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Tomatsidou A, Krunic M, Missiakas D. Contribution of TagA-Like Glycosyltransferases to the Assembly of the Secondary Cell Wall Polysaccharide in Bacillus anthracis. J Bacteriol 2022; 204:e0025322. [PMID: 35997505 PMCID: PMC9487633 DOI: 10.1128/jb.00253-22] [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: 06/27/2022] [Accepted: 08/01/2022] [Indexed: 11/20/2022] Open
Abstract
Bacillus anthracis elaborates a secondary cell wall polysaccharide (SCWP) made of 6 to 12 trisaccharide units. Pyruvyl and acetyl substitutions of the distal unit are prerequisites for the noncovalent retention of 22 secreted Bacillus S-layer (Bsl)-associated proteins bearing an S-layer homology (SLH) domain. Surface display of Bsl proteins contributes to cell separation as well as virulence. Earlier work suggested that TagO initiates the synthesis of SCWP while GneY and GneZ, two UDP-GlcNAc 2-epimerases, synthesize ManNAc that is later incorporated in the repeat unit (→4)-ManNAc-(β1→4)-GlcNAc-(β1→6)-GlcNAc-(α1→). In organisms that synthesize wall teichoic acid, TagA catalysts have been shown to form the glycosidic bond ManNAc-(β1→4)-GlcNAc. Here, we show that genes bas2675 and bas5272, predicted to encode glycosyltransferases of the WecB/TagA/CpsF family (PFAM03808; CAZy GT26), are required for B. anthracis SCWP synthesis and S-layer assembly. Similar to tagO or gneY gneZ mutants, B. anthracis strains depleted of tagA1 (bas5272) cannot maintain cell shape, support vegetative growth, or synthesize SCWP. Expression of tagA2 (bas2675), or Staphylococcus aureus tagA on a plasmid, rescues the nonviable tagA1 mutant. We propose that TagA1 and TagA2 fulfill overlapping and key glycosyltransferase functions for the synthesis of repeat units of the SCWP of B. anthracis. IMPORTANCE Glycosyltransferases (GTs) catalyze the transfer of sugar moieties from activated donor molecules to acceptor molecules to form glycosidic bonds using a retaining or inverting mechanism. Based on the structural relatedness of their catalytic and carbohydrate-binding modules, GTs have been grouped into 115 families in the Carbohydrate-Active EnZyme (CAZy) database. For complex products, the functional assignment of GTs remains highly challenging without the knowledge of the chemical structure of the assembled polymer. Here, we propose that two uncharacterized GTs of B. anthracis belonging to the WecB/TagA/CpsF family incorporate ManNAc in repeat units of the secondary cell wall polymer of bacilli species.
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Affiliation(s)
- Anastasia Tomatsidou
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Maria Krunic
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Dominique Missiakas
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
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2
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LytR-CpsA-Psr Glycopolymer Transferases: Essential Bricks in Gram-Positive Bacterial Cell Wall Assembly. Int J Mol Sci 2021; 22:ijms22020908. [PMID: 33477538 PMCID: PMC7831098 DOI: 10.3390/ijms22020908] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/28/2022] Open
Abstract
The cell walls of Gram-positive bacteria contain a variety of glycopolymers (CWGPs), a significant proportion of which are covalently linked to the peptidoglycan (PGN) scaffolding structure. Prominent CWGPs include wall teichoic acids of Staphylococcus aureus, streptococcal capsules, mycobacterial arabinogalactan, and rhamnose-containing polysaccharides of lactic acid bacteria. CWGPs serve important roles in bacterial cellular functions, morphology, and virulence. Despite evident differences in composition, structure and underlaying biosynthesis pathways, the final ligation step of CWGPs to the PGN backbone involves a conserved class of enzymes-the LytR-CpsA-Psr (LCP) transferases. Typically, the enzymes are present in multiple copies displaying partly functional redundancy and/or preference for a distinct CWGP type. LCP enzymes require a lipid-phosphate-linked glycan precursor substrate and catalyse, with a certain degree of promiscuity, CWGP transfer to PGN of different maturation stages, according to in vitro evidence. The prototype attachment mode is that to the C6-OH of N-acetylmuramic acid residues via installation of a phosphodiester bond. In some cases, attachment proceeds to N-acetylglucosamine residues of PGN-in the case of the Streptococcus agalactiae capsule, even without involvement of a phosphate bond. A novel aspect of LCP enzymes concerns a predicted role in protein glycosylation in Actinomyces oris. Available crystal structures provide further insight into the catalytic mechanism of this biologically important class of enzymes, which are gaining attention as new targets for antibacterial drug discovery to counteract the emergence of multidrug resistant bacteria.
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Chateau A, Van der Verren SE, Remaut H, Fioravanti A. The Bacillus anthracis Cell Envelope: Composition, Physiological Role, and Clinical Relevance. Microorganisms 2020; 8:E1864. [PMID: 33255913 PMCID: PMC7759979 DOI: 10.3390/microorganisms8121864] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 12/31/2022] Open
Abstract
Anthrax is a highly resilient and deadly disease caused by the spore-forming bacterial pathogen Bacillus anthracis. The bacterium presents a complex and dynamic composition of its cell envelope, which changes in response to developmental and environmental conditions and host-dependent signals. Because of their easy to access extracellular locations, B. anthracis cell envelope components represent interesting targets for the identification and development of novel therapeutic and vaccine strategies. This review will focus on the novel insights regarding the composition, physiological role, and clinical relevance of B. anthracis cell envelope components.
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Affiliation(s)
- Alice Chateau
- Avignon Université, INRAE, UMR SQPOV, F-84914 Avignon, France;
| | - Sander E. Van der Verren
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, 1050 Brussels, Belgium; (S.E.V.d.V.); (H.R.)
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Han Remaut
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, 1050 Brussels, Belgium; (S.E.V.d.V.); (H.R.)
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
| | - Antonella Fioravanti
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, 1050 Brussels, Belgium; (S.E.V.d.V.); (H.R.)
- Structural Biology Brussels, Vrije Universiteit Brussel, 1050 Brussels, Belgium
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4
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Chateau A, Oh SY, Tomatsidou A, Brockhausen I, Schneewind O, Missiakas D. Distinct Pathways Carry Out α and β Galactosylation of Secondary Cell Wall Polysaccharide in Bacillus anthracis. J Bacteriol 2020; 202:e00191-20. [PMID: 32457049 PMCID: PMC7348550 DOI: 10.1128/jb.00191-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 05/15/2020] [Indexed: 12/26/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax disease, elaborates a secondary cell wall polysaccharide (SCWP) that is required for the retention of surface layer (S-layer) and S-layer homology (SLH) domain proteins. Genetic disruption of the SCWP biosynthetic pathway impairs growth and cell division. B. anthracis SCWP is comprised of trisaccharide repeats composed of one ManNAc and two GlcNAc residues with O-3-α-Gal and O-4-β-Gal substitutions. UDP-Gal, synthesized by GalE1, is the substrate of galactosyltransferases that modify the SCWP repeat. Here, we show that the gtsE gene, which encodes a predicted glycosyltransferase with a GT-A fold, is required for O-4-β-Gal modification of trisaccharide repeats. We identify a DXD motif critical for GtsE activity. Three distinct genes, gtsA, gtsB, and gtsC, are required for O-3-α-Gal modification of trisaccharide repeats. Based on the similarity with other three-component glycosyltransferase systems, we propose that GtsA transfers Gal from cytosolic UDP-Gal to undecaprenyl phosphate (C55-P), GtsB flips the C55-P-Gal intermediate to the trans side of the membrane, and GtsC transfers Gal onto trisaccharide repeats. The deletion of galE1 does not affect growth in vitro, suggesting that galactosyl modifications are dispensable for the function of SCWP. The deletion of gtsA, gtsB, or gtsC leads to a loss of viability, yet gtsA and gtsC can be deleted in strains lacking galE1 or gtsE We propose that the loss of viability is caused by the accumulation of undecaprenol-bound precursors and present an updated model for SCWP assembly in B. anthracis to account for the galactosylation of repeat units.IMPORTANCE Peptidoglycan is a conserved extracellular macromolecule that protects bacterial cells from turgor pressure. Peptidoglycan of Gram-positive bacteria serves as a scaffold for the attachment of polymers that provide defined bacterial interactions with their environment. One such polymer, B. anthracis SCWP, is pyruvylated at its distal end to serve as a receptor for secreted proteins bearing the S-layer homology domain. Repeat units of SCWP carry three galactoses in B. anthracis Glycosylation is a recurring theme in nature and often represents a means to mask or alter conserved molecular signatures from intruders such as bacteriophages. Several glycosyltransferase families have been described based on bioinformatics prediction, but few have been studied. Here, we describe the glycosyltransferases that mediate the galactosylation of B. anthracis SCWP.
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Affiliation(s)
- Alice Chateau
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
| | - So Young Oh
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
| | - Anastasia Tomatsidou
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Olaf Schneewind
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
| | - Dominique Missiakas
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
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5
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SpoVG is Necessary for Sporulation in Bacillus anthracis. Microorganisms 2020; 8:microorganisms8040548. [PMID: 32290166 PMCID: PMC7232415 DOI: 10.3390/microorganisms8040548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/01/2020] [Accepted: 04/08/2020] [Indexed: 01/24/2023] Open
Abstract
The Bacillus anthracis spore constitutes the infectious form of the bacterium, and sporulation is an important process in the organism’s life cycle. Herein, we show that disruption of SpoVG resulted in defective B. anthracis sporulation. Confocal microscopy demonstrated that a ΔspoVG mutant could not form an asymmetric septum, the first morphological change observed during sporulation. Moreover, levels of spoIIE mRNA were reduced in the spoVG mutant, as demonstrated using β-galactosidase activity assays. The effects on sporulation of the ΔspoVG mutation differed in B. anthracis from those in B. subtilis because of the redundant functions of SpoVG and SpoIIB in B. subtilis. SpoVG is highly conserved between B. anthracis and B. subtilis. Conversely, BA4688 (the protein tentatively assigned as SpoIIB in B. anthracis) and B. subtilis SpoIIB (SpoIIBBs) share only 27.9% sequence identity. On complementation of the B. anthracis ΔspoVG strain with spoIIBBs, the resulting strain pBspoIIBBs/ΔspoVG could not form resistant spores, but partially completed the prespore engulfment stage. In agreement with this finding, mRNA levels of the prespore engulfment gene spoIIM were significantly increased in strain pBspoIIBBs/ΔspoVG compared with the ΔspoVG strain. Transcription of the coat development gene cotE was similar in the pBspoIIBBs/ΔspoVG and ΔspoVG strains. Thus, unlike in B. subtilis, SpoVG appears to be required for sporulation in B. anthracis, which provides further insight into the sporulation mechanisms of this pathogen.
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6
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Wu X, Song Q, Han A. Interacting proteins of the essential two-component system YycFG in Bacillus subtilis. J Basic Microbiol 2019; 59:950-959. [PMID: 31339578 DOI: 10.1002/jobm.201800701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 11/06/2022]
Abstract
Two-component signal transduction systems (TCSs) play a major role in adaption and survival of microorganisms in a dynamic and sometimes dangerous environment. YycFG is an essential TCS for many Gram-positive bacteria, such as Bacillus subtilis, which regulates many important biological processes. However, its functional essentiality remains largely unknown. Here, we report several YycFG interacting proteins through coimmunoprecipitation (Co-IP) and mass spectrometry (MS) analyses. We engineered the B. subtilis genome by a knock-in approach to express YycG with a C-terminal Flag and YycF with an N-terminal HA tag. Immunoprecipitated fractions using anti-Flag or anti-HA agarose were subjected to MS analyses. A total of 41 YycG interacting proteins and four YycF interacting proteins were identified, most of which are involved in cellular metabolic processes, including cell wall synthesis and modification. The interactions of YycG with AsnB and FabL, as examples, were further validated in vitro. This study provided a clue that YycFG may be directly involved in regulation of bacterial central metabolic pathways.
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Affiliation(s)
- Xuanang Wu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Qi Song
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
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7
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Chapman RN, Liu L, Boons GJ. 4,6- O-Pyruvyl Ketal Modified N-Acetylmannosamine of the Secondary Cell Wall Polysaccharide of Bacillus anthracis Is the Anchoring Residue for Its Surface Layer Proteins. J Am Chem Soc 2018; 140:17079-17085. [PMID: 30452253 DOI: 10.1021/jacs.8b08857] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The secondary cell wall polysaccharide (SCWP) of Bacillus anthracis plays a key role in the organization of the cell envelope of vegetative cells and is intimately involved in host-guest interactions. Genetic studies have indicated that it anchors S-layer and S-layer-associated proteins, which are involved in multiple vital biological functions, to the cell surface of B. anthracis. Phenotypic observations indicate that specific functional groups of the terminal unit of SCWP, including 4,6- O-pyruvyl ketal and acetyl esters, are important for binding of these proteins. These observations are based on genetic manipulations and have not been corroborated by direct binding studies. To address this issue, a synthetic strategy was developed that could provide a range of pyruvylated oligosaccharides derived from B. anthracis SCWP bearing base-labile acetyl esters and free amino groups. The resulting oligosaccharides were used in binding studies with a panel of S-layer and S-layer-associated proteins, which identified structural features of SCWP important for binding. A single pyruvylated ManNAc monosaccharide exhibited strong binding to all proteins, making it a promising structure for S-layer protein manipulation. The acetyl esters and free amine of SCWP did not significantly impact binding, and this observation is contrary to a proposed model in which SCWP acetylation is a prerequisite for association of some but not all S-layer and S-layer-associated proteins.
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Affiliation(s)
- Robert N Chapman
- Complex Carbohydrate Research Center , University of Georgia , Athens , Georgia 30602 , United States.,Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - Lin Liu
- Complex Carbohydrate Research Center , University of Georgia , Athens , Georgia 30602 , United States
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center , University of Georgia , Athens , Georgia 30602 , United States.,Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States.,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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8
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Abstract
Bacillus anthracis, the anthrax agent, is a member of the Bacillus cereus sensu lato group, which includes invasive pathogens of mammals or insects as well as nonpathogenic environmental strains. The genes for anthrax pathogenesis are located on two large virulence plasmids. Similar virulence plasmids have been acquired by other B. cereus strains and enable the pathogenesis of anthrax-like diseases. Among the virulence factors of B. anthracis is the S-layer-associated protein BslA, which endows bacilli with invasive attributes for mammalian hosts. BslA surface display and function are dependent on the bacterial S-layer, whose constituents assemble by binding to the secondary cell wall polysaccharide (SCWP) via S-layer homology (SLH) domains. B. anthracis and other pathogenic B. cereus isolates harbor genes for the secretion of S-layer proteins, for S-layer assembly, and for synthesis of the SCWP. We review here recent insights into the assembly and function of the S-layer and the SCWP.
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Affiliation(s)
- Dominique Missiakas
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois 60649.,Department of Microbiology, University of Chicago, Chicago, Illinois 60637;
| | - Olaf Schneewind
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois 60649.,Department of Microbiology, University of Chicago, Chicago, Illinois 60637;
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9
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Chateau A, Lunderberg JM, Oh SY, Abshire T, Friedlander A, Quinn CP, Missiakas DM, Schneewind O. Galactosylation of the Secondary Cell Wall Polysaccharide of Bacillus anthracis and Its Contribution to Anthrax Pathogenesis. J Bacteriol 2018; 200:e00562-17. [PMID: 29229702 PMCID: PMC5809694 DOI: 10.1128/jb.00562-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 12/05/2017] [Indexed: 12/13/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax disease, elaborates a secondary cell wall polysaccharide (SCWP) that is essential for bacterial growth and cell division. B. anthracis SCWP is comprised of trisaccharide repeats with the structure, [→4)-β-ManNAc-(1→4)-β-GlcNAc(O3-α-Gal)-(1→6)-α-GlcNAc(O3-α-Gal, O4-β-Gal)-(1→]6-12 The genes whose products promote the galactosylation of B. anthracis SCWP are not yet known. We show here that the expression of galE1, encoding a UDP-glucose 4-epimerase necessary for the synthesis of UDP-galactose, is required for B. anthracis SCWP galactosylation. The galE1 mutant assembles surface (S) layer and S layer-associated proteins that associate with ketal-pyruvylated SCWP via their S layer homology domains similarly to wild-type B. anthracis, but the mutant displays a defect in γ-phage murein hydrolase binding to SCWP. Furthermore, deletion of galE1 diminishes the capsulation of B. anthracis with poly-d-γ-glutamic acid (PDGA) and causes a reduction in bacterial virulence. These data suggest that SCWP galactosylation is required for the physiologic assembly of the B. anthracis cell wall envelope and for the pathogenesis of anthrax disease.IMPORTANCE Unlike virulent Bacillus anthracis isolates, B. anthracis strain CDC684 synthesizes secondary cell wall polysaccharide (SCWP) trisaccharide repeats without galactosyl modification, exhibits diminished growth in vitro in broth cultures, and is severely attenuated in an animal model of anthrax. To examine whether SCWP galactosylation is a requirement for anthrax disease, we generated variants of B. anthracis strains Sterne 34F2 and Ames lacking UDP-glucose 4-epimerase by mutating the genes galE1 and galE2 We identified galE1 as necessary for SCWP galactosylation. Deletion of galE1 decreased the poly-d-γ-glutamic acid (PDGA) capsulation of the vegetative form of B. anthracis and increased the bacterial inoculum required to produce lethal disease in mice, indicating that SCWP galactosylation is indeed a determinant of anthrax disease.
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Affiliation(s)
- Alice Chateau
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Justin Mark Lunderberg
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - So Young Oh
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Teresa Abshire
- Diagnostic Systems Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Arthur Friedlander
- Headquarters, United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, USA
| | - Conrad P Quinn
- Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Dominique M Missiakas
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
| | - Olaf Schneewind
- Howard Taylor Ricketts Laboratory, Argonne National Laboratory, Lemont, Illinois, USA
- Department of Microbiology, University of Chicago, Chicago, Illinois, USA
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10
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Gale RT, Li FKK, Sun T, Strynadka NCJ, Brown ED. B. subtilis LytR-CpsA-Psr Enzymes Transfer Wall Teichoic Acids from Authentic Lipid-Linked Substrates to Mature Peptidoglycan In Vitro. Cell Chem Biol 2017; 24:1537-1546.e4. [PMID: 29107701 DOI: 10.1016/j.chembiol.2017.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Revised: 08/01/2017] [Accepted: 09/18/2017] [Indexed: 12/11/2022]
Abstract
Gram-positive bacteria endow their peptidoglycan with glycopolymers that are crucial for viability and pathogenesis. However, the cellular machinery that executes this function is not well understood. While decades of genetic and phenotypic work have highlighted the LytR-CpsA-Psr (LCP) family of enzymes as cell-wall glycopolymer transferases, their in vitro characterization has been elusive, largely due to a paucity of tools for functional assays. In this report, we synthesized authentic undecaprenyl diphosphate-linked wall teichoic acid (WTA) intermediates and built an assay system capable of monitoring LCP-mediated glycopolymer transfer. We report that all Bacillus subtilis LCP enzymes anchor WTAs to peptidoglycan in vitro. Furthermore, we probed the catalytic requirements and substrate preferences for these LCP enzymes and elaborated in vitro conditions for facile tests of enzyme function. This work sheds light on the molecular features of glycopolymer transfer and aims to aid drug discovery and development programs exploiting this promising antibacterial target.
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Affiliation(s)
- Robert T Gale
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - Franco K K Li
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Tianjun Sun
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada.
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11
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Deficiency of RgpG Causes Major Defects in Cell Division and Biofilm Formation, and Deficiency of LytR-CpsA-Psr Family Proteins Leads to Accumulation of Cell Wall Antigens in Culture Medium by Streptococcus mutans. Appl Environ Microbiol 2017; 83:AEM.00928-17. [PMID: 28687645 DOI: 10.1128/aem.00928-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/29/2017] [Indexed: 12/20/2022] Open
Abstract
Streptococcus mutans is known to possess rhamnose-glucose polysaccharide (RGP), a major cell wall antigen. S. mutans strains deficient in rgpG, encoding the first enzyme of the RGP biosynthesis pathway, were constructed by allelic exchange. The rgpG deficiency had no effect on growth rate but caused major defects in cell division and altered cell morphology. Unlike the coccoid wild type, the rgpG mutant existed primarily in chains of swollen, "squarish" dividing cells. Deficiency of rgpG also causes significant reduction in biofilm formation (P < 0.01). Double and triple mutants with deficiency in brpA and/or psr, genes coding for the LytR-CpsA-Psr family proteins BrpA and Psr, which were previously shown to play important roles in cell envelope biogenesis, were constructed using the rgpG mutant. There were no major differences in growth rates between the wild-type strain and the rgpG brpA and rgpG psr double mutants, but the growth rate of the rgpG brpA psr triple mutant was reduced drastically (P < 0.001). Under transmission electron microscopy, both double mutants resembled the rgpG mutant, while the triple mutant existed as giant cells with multiple asymmetric septa. When analyzed by immunoblotting, the rgpG mutant displayed major reductions in cell wall antigens compared to the wild type, while little or no signal was detected with the double and triple mutants and the brpA and psr single mutants. These results suggest that RgpG in S. mutans plays a critical role in cell division and biofilm formation and that BrpA and Psr may be responsible for attachment of cell wall antigens to the cell envelope.IMPORTANCEStreptococcus mutans, a major etiological agent of human dental caries, produces rhamnose-glucose polysaccharide (RGP) as the major cell wall antigen. This study provides direct evidence that deficiency of RgpG, the first enzyme of the RGP biosynthesis pathway, caused major defects in cell division and morphology and reduced biofilm formation by S. mutans, indicative of a significant role of RGP in cell division and biofilm formation in S. mutans These results are novel not only in S. mutans, but also other streptococci that produce RGP. This study also shows that the LytR-CpsA-Psr family proteins BrpA and Psr in S. mutans are involved in attachment of RGP and probably other cell wall glycopolymers to the peptidoglycan. In addition, the results also suggest that BrpA and Psr may play a direct role in cell division and biofilm formation in S. mutans This study reveals new potential targets to develop anticaries therapeutics.
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12
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Siegel SD, Liu J, Ton-That H. Biogenesis of the Gram-positive bacterial cell envelope. Curr Opin Microbiol 2016; 34:31-37. [PMID: 27497053 PMCID: PMC5164837 DOI: 10.1016/j.mib.2016.07.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 07/19/2016] [Indexed: 01/29/2023]
Abstract
The Gram-positive cell envelope serves as a molecular platform for surface display of capsular polysaccharides, wall teichoic acids (WTAs), lipoteichoic acids (LTAs), lipoproteins, surface proteins and pili. WTAs, LTAs, and sortase-assembled pili are a few features that make the Gram-positive cell envelope distinct from the Gram-negative counterpart. Interestingly, a set of LytR-CpsA-Psr family proteins, found in all Gram-positives but limited to a minority of Gram-negative organisms, plays divergent functions, while decorating the cell envelope with glycans. Furthermore, a phylum of Gram-positive bacteria, the actinobacteria, appear to employ oxidative protein folding as the major folding mechanism, typically occurring in an oxidizing environment of the Gram-negative periplasm. These distinctive features will be highlighted, along with recent findings in the cell envelope biogenesis.
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Affiliation(s)
- Sara D Siegel
- Department of Microbiology & Molecular Genetics, University of Texas McGovern Medical School, Houston, TX, USA
| | - Jun Liu
- Department of Pathology & Laboratory Medicine, University of Texas McGovern Medical School, Houston, TX, USA
| | - Hung Ton-That
- Department of Microbiology & Molecular Genetics, University of Texas McGovern Medical School, Houston, TX, USA.
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Maréchal M, Amoroso A, Morlot C, Vernet T, Coyette J, Joris B. Enterococcus hirae LcpA (Psr), a new peptidoglycan-binding protein localized at the division site. BMC Microbiol 2016; 16:239. [PMID: 27729019 PMCID: PMC5059904 DOI: 10.1186/s12866-016-0844-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 09/21/2016] [Indexed: 12/26/2022] Open
Abstract
Background Proteins from the LytR-CpsA-Psr family are found in almost all Gram-positive bacteria. Although LCP proteins have been studied in other pathogens, their functions in enterococci remain uncharacterized. The Psr protein from Enterococcus hirae, here renamed LcpA, previously associated with the regulation of the expression of the low-affinity PBP5 and β-lactam resistance, has been characterized. Results LcpA protein of E. hirae ATCC 9790 has been produced and purified with and without its transmembrane helix. LcpA appears, through different methods, to be localized in the membrane, in agreement with in silico predictions. The interaction of LcpA with E. hirae cell wall indicates that LcpA binds enterococcal peptidoglycan, regardless of the presence of secondary cell wall polymers. Immunolocalization experiments showed that LcpA and PBP5 are localized at the division site of E. hirae. Conclusions LcpA belongs to the LytR-CpsA-Psr family. Its topology, localization and binding to peptidoglycan support, together with previous observations on defective mutants, that LcpA plays a role related to the cell wall metabolism, probably acting as a phosphotransferase catalyzing the attachment of cell wall polymers to the peptidoglycan. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0844-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maxime Maréchal
- Physiologie et génétique bactérienne, Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, Liège, B-4000, Belgium
| | - Ana Amoroso
- Physiologie et génétique bactérienne, Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, Liège, B-4000, Belgium
| | - Cécile Morlot
- University Grenoble Alpes, IBS, Grenoble, F-38044, France.,CNRS, IBS, Grenoble, F-38044, France.,CEA, IBS, Grenoble, F-38044, France
| | - Thierry Vernet
- University Grenoble Alpes, IBS, Grenoble, F-38044, France.,CNRS, IBS, Grenoble, F-38044, France.,CEA, IBS, Grenoble, F-38044, France
| | - Jacques Coyette
- Physiologie et génétique bactérienne, Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, Liège, B-4000, Belgium
| | - Bernard Joris
- Physiologie et génétique bactérienne, Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, Liège, B-4000, Belgium.
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Ranjit C, Noll KM. Distension of the toga ofThermotoga maritimainvolves continued growth of the outer envelope as cells enter the stationary phase. FEMS Microbiol Lett 2016; 363:fnw218. [DOI: 10.1093/femsle/fnw218] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2016] [Indexed: 11/13/2022] Open
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Grzegorzewicz AE, de Sousa-d'Auria C, McNeil MR, Huc-Claustre E, Jones V, Petit C, Angala SK, Zemanová J, Wang Q, Belardinelli JM, Gao Q, Ishizaki Y, Mikušová K, Brennan PJ, Ronning DR, Chami M, Houssin C, Jackson M. Assembling of the Mycobacterium tuberculosis Cell Wall Core. J Biol Chem 2016; 291:18867-79. [PMID: 27417139 DOI: 10.1074/jbc.m116.739227] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
The unique cell wall of mycobacteria is essential to their viability and the target of many clinically used anti-tuberculosis drugs and inhibitors under development. Despite intensive efforts to identify the ligase(s) responsible for the covalent attachment of the two major heteropolysaccharides of the mycobacterial cell wall, arabinogalactan (AG) and peptidoglycan (PG), the enzyme or enzymes responsible have remained elusive. We here report on the identification of the two enzymes of Mycobacterium tuberculosis, CpsA1 (Rv3267) and CpsA2 (Rv3484), responsible for this function. CpsA1 and CpsA2 belong to the widespread LytR-Cps2A-Psr (LCP) family of enzymes that has been shown to catalyze a variety of glycopolymer transfer reactions in Gram-positive bacteria, including the attachment of wall teichoic acids to PG. Although individual cpsA1 and cpsA2 knock-outs of M. tuberculosis were readily obtained, the combined inactivation of both genes appears to be lethal. In the closely related microorganism Corynebacterium glutamicum, the ortholog of cpsA1 is the only gene involved in this function, and its conditional knockdown leads to dramatic changes in the cell wall composition and morphology of the bacteria due to extensive shedding of cell wall material in the culture medium as a result of defective attachment of AG to PG. This work marks an important step in our understanding of the biogenesis of the unique cell envelope of mycobacteria and opens new opportunities for drug development.
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Affiliation(s)
- Anna E Grzegorzewicz
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Célia de Sousa-d'Auria
- the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique (CEA), CNRS, Université Paris Sud, F-91198 Gif-sur-Yvette, France
| | - Michael R McNeil
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Emilie Huc-Claustre
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Victoria Jones
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Cécile Petit
- the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Shiva Kumar Angala
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Júlia Zemanová
- the Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina CH-1, 84215 Bratislava, Slovakia
| | - Qinglan Wang
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, the Key Laboratory of Medical Molecular Virology of MOE & MOH, Institutes of Biomedical Sciences and Institute of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Juan Manuel Belardinelli
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Qian Gao
- the Key Laboratory of Medical Molecular Virology of MOE & MOH, Institutes of Biomedical Sciences and Institute of Medical Microbiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Yoshimasa Ishizaki
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, the Institute of Microbial Chemistry (BIKAKEN), Kamiosaki, Shinagawa-ku, Tokyo 3-14-23, Japan, and
| | - Katarína Mikušová
- the Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina CH-1, 84215 Bratislava, Slovakia
| | - Patrick J Brennan
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682
| | - Donald R Ronning
- the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390
| | - Mohamed Chami
- the C-CINA Center for Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Christine Houssin
- the Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique (CEA), CNRS, Université Paris Sud, F-91198 Gif-sur-Yvette, France,
| | - Mary Jackson
- From the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682,
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