1
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Unay J, Kint N, Viollier PH. Evolution of paralogous multicomponent systems for site-specific O-sialylation of flagellin in Gram-negative and Gram-positive bacteria. Curr Biol 2024; 34:2932-2947.e7. [PMID: 38897200 DOI: 10.1016/j.cub.2024.05.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 05/13/2024] [Accepted: 05/24/2024] [Indexed: 06/21/2024]
Abstract
Many bacteria glycosylate flagellin on serine or threonine residues using pseudaminic acid (Pse) or other sialic acid-like donor sugars. Successful reconstitution of Pse-dependent sialylation by the conserved Maf-type flagellin glycosyltransferase (fGT) may require (a) missing component(s). Here, we characterize both Maf paralogs in the Gram-negative bacterium Shewanella oneidensis MR-1 and reconstitute Pse-dependent glycosylation in heterologous hosts. Remarkably, we uncovered distinct acceptor determinants and target specificities for each Maf. Whereas Maf-1 uses its C-terminal tetratricopeptide repeat (TPR) domain to confer flagellin acceptor and O-glycosylation specificity, Maf-2 requires the newly identified conserved specificity factor, glycosylation factor for Maf (GlfM), to form a ternary complex with flagellin. GlfM orthologs are co-encoded with Maf-2 in Gram-negative and Gram-positive bacteria and require an invariant aspartate in their four-helix bundle to function with Maf-2. Thus, convergent fGT evolution underlies distinct flagellin-binding modes in tripartite versus bipartite systems and, consequently, distinct O-glycosylation preferences of acceptor serine residues with Pse.
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Affiliation(s)
- Jovelyn Unay
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Nicolas Kint
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, 75006 Paris, France
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland.
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2
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Walklett AJ, Flack EKP, Chidwick HS, Hatton NE, Keenan T, Budhadev D, Walton J, Thomas GH, Fascione MA. The Retaining Pse5Ac7Ac Pseudaminyltransferase KpsS1 Defines a Previously Unreported glycosyltransferase family (GT118). Angew Chem Int Ed Engl 2024; 63:e202318523. [PMID: 38224120 DOI: 10.1002/anie.202318523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 01/16/2024]
Abstract
Cell surface sugar 5,7-diacetyl pseudaminic acid (Pse5Ac7Ac) is a bacterial analogue of the ubiquitous sialic acid, Neu5Ac, and contributes to the virulence of a number of multidrug resistant bacteria, including ESKAPE pathogens Pseudomonas aeruginosa, and Acinetobacter baumannii. Despite its discovery in the surface glycans of bacteria over thirty years ago, to date no glycosyltransferase enzymes (GTs) dedicated to the synthesis of a pseudaminic acid glycosidic linkage have been unequivocally characterised in vitro. Herein we demonstrate that A. baumannii KpsS1 is a dedicated pseudaminyltransferase enzyme (PseT) which constructs a Pse5Ac7Ac-α(2,6)-Glcp linkage, and proceeds with retention of anomeric configuration. We utilise this PseT activity in tandem with the biosynthetic enzymes required for CMP-Pse5Ac7Ac assembly, in a two-pot, seven enzyme synthesis of an α-linked Pse5Ac7Ac glycoside. Due to its unique activity and protein sequence, we also assign KpsS1 as the prototypical member of a previously unreported GT family (GT118).
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Affiliation(s)
| | - Emily K P Flack
- Department of Chemistry, University of York, York, YO10 5DD, UK
- Department of Biology, University of York, York, YO10 5DD, UK
| | | | | | - Tessa Keenan
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | | | - Julia Walton
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Gavin H Thomas
- Department of Biology, University of York, York, YO10 5DD, UK
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3
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Kint N, Dubois T, Viollier PH. Stereoisomer-specific reprogramming of a bacterial flagellin sialyltransferase. EMBO J 2023; 42:e112880. [PMID: 36636824 PMCID: PMC9975948 DOI: 10.15252/embj.2022112880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/02/2022] [Accepted: 12/16/2022] [Indexed: 01/14/2023] Open
Abstract
Glycosylation of surface structures diversifies cells chemically and physically. Nucleotide-activated sialic acids commonly serve as glycosyl donors, particularly pseudaminic acid (Pse) and its stereoisomer legionaminic acid (Leg), which decorate eubacterial and archaeal surface layers or protein appendages. FlmG, a recently identified protein sialyltransferase, O-glycosylates flagellins, the subunits of the flagellar filament. We show that flagellin glycosylation and motility in Caulobacter crescentus and Brevundimonas subvibrioides is conferred by functionally insulated Pse and Leg biosynthesis pathways, respectively, and by specialized FlmG orthologs. We established a genetic glyco-profiling platform for the classification of Pse or Leg biosynthesis pathways, discovered a signature determinant of eubacterial and archaeal Leg biosynthesis, and validated it by reconstitution experiments in a heterologous host. Finally, by rewiring FlmG glycosylation using chimeras, we defined two modular determinants that govern flagellin glycosyltransferase specificity: a glycosyltransferase domain that either donates Leg or Pse and a specialized flagellin-binding domain that identifies the acceptor.
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Affiliation(s)
- Nicolas Kint
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of MedicineUniversity of GenevaGenèveSwitzerland
| | - Thomas Dubois
- University of Lille, CNRS, INRAE, Centrale Lille, UMR 8207‐UMET‐Unité Matériaux et TransformationsLilleFrance
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of MedicineUniversity of GenevaGenèveSwitzerland
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4
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Lowry RC, Allihaybi L, Parker JL, Couto NAS, Stafford GP, Shaw JG. Heterogeneous glycosylation and methylation of the
Aeromonas caviae
flagellin. Microbiologyopen 2022; 11:e1306. [PMID: 36031959 PMCID: PMC9290775 DOI: 10.1002/mbo3.1306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/05/2022] [Accepted: 07/05/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Rebecca C. Lowry
- Department of Infection Immunity and Cardiovascular Disease University of Sheffield Medical School Sheffield UK
| | - Laila Allihaybi
- Department of Infection Immunity and Cardiovascular Disease University of Sheffield Medical School Sheffield UK
| | - Jennifer L. Parker
- Department of Infection Immunity and Cardiovascular Disease University of Sheffield Medical School Sheffield UK
| | | | - Graham P. Stafford
- School of Clinical Dentistry, Claremont Crescent University of Sheffield Sheffield UK
| | - Jonathan G. Shaw
- Department of Infection Immunity and Cardiovascular Disease University of Sheffield Medical School Sheffield UK
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5
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Meng X, Boons GJ, Wösten MMSM, Wennekes T. Metabolic Labeling of Legionaminic Acid in Flagellin Glycosylation of Campylobacter jejuni Identifies Maf4 as a Putative Legionaminyl Transferase. Angew Chem Int Ed Engl 2021; 60:24811-24816. [PMID: 34519150 PMCID: PMC9298399 DOI: 10.1002/anie.202107181] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Indexed: 12/19/2022]
Abstract
Campylobacter jejuni is the major human food‐borne pathogen. Its bipolar flagella are heavily O‐glycosylated with microbial sialic acids and essential for its motility and pathogenicity. However, both the glycosylation of flagella and the exact contribution of legionaminic acid (Leg) to flagellar activity is poorly understood. Herein, we report the development of a metabolic labeling method for Leg glycosylation on bacterial flagella with probes based on azide‐modified Leg precursors. The hereby azido‐Leg labeled flagellin could be detected by Western blot analysis and imaged on intact bacteria. Using the probes on C. jejuni and its isogenic maf4 mutant we also further substantiated the identification of Maf4 as a putative Leg glycosyltransferase. Further evidence was provided by UPLC–MS detection of labeled CMP‐Leg and an in silico model of Maf4. This method and the developed probes will facilitate the study of Leg glycosylation and the functional role of this modification in C. jejuni motility and invasiveness.
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Affiliation(s)
- Xianke Meng
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
| | - Geert-Jan Boons
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands.,Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, USA
| | - Marc M S M Wösten
- Department Biomolecular Health Sciences, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands
| | - Tom Wennekes
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands
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6
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Meng X, Boons G, Wösten MMSM, Wennekes T. Metabolic Labeling of Legionaminic Acid in Flagellin Glycosylation of
Campylobacter jejuni
Identifies Maf4 as a Putative Legionaminyl Transferase. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xianke Meng
- Department of Chemical Biology and Drug Discovery Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research Utrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Geert‐Jan Boons
- Department of Chemical Biology and Drug Discovery Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research Utrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands
- Complex Carbohydrate Research Center and Department of Chemistry University of Georgia 315 Riverbend Road Athens GA 30602 USA
| | - Marc M. S. M. Wösten
- Department Biomolecular Health Sciences Utrecht University Yalelaan 1 3584 CL Utrecht The Netherlands
| | - Tom Wennekes
- Department of Chemical Biology and Drug Discovery Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research Utrecht University Universiteitsweg 99 3584 CG Utrecht The Netherlands
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7
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Kint N, Unay J, Viollier PH. Specificity and modularity of flagellin nonulosonic acid glycosyltransferases. Trends Microbiol 2021; 30:109-111. [PMID: 34782242 DOI: 10.1016/j.tim.2021.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 12/28/2022]
Abstract
Many bacterial flagella are specifically O-glycosylated with nonulosonic acids, including the sialic acid derivatives, pseudaminic acid or legionaminic acid. Unlike protein glycosyltransferases that are extracytoplasmic, flagellin glycosyltransferases (fGTs) act cytoplasmically with unknown donor or acceptor specificities. The recent reconstitution of fGT-based glycosylation in heterologous hosts enables analyses underpinning such specificity.
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Affiliation(s)
- Nicolas Kint
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Jovelyn Unay
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Patrick H Viollier
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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8
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Yang K, Kao C, Su MS, Wang S, Chen Y, Hu S, Chen J, Teng C, Tsai P, Wu J. Glycosyltransferase Jhp0106 (PseE) contributes to flagellin maturation in Helicobacter pylori. Helicobacter 2021; 26:e12787. [PMID: 33586844 PMCID: PMC7988653 DOI: 10.1111/hel.12787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 01/25/2023]
Abstract
BACKGROUND Flagella-mediated motility is both a crucial virulence determinant of Helicobacter pylori and a factor associated with gastrointestinal diseases. Flagellar formation requires flagellins to be glycosylated with pseudaminic acid (Pse), a process that has been extensively studied. However, the transfer of Pse to flagellins remains poorly understood. Therefore, the aim of this study is to characterize a putative glycosyltransferase jhp0106 in flagellar formation. MATERIALS AND METHODS Western blotting and chemical deglycosylation were performed to examine FlaA glycosylation. Protein structural analyses were executed to identify the active site residues of Jhp0106, while the Jhp0106-FlaA interaction was examined using a bacterial two-hybrid assay. Lastly, site-directed mutants with mutated active site residues in the jhp0106 gene were generated and investigated using a motility assay, Western blotting, cDNA-qPCR analysis, and electron microscopic examination. RESULTS Loss of flagellar formation in the Δjhp0106 mutant was confirmed to be associated with non-glycosylated FlaA. Furthermore, three active site residues of Jhp0106 (S350, F376, and E415) were identified within a potential substrate-binding region. The interaction between FlaA and Jhp0106, Jhp0106::S350A, Jhp0106::F376A, or Jhp0106::E415A was determined to be significant. As well, the substitution of S350A, F376A, or E415A in the site-directed Δjhp0106 mutants resulted in impaired motility, deficient FlaA glycosylation, and lacking flagella. However, these phenotypic changes were regardless of flaA expression, implying an indefinite proteolytic degradation of FlaA occurred. CONCLUSIONS This study demonstrated that Jhp0106 (PseE) binds to FlaA mediating FlaA glycosylation and flagellar formation. Our discovery of PseE has revealed a new glycosyltransferase family responsible for flagellin glycosylation in pathogens.
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Affiliation(s)
- Kai‐Yuan Yang
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan
| | - Cheng‐Yen Kao
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan,Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Marcia Shu‐Wei Su
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Shuying Wang
- Department of Microbiology and ImmunologyCollege of MedicineNational Cheng‐Kung UniversityTainanTaiwan
| | - Yueh‐Lin Chen
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Shiau‐Ting Hu
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan
| | - Jenn‐Wei Chen
- Department of Microbiology and ImmunologyCollege of MedicineNational Cheng‐Kung UniversityTainanTaiwan
| | - Ching‐Hao Teng
- Institute of Molecular MedicineCollege of MedicineNational Cheng Kung UniversityTainanTaiwan
| | - Pei‐Jane Tsai
- Department of Medical Laboratory Science and BiotechnologyCollege of MedicineNational Cheng Kung UniversityTainanTaiwan
| | - Jiunn‐Jong Wu
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
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9
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Ardissone S, Kint N, Viollier PH. Specificity in glycosylation of multiple flagellins by the modular and cell cycle regulated glycosyltransferase FlmG. eLife 2020; 9:e60488. [PMID: 33108275 PMCID: PMC7591256 DOI: 10.7554/elife.60488] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
How specificity is programmed into post-translational modification of proteins by glycosylation is poorly understood, especially for O-linked glycosylation systems. Here we reconstitute and dissect the substrate specificity underpinning the cytoplasmic O-glycosylation pathway that modifies all six flagellins, five structural and one regulatory paralog, in Caulobacter crescentus, a monopolarly flagellated alpha-proteobacterium. We characterize the biosynthetic pathway for the sialic acid-like sugar pseudaminic acid and show its requirement for flagellation, flagellin modification and efficient export. The cognate NeuB enzyme that condenses phosphoenolpyruvate with a hexose into pseudaminic acid is functionally interchangeable with other pseudaminic acid synthases. The previously unknown and cell cycle-regulated FlmG protein, a defining member of a new class of cytoplasmic O-glycosyltransferases, is required and sufficient for flagellin modification. The substrate specificity of FlmG is conferred by its N-terminal flagellin-binding domain. FlmG accumulates before the FlaF secretion chaperone, potentially timing flagellin modification, export, and assembly during the cell division cycle.
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Affiliation(s)
- Silvia Ardissone
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Nicolas Kint
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
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10
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Khairnar A, Sunsunwal S, Babu P, Ramya TNC. Novel serine/threonine-O-glycosylation with N-acetylneuraminic acid and 3-deoxy-D-manno-octulosonic acid by bacterial flagellin glycosyltransferases. Glycobiology 2020; 31:288-306. [PMID: 32886756 DOI: 10.1093/glycob/cwaa084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/05/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022] Open
Abstract
Some bacterial flagellins are O-glycosylated on surface-exposed serine/threonine residues with nonulosonic acids such as pseudaminic acid, legionaminic acid and their derivatives by flagellin nonulosonic acid glycosyltransferases, also called motility-associated factors (Maf). We report here two new glycosidic linkages previously unknown in any organism, serine/threonine-O-linked N-acetylneuraminic acid (Ser/Thr-O-Neu5Ac) and serine/threonine-O-linked 3-deoxy-D-manno-octulosonic acid or keto-deoxyoctulosonate (Ser/Thr-O-KDO), both catalyzed by Geobacillus kaustophilus Maf and Clostridium botulinum Maf. We identified these novel glycosidic linkages in recombinant G. kaustophilus and C. botulinum flagellins that were coexpressed with their cognate recombinant Maf protein in Escherichia coli strains producing the appropriate nucleotide sugar glycosyl donor. Our finding that both G. kaustophilus Maf (putative flagellin sialyltransferase) and C. botulinum Maf (putative flagellin legionaminic acid transferase) catalyzed Neu5Ac and KDO transfer on to flagellin indicates that Maf glycosyltransferases display donor substrate promiscuity. Maf glycosyltransferases have the potential to radically expand the scope of neoglycopeptide synthesis and posttranslational protein engineering.
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Affiliation(s)
- Aasawari Khairnar
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Sonali Sunsunwal
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Ponnusamy Babu
- Glycomics and Glycoproteomics & Biologics Characterization Facility, Centre for Cellular and Molecular Platforms, National Centre for Biological Sciences-TIFR, Bengaluru, UAS-GKVK Campus, Bellary Road, 560065, India
| | - T N C Ramya
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
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11
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The sps Genes Encode an Original Legionaminic Acid Pathway Required for Crust Assembly in Bacillus subtilis. mBio 2020; 11:mBio.01153-20. [PMID: 32817102 PMCID: PMC7439481 DOI: 10.1128/mbio.01153-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The crust is the outermost spore layer of most Bacillus strains devoid of an exosporium. This outermost layer, composed of both proteins and carbohydrates, plays a major role in the adhesion and spreading of spores into the environment. Recent studies have identified several crust proteins and have provided insights about their organization at the spore surface. However, although carbohydrates are known to participate in adhesion, little is known about their composition, structure, and localization. In this study, we showed that the spore surface of Bacillus subtilis is covered with legionaminic acid (Leg), a nine-carbon backbone nonulosonic acid known to decorate the flagellin of the human pathogens Helicobacter pylori and Campylobacter jejuni We demonstrated that the spsC, spsD, spsE, spsG, and spsM genes of Bacillus subtilis are required for Leg biosynthesis during sporulation, while the spsF gene is required for Leg transfer from the mother cell to the surface of the forespore. We also characterized the activity of SpsM and highlighted an original Leg biosynthesis pathway in B. subtilis Finally, we demonstrated that Leg is required for the assembly of the crust around the spores, and we showed that in the absence of Leg, spores were more adherent to stainless steel probably because of their reduced hydrophilicity and charge.IMPORTANCE Bacillus species are a major economic and food safety concern of the food industry because of their food spoilage-causing capability and persistence. Their persistence is mainly due to their ability to form highly resistant spores adhering to the surfaces of industrial equipment. Spores of the Bacillus subtilis group are surrounded by the crust, a superficial layer which plays a key role in their adhesion properties. However, knowledge of the composition and structure of this layer remains incomplete. Here, for the first time, we identified a nonulosonic acid (Leg) at the surfaces of bacterial spores (B. subtilis). We uncovered a novel Leg biosynthesis pathway, and we demonstrated that Leg is required for proper crust assembly. This work contributes to the description of the structure and composition of Bacillus spores which has been under way for decades, and it provides keys to understanding the importance of carbohydrates in Bacillus adhesion and persistence in the food industry.
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12
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Azurmendi HF, Veeramachineni V, Freese S, Lichaa F, Freedberg DI, Vann WF. Chemical structure and genetic organization of the E. coli O6:K15 capsular polysaccharide. Sci Rep 2020; 10:12608. [PMID: 32724125 PMCID: PMC7387560 DOI: 10.1038/s41598-020-69476-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022] Open
Abstract
Capsular polysaccharides are important virulence factors in pathogenic bacteria. Characterizing the structural components and biosynthetic pathways for these polysaccharides is key to our ability to design vaccines and other preventative therapies that target encapsulated pathogens. Many gram-negative pathogens such as Neisseria meningitidis and Escherichia coli express acidic capsules. The E. coli K15 serotype has been identified as both an enterotoxigenic and uropathogenic pathogen. Despite its relevance as a disease-causing serotype, the associated capsular polysaccharide remains poorly characterized. We describe in this report the chemical structure of the K15 polysaccharide, based on chemical analysis and nuclear magnetic resonance (NMR) data. The repeating structure of the K15 polysaccharide consists of 4)-α-GlcpNAc-(1 → 5)-α-KDOp-(2 → partially O-acetylated at 3-hydroxyl of GlcNAc. We also report, the organization of the gene cluster responsible for capsule biosynthesis. We identify genes in this cluster that potentially encode an O-acetyltransferase, an N-acetylglucosamine transferase, and a KDO transferase consistent with the structure we report.
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Affiliation(s)
- Hugo F Azurmendi
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Vamsee Veeramachineni
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Stephen Freese
- Affinivax, 650 East Kendall St, Cambridge, MA, 02138, USA
| | - Flora Lichaa
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Darón I Freedberg
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Willie F Vann
- Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA.
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13
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Type III Secretion Effectors with Arginine N-Glycosyltransferase Activity. Microorganisms 2020; 8:microorganisms8030357. [PMID: 32131463 PMCID: PMC7142665 DOI: 10.3390/microorganisms8030357] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 01/31/2023] Open
Abstract
Type III secretion systems are used by many Gram-negative bacterial pathogens to inject proteins, known as effectors, into the cytosol of host cells. These virulence factors interfere with a diverse array of host signal transduction pathways and cellular processes. Many effectors have catalytic activities to promote post-translational modifications of host proteins. This review focuses on a family of effectors with glycosyltransferase activity that catalyze addition of N-acetyl-d-glucosamine to specific arginine residues in target proteins, leading to reduced NF-κB pathway activation and impaired host cell death. This family includes NleB from Citrobacter rodentium, NleB1 and NleB2 from enteropathogenic and enterohemorrhagic Escherichia coli, and SseK1, SseK2, and SseK3 from Salmonella enterica. First, we place these effectors in the general framework of the glycosyltransferase superfamily and in the particular context of the role of glycosylation in bacterial pathogenesis. Then, we provide detailed information about currently known members of this family, their role in virulence, and their targets.
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14
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Flack EKP, Chidwick HS, Best M, Thomas GH, Fascione MA. Synthetic Approaches for Accessing Pseudaminic Acid (Pse) Bacterial Glycans. Chembiochem 2020; 21:1397-1407. [PMID: 31944494 DOI: 10.1002/cbic.202000019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Indexed: 12/18/2022]
Abstract
Pseudaminic acids (Pses) are a group of non-mammalian nonulosonic acids (nulOs) that have been shown to be an important virulence factor for a number of pathogenic bacteria, including emerging multidrug-resistant ESKAPE pathogens. Despite their discovery over 30 years ago, relatively little is known about the biological significance of Pse glycans compared with their sialic acid analogues, primarily due to a lack of access to the synthetically challenging Pse architecture. Recently, however, the Pse backbone has been subjected to increasing synthetic exploration by carbohydrate (bio)chemists, and the total synthesis of complex Pse glycans achieved with inspiration from the biosynthesis and subsequent detailed study of chemical glycosylation by using Pse donors. Herein, context is provided for these efforts by summarising recent synthetic approaches pioneered for accessing Pse glycans, which are set to open up this underexplored area of glycoscience to the wider scientific community.
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Affiliation(s)
- Emily K P Flack
- Department of Chemistry, University of York, Heslington Road, Heslington, York, YO10 5DD, UK
| | - Harriet S Chidwick
- Department of Chemistry, University of York, Heslington Road, Heslington, York, YO10 5DD, UK
| | - Matthew Best
- Department of Chemistry, University of York, Heslington Road, Heslington, York, YO10 5DD, UK
| | - Gavin H Thomas
- Department of Biology, University of York, Heslington Road, Heslington, York, YO10 5DD, UK
| | - Martin A Fascione
- Department of Chemistry, University of York, Heslington Road, Heslington, York, YO10 5DD, UK
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15
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Koomey M. O-linked protein glycosylation in bacteria: snapshots and current perspectives. Curr Opin Struct Biol 2019; 56:198-203. [DOI: 10.1016/j.sbi.2019.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/22/2019] [Accepted: 03/13/2019] [Indexed: 12/27/2022]
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16
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Shi X, Hu HW, Zhu-Barker X, Hayden H, Wang J, Suter H, Chen D, He JZ. Nitrifier-induced denitrification is an important source of soil nitrous oxide and can be inhibited by a nitrification inhibitor 3,4-dimethylpyrazole phosphate. Environ Microbiol 2017; 19:4851-4865. [DOI: 10.1111/1462-2920.13872] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/24/2017] [Indexed: 02/03/2023]
Affiliation(s)
- Xiuzhen Shi
- Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Parkville Victoria 3010 Australia
| | - Hang-Wei Hu
- Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Parkville Victoria 3010 Australia
| | - Xia Zhu-Barker
- Biogeochemistry and Nutrient Cycling Laboratory, Department of Land, Air and Water Resources; University of California; Davis CA 95616 USA
| | - Helen Hayden
- Department of Economic Development; Jobs, Transport and Resources, AgriBio, 5 Ring Rd; Bundoora Victoria 3083 Australia
| | - Juntao Wang
- State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-environmental Sciences; Chinese Academy of Sciences; Beijing 100085 China
| | - Helen Suter
- Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Parkville Victoria 3010 Australia
| | - Deli Chen
- Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Parkville Victoria 3010 Australia
| | - Ji-Zheng He
- Faculty of Veterinary and Agricultural Sciences; The University of Melbourne; Parkville Victoria 3010 Australia
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