA1 combined genotypes was statistically correlated with peptic ulcer (100%) but not cagA-/iceA1 (0%; p=0.0001). CONCLUSION Certain H. pylori genotypes were more virulent than others. Multiple clinical implications based on these finding might be studied further.
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Affiliation(s)
- Vandana Chandan
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, ON, K1A 0R6, Canada
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Abstract
Campylobacter jejuni has systems for N- and O-linked protein glycosylation. Although biochemical evidence demonstrated that a pseC mutant in the O-linked pathway accumulated the product of pglF in the N-linked pathway, analyses of transformation frequencies and glycosylation statuses of N-glycosylated proteins indicated a partial suppression of pglF by pseC.
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Affiliation(s)
- Patricia Guerry
- Enteric Diseases Department, Naval Medical Research Center, 503 Robert Grant Ave., Silver Spring, MD 20910, USA.
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McNally DJ, Schoenhofen IC, Mulrooney EF, Whitfield DM, Vinogradov E, Lam JS, Logan SM, Brisson JR. Identification of labile UDP-ketosugars in Helicobacter pylori, Campylobacter jejuni and Pseudomonas aeruginosa: key metabolites used to make glycan virulence factors. Chembiochem 2007; 7:1865-8. [PMID: 17031886 DOI: 10.1002/cbic.200600298] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- David J McNally
- National Research Council of Canada-Institute for Biological Sciences, Ottawa ON, K1A 0R6, Canada.
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Schirm M, Schoenhofen IC, Logan SM, Waldron KC, Thibault P. Identification of unusual bacterial glycosylation by tandem mass spectrometry analyses of intact proteins. Anal Chem 2007; 77:7774-82. [PMID: 16316188 DOI: 10.1021/ac051316y] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The characterization of protein glycosylation can be a complex and time-consuming procedure, especially for prokaryote O-linked glycoproteins, which often comprise unusual oligosaccharide structures with no known glycosylation motif. In this report, we describe a "top-down" approach that provides information on the extent of glycosylation, the molecular masses, and the structure of oligosaccharide residues on bacterial flagella, important structural proteins involved in the motility of pathogenic bacteria. Flagella from four bacterial pathogens, namely, Campylobacter jejuni, Helicobacter pylori, Aeromonas caviae, and Listeria monocytogenes, were analyzed by this top-down mass spectrometry approach. The approach needs minimal sample preparation and can be performed within a few minutes compared to the tedious and often time-consuming "bottom-up" approach involving proteolytic digestion and LC-MS-MS analyses of the suspected glycopeptides. Multiply protonated protein precursor ions subjected to low-energy collisional activation in a quadrupole time-of-flight instrument showed extensive and specific gas-phase deglycosylation resulting in the formation of abundant oxonium ions with very few fragment ions from peptidic bond cleavages. Structural information on individual carbohydrate residues is obtained using a second-generation product ion scan of oxonium ions formed by collisional activation of the intact protein ions in the source region. The four bacterial flagella examined differed not only by the extent of glycosylation but also by the nature of carbohydrate substituents. For example, the flagellin from the Gram-positive bacterium, L. monocytogenes showed O-linked GlcNAc residues at up to 6 sites/protein monomer. In contrast, the three Gram-negative bacterial pathogens C. jejuni, H. pylori and A. caviae displayed up to 19 Ser/Thr O-linked sites modified with residues structurally related to N-acetylpseudaminic acid (Pse5Ac7Ac) and in the case of Campylobacter include a novel N-acetylglutamine substituent on Pse5Am7Ac.
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Affiliation(s)
- Michael Schirm
- Department of Chemistry, Université de Montréal, Québec, Canada
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McNally DJ, Aubry AJ, Hui JPM, Khieu NH, Whitfield D, Ewing CP, Guerry P, Brisson JR, Logan SM, Soo EC. Targeted metabolomics analysis of Campylobacter coli VC167 reveals legionaminic acid derivatives as novel flagellar glycans. J Biol Chem 2007; 282:14463-75. [PMID: 17371878 DOI: 10.1074/jbc.m611027200] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycosylation of Campylobacter flagellin is required for the biogenesis of a functional flagella filament. Recently, we used a targeted metabolomics approach using mass spectrometry and NMR to identify changes in the metabolic profile of wild type and mutants in the flagellar glycosylation locus, characterize novel metabolites, and assign function to genes to define the pseudaminic acid biosynthetic pathway in Campylobacter jejuni 81-176 (McNally, D. J., Hui, J. P., Aubry, A. J., Mui, K. K., Guerry, P., Brisson, J. R., Logan, S. M., and Soo, E. C. (2006) J. Biol. Chem. 281, 18489-18498). In this study, we use a similar approach to further define the glycome and metabolomic complement of nucleotide-activated sugars in Campylobacter coli VC167. Herein we demonstrate that, in addition to CMP-pseudaminic acid, C. coli VC167 also produces two structurally distinct nucleotide-activated nonulosonate sugars that were observed as negative ions at m/z 637 and m/z 651 (CMP-315 and CMP-329). Hydrophilic interaction liquid chromatography-mass spectrometry yielded suitable amounts of the pure sugar nucleotides for NMR spectroscopy using a cold probe. Structural analysis in conjunction with molecular modeling identified the sugar moieties as acetamidino and N-methylacetimidoyl derivatives of legionaminic acid (Leg5Am7Ac and Leg5AmNMe7Ac). Targeted metabolomic analyses of isogenic mutants established a role for the ptmA-F genes and defined two new ptm genes in this locus as legionaminic acid biosynthetic enzymes. This is the first report of legionaminic acid in Campylobacter sp. and the first report of legionaminic acid derivatives as modifications on a protein.
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Affiliation(s)
- David J McNally
- National Research Council, Institute for Biological Sciences, Ottawa, Ontario, Canada
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Paul CJ, Twine SM, Tam KJ, Mullen JA, Kelly JF, Austin JW, Logan SM. Flagellin diversity in Clostridium botulinum groups I and II: a new strategy for strain identification. Appl Environ Microbiol 2007; 73:2963-75. [PMID: 17351097 PMCID: PMC1892883 DOI: 10.1128/aem.02623-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Strains of Clostridium botulinum are traditionally identified by botulinum neurotoxin type; however, identification of an additional target for typing would improve differentiation. Isolation of flagellar filaments and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that C. botulinum produced multiple flagellin proteins. Nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) analysis of in-gel tryptic digests identified peptides in all flagellin bands that matched two homologous tandem flagellin genes identified in the C. botulinum Hall A genome. Designated flaA1 and flaA2, these open reading frames encode the major structural flagellins of C. botulinum. Colony PCR and sequencing of flaA1/A2 variable regions classified 80 environmental and clinical strains into group I or group II and clustered isolates into 12 flagellar types. Flagellar type was distinct from neurotoxin type, and epidemiologically related isolates clustered together. Sequencing a larger PCR product, obtained during amplification of flaA1/A2 from type E strain Bennett identified a second flagellin gene, flaB. LC-MS analysis confirmed that flaB encoded a large type E-specific flagellin protein, and the predicted molecular mass for FlaB matched that observed by SDS-PAGE. In contrast, the molecular mass of FlaA was 2 to 12 kDa larger than the mass predicted by the flaA1/A2 sequence of a given strain, suggesting that FlaA is posttranslationally modified. While identification of FlaB, and the observation by SDS-PAGE of different masses of the FlaA proteins, showed the flagellin proteins of C. botulinum to be diverse, the presence of the flaA1/A2 gene in all strains examined facilitates single locus sequence typing of C. botulinum using the flagellin variable region.
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Affiliation(s)
- Catherine J Paul
- Bureau of Microbial Hazards, HFPB, Health Canada, Sir Frederick G. Banting Research Centre, Ottawa, Ontario, Canada
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McNally DJ, Schoenhofen IC, Mulrooney EF, Whitfield DM, Vinogradov E, Lam JS, Logan SM, Brisson JR. Cover Picture: Identification of Labile UDP-Ketosugars in Helicobacter pylori, Campylobacter jejuni and Pseudomonas aeruginosa: Key Metabolites used to make Glycan Virulence Factors (ChemBioChem 12/2006). Chembiochem 2006. [DOI: 10.1002/cbic.200690036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chaban B, Voisin S, Kelly J, Logan SM, Jarrell KF. Identification of genes involved in the biosynthesis and attachment of Methanococcus voltae N-linked glycans: insight into N-linked glycosylation pathways in Archaea. Mol Microbiol 2006; 61:259-68. [PMID: 16824110 DOI: 10.1111/j.1365-2958.2006.05226.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N-linked glycosylation is recognized as an important post-translational modification across all three domains of life. However, the understanding of the genetic pathways for the assembly and attachment of N-linked glycans in eukaryotic and bacterial systems far outweighs the knowledge of comparable processes in Archaea. The recent characterization of a novel trisaccharide [beta-ManpNAcA6Thr-(1-4)-beta-GlcpNAc3NAcA-(1-3)-beta-GlcpNAc]N-linked to asparagine residues in Methanococcus voltae flagellin and S-layer proteins affords new opportunities to investigate N-linked glycosylation pathways in Archaea. In this contribution, the insertional inactivation of several candidate genes within the M. voltae genome and their resulting effects on flagellin and S-layer glycosylation are reported. Two of the candidate genes were shown to have effects on flagellin and S-layer protein molecular mass and N-linked glycan structure. Further examination revealed inactivation of either of these two genes also had effects on flagella assembly. These genes, designated agl (archaeal glycosylation) genes, include a glycosyl transferase (aglA) involved in the attachment of the terminal sugar to the glycan and an STT3 oligosaccharyl transferase homologue (aglB) involved in the transfer of the complete glycan to the flagellin and S-layer proteins. These findings document the first experimental evidence for genes involved in any glycosylation process within the domain Archaea.
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Affiliation(s)
- Bonnie Chaban
- Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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43
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Abstract
The biosynthesis, assembly and regulation of the flagellar apparatus has been the subject of extensive studies over many decades, with considerable attention devoted to the peritrichous flagella of Escherichia coli and Salmonella enterica. The characterization of flagellar systems from many other bacterial species has revealed subtle yet distinct differences in composition, regulation and mode of assembly of this important subcellular structure. Glycosylation of the major structural protein, the flagellin, has been shown most recently to be an important component of numerous flagellar systems in both Archaea and Bacteria, playing either an integral role in assembly or for a number of bacterial pathogens a role in virulence. This review focuses on the structural diversity in flagellar glycosylation systems and demonstrates that as a consequence of the unique assembly processes, the type of glycosidic linkage found on archaeal and bacterial flagellins is distinctive.
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Affiliation(s)
- Susan M Logan
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario K1A OR6, Canada
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Abstract
AIMS This paper reports a study to identify the types of stressors experienced by in-hospital haemodialysis patients aged 65 years and older, and the use and perceived helpfulness of coping strategies to manage these stressors. BACKGROUND Chronic renal failure and its treatments impose a variety of physical and psychosocial stressors, which challenge patients. Although the stressors and coping strategies of patients having dialysis treatment have been investigated, no study has specifically focused on older adults. Such investigation is important as the incidence of chronic kidney disease is increasing in this age group. METHOD In this descriptive, correlational study, the Haemodialysis Stressor Scale and Jalowiec Coping Scale were used to investigate stressors and coping strategies reported by 50 in-hospital haemodialysis patients aged 65 years and older. The data were collected in Canada in 2004. RESULTS Similar to previous research, the stressors of fatigue and fluid restrictions ranked highly as stressors in this sample. However, interference with social and recreational activities were stressors unique to this group. Findings challenge some common beliefs about haemodialysis patients. It is commonly believed that these patients 'get used to' haemodialysis, and therefore the number and troublesomeness of stressors decrease over time. This belief was not supported because length of time on haemodialysis did not affect participants' appraisal of stressors. Another major finding was that older participants in this sample reported the use of fewer coping strategies and found them less helpful. CONCLUSION Further research is needed to investigate factors affecting the stressors and coping responses of older haemodialysis patients and to determine their impact on health outcomes. Such knowledge will assist nurses in developing age-appropriate strategies for promoting optimum wellness for these patients who will likely spend the remainder of their life adhering to the regimen of haemodialysis.
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Affiliation(s)
- Susan M Logan
- Extra Mural Program, Atlantic Health Sciences Corporation, Saint John, New Brunswick, Canada.
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Logan SM, Chen W, Aubry A, Gidney MAJ, Lacelle S, St Michael F, Kuolee R, Higgins M, Neufeld S, Cox AD. Production of a d-glycero-d-manno-heptosyltransferase mutant of Mannheimia haemolytica displaying a veterinary pathogen specific conserved LPS structure; development and functionality of antibodies to this LPS structure. Vet Microbiol 2006; 116:175-86. [PMID: 16750602 DOI: 10.1016/j.vetmic.2006.04.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/13/2006] [Accepted: 04/18/2006] [Indexed: 11/21/2022]
Abstract
Previous structural studies of the lipopolysaccharides from the veterinary pathogens Mannheimia haemolytica (Mh), Actinobacillus pleuropneumoniae (Ap) and Pasteurella multocida (Pm) had identified a conserved inner core oligosaccharide structure that was present in all strains investigated. In order to examine the potential of this inner core structure as a vaccine, a mutagenesis strategy was adopted to interrupt a D-glycero-D-manno-heptosyltransferase gene (losB) of Mh. This gene encodes the enzyme responsible for the addition of a D-glycero-D-manno-heptose residue, the first residue beyond the conserved inner core, and its inactivation exposed the conserved inner core structure as a terminal unit on the mutant LPS molecule. Subsequent analyses confirmed the targeted structure of the mutant LPS had been obtained, and complementation with losB in trans confirmed that the losB gene encodes an alpha-1,6-D-glycero-D-manno-heptosyltransferase. Monoclonal antibodies raised in mice to this LPS structure were found to recognise LPS and whole-cells of the truncated mutant and wild-type Mh. The antibodies were bactericidal against a wild-type Mh strain and were able to passively protect mice in a model of Mh disease. This illustrates that it is possible to raise functional antibodies against the conserved inner core LPS structure.
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Affiliation(s)
- Susan M Logan
- Institute for Biological Sciences, National Research Council, Ottawa, Ont., Canada K1A 0R6
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Verma A, Schirm M, Arora SK, Thibault P, Logan SM, Ramphal R. Glycosylation of b-Type flagellin of Pseudomonas aeruginosa: structural and genetic basis. J Bacteriol 2006; 188:4395-403. [PMID: 16740946 PMCID: PMC1482937 DOI: 10.1128/jb.01642-05] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The flagellin of Pseudomonas aeruginosa can be classified into two major types-a-type or b-type-which can be distinguished on the basis of molecular weight and reactivity with type-specific antisera. Flagellin from the a-type strain PAK was shown to be glycosylated with a heterogeneous O-linked glycan attached to Thr189 and Ser260. Here we show that b-type flagellin from strain PAO1 is also posttranslationally modified with an excess mass of up to 700 Da, which cannot be explained through phosphorylation. Two serine residues at positions 191 and 195 were found to be modified. Each site had a deoxyhexose to which is linked a unique modification of 209 Da containing a phosphate moiety. In comparison to strain PAK, which has an extensive flagellar glycosylation island of 14 genes in its genome, the equivalent locus in PAO1 comprises of only four genes. PCR analysis and sequence information suggested that there are few or no polymorphisms among the islands of the b-type strains. Mutations were made in each of the genes, PA1088 to PA1091, and the flagellin from these isogenic mutants was examined by mass spectrometry to determine whether they were involved in posttranslational modification of the type-b flagellin. While mutation of PA1088, PA1089, and PA1090 genes altered the composition of the flagellin glycan, only unmodified flagellin was produced by the PA1091 mutant strain. There were no changes in motility or lipopolysaccharide banding in the mutants, implying a role that is limited to glycosylation.
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Affiliation(s)
- Amrisha Verma
- Department of Medicine/Infectious Diseases, P.O. Box 100277, JHMHC, University of Florida, Gainesville, FL 32610, USA
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Schoenhofen IC, McNally DJ, Brisson JR, Logan SM. Elucidation of the CMP-pseudaminic acid pathway in Helicobacter pylori: synthesis from UDP-N-acetylglucosamine by a single enzymatic reaction. Glycobiology 2006; 16:8C-14C. [PMID: 16751642 DOI: 10.1093/glycob/cwl010] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Flagellin glycosylation is a necessary modification allowing flagellar assembly, bacterial motility, colonization, and hence virulence for the gastrointestinal pathogen Helicobacter pylori [Josenhans, C., Vossebein, L., Friedrich, S., and Suerbaum, S. (2002) FEMS Microbiol. Lett., 210, 165-172; Schirm, M., Schoenhofen, I.C., Logan, S.M., Waldron, K.C., and Thibault, P. (2005) Anal. Chem., 77, 7774-7782]. A causative agent of gastric and duodenal ulcers, H. pylori, heavily modifies its flagellin with the sialic acid-like sugar 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-alpha-l-manno-nonulosonic acid (pseudaminic acid). Because this sugar is unique to bacteria, its biosynthetic pathway offers potential as a novel therapeutic target. We have identified six H. pylori enzymes, which reconstitute the complete biosynthesis of pseudaminic acid, and its nucleotide-activated form CMP-pseudaminic acid, from UDP-N-acetylglucosamine (UDP-GlcNAc). The pathway intermediates and final product were identified from monitoring sequential reactions with nuclear magnetic resonance (NMR) spectroscopy, thereby confirming the function of each biosynthetic enzyme. Remarkably, the conversion of UDP-GlcNAc to CMP-pseudaminic acid was achieved in a single reaction combining six enzymes. This represents the first complete in vitro enzymatic synthesis of a sialic acid-like sugar and sets the groundwork for future small molecule inhibitor screening and design. Moreover, this study provides a strategy for efficient large-scale synthesis of novel medically relevant bacterial sugars that has not been attainable by chemical methods alone.
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Affiliation(s)
- Ian C Schoenhofen
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
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McNally DJ, Hui JPM, Aubry AJ, Mui KKK, Guerry P, Brisson JR, Logan SM, Soo EC. Functional characterization of the flagellar glycosylation locus in Campylobacter jejuni 81-176 using a focused metabolomics approach. J Biol Chem 2006; 281:18489-98. [PMID: 16684771 DOI: 10.1074/jbc.m603777200] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacterial genome sequencing has provided a wealth of genetic data. However, the definitive functional characterization of hypothetical open reading frames and novel biosynthetic genes remains challenging. This is particularly true for genes involved in protein glycosylation because the isolation of their glycan moieties is often problematic. We have developed a focused metabolomics approach to define the function of flagellin glycosylation genes in Campylobacter jejuni 81-176. A capillary electrophoresis-electrospray mass spectrometry and precursor ion scanning method was used to examine cell lysates of C. jejuni 81-176 for sugar nucleotides. Novel nucleotide-activated intermediates of the pseudaminic acid (Pse5NAc7NAc) pathway and its acetamidino derivative (PseAm) were found to accumulate within select isogenic mutants, and use of a hydrophilic interaction liquid chromatography-mass spectrometry method permitted large scale purifications of the intermediates. NMR with cryo probe (cold probe) technology was utilized to complete the structural characterization of microgram quantities of CMP-5-acetamido-7-acetamidino-3,5,7,9-tetradeoxy-L-glycero-alpha-L-manno-nonulosonic acid (CMP-Pse5NAc7Am), which is the first report of Pse modified at C7 with an acetamidino group in Campylobacter, and UDP-2,4-diacetamido-2,4,6-trideoxy-alpha-D-glucopyranose, which is a bacillosamine derivative found in the N-linked proteinglycan. Using this focused metabolomics approach, pseB, pseC, pseF, pseI, and for the first time pseA, pseG, and pseH were found to be directly involved in either the biosynthesis of CMP-Pse5NAc7NAc or CMP-Pse5NAc7Am. In contrast, it was shown that pseD, pseE, Cj1314c, Cj1315c, Cjb1301, Cj1334, Cj1341c, and Cj1342c have no role in the CMP-Pse5NAc7NAc or CMP-Pse5NAc7Am pathways. These results demonstrate the usefulness of this approach for targeting compounds within the bacterial metabolome to assign function to genes, identify metabolic intermediates, and elucidate novel biosynthetic pathways.
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Affiliation(s)
- David J McNally
- National Research Council, Institute for Biological Sciences, Ottawa, Ontario K1A 0R6, Canada
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49
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Schoenhofen IC, Lunin VV, Julien JP, Li Y, Ajamian E, Matte A, Cygler M, Brisson JR, Aubry A, Logan SM, Bhatia S, Wakarchuk WW, Young NM. Structural and functional characterization of PseC, an aminotransferase involved in the biosynthesis of pseudaminic acid, an essential flagellar modification in Helicobacter pylori. J Biol Chem 2006; 281:8907-16. [PMID: 16421095 DOI: 10.1074/jbc.m512987200] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Helicobacter pylori flagellin is heavily glycosylated with the novel sialic acid-like nonulosonate, pseudaminic acid (Pse). The glycosylation process is essential for assembly of functional flagellar filaments and consequent bacterial motility. Because motility is a key virulence factor for this and other important pathogens, the Pse biosynthetic pathway offers potential for novel therapeutic targets. From recent NMR analyses, we determined that the conversion of UDP-alpha-D-Glc-NAc to the central intermediate in the pathway, UDP-4-amino-4,6-dideoxy-beta-L-AltNAc, proceeds by formation of UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-4-hexulose by the dehydratase/epimerase PseB (HP0840) followed with amino transfer by the aminotransferase, PseC (HP0366). The central role of PseC in the H. pylori Pse biosynthetic pathway prompted us to determine crystal structures of the native protein, its complexes with pyridoxal phosphate alone and in combination with the UDP-4-amino-4,6-dideoxy-beta-L-AltNAc product, the latter being converted to the external aldimine form in the active site of the enzyme. In the binding site, the AltNAc sugar ring adopts a 4C1 chair conformation, which is different from the predominant 1C4 form found in solution. The enzyme forms a homodimer where each monomer contributes to the active site, and these structures have permitted the identification of key residues involved in stabilization, and possibly catalysis, of the beta-L-arabino intermediate during the amino transfer reaction. The essential role of Lys183 in the catalytic event was confirmed by site-directed mutagenesis. This work presents for the first time a nucleotide-sugar aminotransferase co-crystallized with its natural ligand, and, in conjunction with the recent functional characterization of this enzyme, these results will assist in elucidating the aminotransferase reaction mechanism within the Pse biosynthetic pathway.
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MESH Headings
- Amino Acid Sequence
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Binding Sites
- Catalysis
- Crystallography, X-Ray
- Dimerization
- Electrophoresis, Capillary
- Electrophoresis, Polyacrylamide Gel
- Flagella/metabolism
- Glycosylation
- Helicobacter pylori/enzymology
- Helicobacter pylori/genetics
- Helicobacter pylori/growth & development
- Hydrogen Bonding
- Hydrophobic and Hydrophilic Interactions
- Kinetics
- Ligands
- Light
- Lysine/metabolism
- Models, Biological
- Models, Molecular
- Molecular Structure
- Mutagenesis, Insertional
- Mutation
- Protein Binding
- Protein Conformation
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Protein Subunits/chemistry
- Pyridoxal Phosphate/metabolism
- Scattering, Radiation
- Spectrum Analysis, Raman
- Substrate Specificity
- Transaminases/chemistry
- Transaminases/isolation & purification
- Transaminases/metabolism
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Affiliation(s)
- Ian C Schoenhofen
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario K1A 0R6
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Schoenhofen IC, McNally DJ, Vinogradov E, Whitfield D, Young NM, Dick S, Wakarchuk WW, Brisson JR, Logan SM. Functional characterization of dehydratase/aminotransferase pairs from Helicobacter and Campylobacter: enzymes distinguishing the pseudaminic acid and bacillosamine biosynthetic pathways. J Biol Chem 2005; 281:723-32. [PMID: 16286454 DOI: 10.1074/jbc.m511021200] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Helicobacter pylori and Campylobacter jejuni have been shown to modify their flagellins with pseudaminic acid (Pse), via O-linkage, while C. jejuni also possesses a general protein glycosylation pathway (Pgl) responsible for the N-linked modification of at least 30 proteins with a heptasaccharide containing 2,4-diacetamido-2,4,6-trideoxy-alpha-D-glucopyranose, a derivative of bacillosamine. To further define the Pse and bacillosamine biosynthetic pathways, we have undertaken functional characterization of UDP-alpha-D-GlcNAc modifying dehydratase/aminotransferase pairs, in particular the H. pylori and C. jejuni flagellar pairs HP0840/HP0366 and Cj1293/Cj1294, as well as the C. jejuni Pgl pair Cj1120c/Cj1121c using His(6)-tagged purified derivatives. The metabolites produced by these enzymes were identified using NMR spectroscopy at 500 and/or 600 MHz with a cryogenically cooled probe for optimal sensitivity. The metabolites of Cj1293 (PseB) and HP0840 (FlaA1) were found to be labile and could only be characterized by NMR analysis directly in aqueous reaction buffer. The Cj1293 and HP0840 enzymes exhibited C6 dehydratase as well as a newly identified C5 epimerase activity that resulted in the production of both UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-4-hexulose and UDP-2-acetamido-2,6-dideoxy-alpha-D-xylo-4-hexulose. In contrast, the Pgl dehydratase Cj1120c (PglF) was found to possess only C6 dehydratase activity generating UDP-2-acetamido-2,6-dideoxy-alpha-D-xylo-4-hexulose. Substrate-specificity studies demonstrated that the flagellar aminotransferases HP0366 and Cj1294 utilize only UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-4-hexulose as substrate producing UDP-4-amino-4,6-dideoxy-beta-L-AltNAc, a precursor in the Pse biosynthetic pathway. In contrast, the Pgl aminotransferase Cj1121c (PglE) utilizes only UDP-2-acetamido-2,6-dideoxy-alpha-D-xylo-4-hexulose producing UDP-4-amino-4,6-dideoxy-alpha-D-GlcNAc (UDP-2-acetamido-4-amino-2,4,6-trideoxy-alpha-D-glucopyranose), a precursor used in the production of the Pgl glycan component 2,4-diacetamido-2,4,6-trideoxy-alpha-D-glucopyranose.
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Affiliation(s)
- Ian C Schoenhofen
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
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