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Wang X, Xu Y, Martin NI, Breukink E. The enigmatic mode of action of the lantibiotic epilancin 15X. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184282. [PMID: 38218577 DOI: 10.1016/j.bbamem.2024.184282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/21/2023] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Epilancin 15X is a lantibiotic that has an antimicrobial activity in the nanomolar concentration range towards Staphylococcus simulans. Such low MICs usually imply that these peptides employ a mechanism of action (MoA) involving high affinity targets. Here we studied this MoA by using epilancin 15X's ability to dissipate the membrane potential of intact S. simulans cells. These membrane depolarization assays showed that treatment of the bacteria by antibiotics known to affect the bacterial cell wall synthesis pathway decreased the membrane depolarization effects of epilancin 15X. Disruption of the Lipid II cycle in intact bacteria using several methods led to a decrease in the activity of epilancin 15X. Antagonism-based experiments on 96-well plate and agar diffusion plate pointed towards a possible interaction between epilancin 15X and Lipid II and this was confirmed by Circular Dichroism (CD) based experiments. However, this interaction did not lead to a detectable effect on either carboxyfluorescein (CF) leakage or proton permeability. All experiments point to the involvement of a phosphodiester-containing target within a polyisoprene-based biosynthesis pathway, yet the exact identity of the target remains obscure so far.
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Affiliation(s)
- Xiaoqi Wang
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Yang Xu
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, Netherlands
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, Netherlands
| | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, Netherlands; Zhejiang Provincial Key Laboratory of Food Microbiotechnology Research of China, the Zhejiang Gongshang University of China, Hangzhou, China.
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2
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Han J, Zhao X, Zhao X, Li P, Gu Q. Insight into the structure, biosynthesis, isolation method and biological function of teichoic acid in different gram-positive microorganisms: A review. Int J Biol Macromol 2023; 253:126825. [PMID: 37696369 DOI: 10.1016/j.ijbiomac.2023.126825] [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: 07/11/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/13/2023]
Abstract
Teichoic acid (TA) is a weakly anionic polymer present in the cell walls of Gram-positive bacteria. It can be classified into wall teichoic acid (WTA) and lipoteichoic acid (LTA) based on its localization in the cell wall. The structure and biosynthetic pathway of TAs are strain-specific and have a significant role in maintaining cell wall stability. TAs have various beneficial functions, such as immunomodulatory, anticancer and antioxidant activities. However, the purity and yield of TAs are generally not high, and different isolation methods may even affect their structural integrity, which limits the research progress on the probiotic functions of TA. This paper reviews an overview of the structure and biosynthetic pathway of TAs in different strains, as well as the research progress of the isolation and purification methods of TAs. Furthermore, this review also highlights the current research status on the biological functions of TAs. Through a comprehensive understanding of this review, it is expected to pave the way for advancements in isolating and purifying high-quality TAs and, in turn, lay a foundation for contributing to the development of targeted probiotic therapies.
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Affiliation(s)
- Jiarun Han
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Xin Zhao
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Xilian Zhao
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Ping Li
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China
| | - Qing Gu
- Key Laboratory for Food Microbial Technology of Zhejiang Province, College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, People's Republic of China.
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Goetsch AG, Ufearo D, Keiser G, Heiss C, Azadi P, Hershey DM. A novel exopolysaccharide pathway from a freshwater Sphingomonas isolate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.03.565537. [PMID: 37961232 PMCID: PMC10635127 DOI: 10.1101/2023.11.03.565537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Bacteria embellish their cell envelopes with a variety of specialized polysaccharides. Biosynthesis pathways for these glycans are complex, and final products vary greatly in their chemical structures, physical properties and biological activities. This tremendous diversity comes from the ability to arrange complex pools of monosaccharide building blocks into polymers with many possible linkage configurations. Due to the complex chemistry of bacterial glycans, very few biosynthetic pathways have been defined in detail. To better understand the breadth of polysaccharide production in nature we isolated a bacterium from Lake Michigan called Sphingomonas sp. LM7 that is proficient in exopolysaccharide (EPS) production. We identified genes that contribute to EPS biosynthesis in LM7 by screening a transposon mutant library for colonies displaying altered colony morphology. A gene cluster was identified that appears to encode a complete wzy/wzx-dependent polysaccharide assembly pathway. Deleting individual genes in this cluster caused a non-mucoid phenotype and a corresponding loss of EPS secretion, confirming that LM7 assembles a novel wzy/wzx-dependent polysaccharide. We extracted EPS from LM7 cultures and showed that it contains a linear chain of 3- and 4- linked glucose, galactose, and glucuronic acid residues. Finally, we found that the EPS pathway we identified diverges from those of adhesive polysaccharides such as the holdfast that are conserved in higher Alphaproteobacteria. Our approach of characterizing complete biosynthetic pathways holds promise for engineering of polysaccharides with valuable properties.
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Affiliation(s)
- Alexandra G. Goetsch
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Daniel Ufearo
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Griffin Keiser
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Christian Heiss
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - David M. Hershey
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
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4
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Patel H, Rawat S. A genetic regulatory see-saw of biofilm and virulence in MRSA pathogenesis. Front Microbiol 2023; 14:1204428. [PMID: 37434702 PMCID: PMC10332168 DOI: 10.3389/fmicb.2023.1204428] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/30/2023] [Indexed: 07/13/2023] Open
Abstract
Staphylococcus aureus is one of the most common opportunistic human pathogens causing several infectious diseases. Ever since the emergence of the first methicillin-resistant Staphylococcus aureus (MRSA) strain decades back, the organism has been a major cause of hospital-acquired infections (HA-MRSA). The spread of this pathogen across the community led to the emergence of a more virulent subtype of the strain, i.e., Community acquired Methicillin resistant Staphylococcus aureus (CA-MRSA). Hence, WHO has declared Staphylococcus aureus as a high-priority pathogen. MRSA pathogenesis is remarkable because of the ability of this "superbug" to form robust biofilm both in vivo and in vitro by the formation of polysaccharide intercellular adhesin (PIA), extracellular DNA (eDNA), wall teichoic acids (WTAs), and capsule (CP), which are major components that impart stability to a biofilm. On the other hand, secretion of a diverse array of virulence factors such as hemolysins, leukotoxins, enterotoxins, and Protein A regulated by agr and sae two-component systems (TCS) aids in combating host immune response. The up- and downregulation of adhesion genes involved in biofilm formation and genes responsible for synthesizing virulence factors during different stages of infection act as a genetic regulatory see-saw in the pathogenesis of MRSA. This review provides insight into the evolution and pathogenesis of MRSA infections with a focus on genetic regulation of biofilm formation and virulence factors secretion.
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Affiliation(s)
| | - Seema Rawat
- Microbiology Laboratory, School of Life Sciences, Central University of Gujarat, Gandhinagar, Gujarat, India
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5
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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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6
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Martinez OE, Mahoney BJ, Goring AK, Yi SW, Tran DP, Cascio D, Phillips ML, Muthana MM, Chen X, Jung ME, Loo JA, Clubb RT. Insight into the molecular basis of substrate recognition by the wall teichoic acid glycosyltransferase TagA. J Biol Chem 2021; 298:101464. [PMID: 34864059 PMCID: PMC8784642 DOI: 10.1016/j.jbc.2021.101464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 11/30/2022] Open
Abstract
Wall teichoic acid (WTA) polymers are covalently affixed to the Gram-positive bacterial cell wall and have important functions in cell elongation, cell morphology, biofilm formation, and β-lactam antibiotic resistance. The first committed step in WTA biosynthesis is catalyzed by the TagA glycosyltransferase (also called TarA), a peripheral membrane protein that produces the conserved linkage unit, which joins WTA to the cell wall peptidoglycan. TagA contains a conserved GT26 core domain followed by a C-terminal polypeptide tail that is important for catalysis and membrane binding. Here, we report the crystal structure of the Thermoanaerobacter italicus TagA enzyme bound to UDP-N-acetyl-d-mannosamine, revealing the molecular basis of substrate binding. Native MS experiments support the model that only monomeric TagA is enzymatically active and that it is stabilized by membrane binding. Molecular dynamics simulations and enzyme activity measurements indicate that the C-terminal polypeptide tail facilitates catalysis by encapsulating the UDP-N-acetyl-d-mannosamine substrate, presenting three highly conserved arginine residues to the active site that are important for catalysis (R214, R221, and R224). From these data, we present a mechanistic model of catalysis that ascribes functions for these residues. This work could facilitate the development of new antimicrobial compounds that disrupt WTA biosynthesis in pathogenic bacteria.
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Affiliation(s)
- Orlando E Martinez
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA
| | - Brendan J Mahoney
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA
| | - Andrew K Goring
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA
| | - Sung-Wook Yi
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Denise P Tran
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Duilio Cascio
- UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA
| | - Martin L Phillips
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Musleh M Muthana
- Department of Chemistry, University of California, Davis, California, USA
| | - Xi Chen
- Department of Chemistry, University of California, Davis, California, USA
| | - Michael E Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Joseph A Loo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA.
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7
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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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8
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Wu X, Han J, Gong G, Koffas MAG, Zha J. Wall teichoic acids: physiology and applications. FEMS Microbiol Rev 2020; 45:6019871. [DOI: 10.1093/femsre/fuaa064] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 12/01/2020] [Indexed: 12/21/2022] Open
Abstract
ABSTRACT
Wall teichoic acids (WTAs) are charged glycopolymers containing phosphodiester-linked polyol units and represent one of the major components of Gram-positive cell envelope. WTAs have important physiological functions in cell division, gene transfer, surface adhesion, drug resistance and biofilm formation, and are critical virulence factors and vital determinants in mediating cell interaction with and tolerance to environmental factors. Here, we first briefly introduce WTA structure, biosynthesis and its regulation, and then summarize in detail four major physiological roles played by WTAs, i.e. WTA-mediated resistance to antimicrobials, virulence to mammalian cells, interaction with bacteriolytic enzymes and regulation of cell metabolism. We also review the applications of WTAs in these fields that are closely related to the human society, including antibacterial drug discovery targeting WTA biosynthesis, development of vaccines and antibodies regarding WTA-mediated pathogenicity, specific and sensitive detection of pathogens in food using WTAs as a surface epitope and regulation of WTA-related pathways for efficient microbial production of useful compounds. We also point out major problems remaining in these fields, and discuss some possible directions in the future exploration of WTA physiology and applications.
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Affiliation(s)
- Xia Wu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China
| | - Jing Han
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China
| | - Guoli Gong
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China
| | - Mattheos A G Koffas
- Center for Biotechnology and Interdisciplinary Studies, Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Jian Zha
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi 710021, China
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9
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Hager FF, Sützl L, Stefanović C, Blaukopf M, Schäffer C. Pyruvate Substitutions on Glycoconjugates. Int J Mol Sci 2019; 20:E4929. [PMID: 31590345 PMCID: PMC6801904 DOI: 10.3390/ijms20194929] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 12/15/2022] Open
Abstract
Glycoconjugates are the most diverse biomolecules of life. Mostly located at the cell surface, they translate into cell-specific "barcodes" and offer a vast repertoire of functions, including support of cellular physiology, lifestyle, and pathogenicity. Functions can be fine-tuned by non-carbohydrate modifications on the constituting monosaccharides. Among these modifications is pyruvylation, which is present either in enol or ketal form. The most commonly best-understood example of pyruvylation is enol-pyruvylation of N-acetylglucosamine, which occurs at an early stage in the biosynthesis of the bacterial cell wall component peptidoglycan. Ketal-pyruvylation, in contrast, is present in diverse classes of glycoconjugates, from bacteria to algae to yeast-but not in humans. Mild purification strategies preventing the loss of the acid-labile ketal-pyruvyl group have led to a collection of elucidated pyruvylated glycan structures. However, knowledge of involved pyruvyltransferases creating a ring structure on various monosaccharides is scarce, mainly due to the lack of knowledge of fingerprint motifs of these enzymes and the unavailability of genome sequences of the organisms undergoing pyruvylation. This review compiles the current information on the widespread but under-investigated ketal-pyruvylation of monosaccharides, starting with different classes of pyruvylated glycoconjugates and associated functions, leading to pyruvyltransferases, their specificity and sequence space, and insight into pyruvate analytics.
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Affiliation(s)
- Fiona F Hager
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Leander Sützl
- Department of Food Science and Technology, Food Biotechnology Laboratory, Muthgasse 11, Universität für Bodenkultur Wien, A-1190 Vienna, Austria.
| | - Cordula Stefanović
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
| | - Markus Blaukopf
- Department of Chemistry, Division of Organic Chemistry, Universität für Bodenkultur Wien, Muthgasse 18, A-1190 Vienna, Austria.
| | - Christina Schäffer
- Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, Muthgasse 11, A-1190 Vienna, Austria.
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10
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Structure and mechanism of TagA, a novel membrane-associated glycosyltransferase that produces wall teichoic acids in pathogenic bacteria. PLoS Pathog 2019; 15:e1007723. [PMID: 31002736 PMCID: PMC6493773 DOI: 10.1371/journal.ppat.1007723] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 05/01/2019] [Accepted: 03/21/2019] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus and other bacterial pathogens affix wall teichoic acids (WTAs) to their surface. These highly abundant anionic glycopolymers have critical functions in bacterial physiology and their susceptibility to β-lactam antibiotics. The membrane-associated TagA glycosyltransferase (GT) catalyzes the first-committed step in WTA biosynthesis and is a founding member of the WecB/TagA/CpsF GT family, more than 6,000 enzymes that synthesize a range of extracellular polysaccharides through a poorly understood mechanism. Crystal structures of TagA from T. italicus in its apo- and UDP-bound states reveal a novel GT fold, and coupled with biochemical and cellular data define the mechanism of catalysis. We propose that enzyme activity is regulated by interactions with the bilayer, which trigger a structural change that facilitates proper active site formation and recognition of the enzyme's lipid-linked substrate. These findings inform upon the molecular basis of WecB/TagA/CpsF activity and could guide the development of new anti-microbial drugs.
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11
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Hager FF, López-Guzmán A, Krauter S, Blaukopf M, Polter M, Brockhausen I, Kosma P, Schäffer C. Functional Characterization of Enzymatic Steps Involved in Pyruvylation of Bacterial Secondary Cell Wall Polymer Fragments. Front Microbiol 2018; 9:1356. [PMID: 29997588 PMCID: PMC6030368 DOI: 10.3389/fmicb.2018.01356] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/05/2018] [Indexed: 12/15/2022] Open
Abstract
Various mechanisms of protein cell surface display have evolved during bacterial evolution. Several Gram-positive bacteria employ S-layer homology (SLH) domain-mediated sorting of cell-surface proteins and concomitantly engage a pyruvylated secondary cell-wall polymer as a cell-wall ligand. Specifically, pyruvate ketal linked to β-D-ManNAc is regarded as an indispensable epitope in this cell-surface display mechanism. That secondary cell wall polymer (SCWP) pyruvylation and SLH domain-containing proteins are functionally coupled is supported by the presence of an ortholog of the predicted pyruvyltransferase CsaB in bacterial genomes, such as those of Bacillus anthracis and Paenibacillus alvei. The P. alvei SCWP, consisting of pyruvylated disaccharide repeats [→4)-β-D-GlcNAc-(1→3)-4,6-Pyr-β-D-ManNAc-(1→] serves as a model to investigate the widely unexplored pyruvylation reaction. Here, we reconstituted the underlying enzymatic pathway in vitro in combination with synthesized compounds, used mass spectrometry, and nuclear magnetic resonance spectroscopy for product characterization, and found that CsaB-catalyzed pyruvylation of β-D-ManNAc occurs at the stage of the lipid-linked repeat. We produced the P. alvei TagA (PAV_RS07420) and CsaB (PAV_RS07425) enzymes as recombinant, tagged proteins, and using a synthetic 11-phenoxyundecyl-diphosphoryl-α-GlcNAc acceptor, we uncovered that TagA is an inverting UDP-α-D-ManNAc:GlcNAc-lipid carrier transferase, and that CsaB is a pyruvyltransferase, with synthetic UDP-α-D-ManNAc and phosphoenolpyruvate serving as donor substrates. Next, to substitute for the UDP-α-D-ManNAc substrate, the recombinant UDP-GlcNAc-2-epimerase MnaA (PAV_RS07610) of P. alvei was included in this in vitro reconstitution system. When all three enzymes, their substrates and the lipid-linked GlcNAc primer were combined in a one-pot reaction, a lipid-linked SCWP repeat precursor analog was obtained. This work highlights the biochemical basis of SCWP biosynthesis and bacterial pyruvyl transfer.
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Affiliation(s)
- Fiona F Hager
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Arturo López-Guzmán
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Simon Krauter
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Markus Blaukopf
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Mathias Polter
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
| | - Inka Brockhausen
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Paul Kosma
- Division of Organic Chemistry, Department of Chemistry, Universität für Bodenkultur Wien, Vienna, Austria
| | - Christina Schäffer
- NanoGlycobiology Unit, Department of NanoBiotechnology, Universität für Bodenkultur Wien, Vienna, Austria
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12
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Zhang L, Muthana MM, Yu H, McArthur JB, Qu J, Chen X. Characterizing non-hydrolyzing Neisseria meningitidis serogroup A UDP-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase using UDP-N-acetylmannosamine (UDP-ManNAc) and derivatives. Carbohydr Res 2015; 419:18-28. [PMID: 26598987 DOI: 10.1016/j.carres.2015.10.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 11/28/2022]
Abstract
Neisseria meningitidis serogroup A non-hydrolyzing uridine 5'-diphosphate-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase (NmSacA) catalyzes the interconversion between UDP-GlcNAc and uridine 5'-diphosphate-N-acetylmannosamine (UDP-ManNAc). It is a key enzyme involved in the biosynthesis of the capsular polysaccharide [-6ManNAcα1-phosphate-]n of N. meningitidis serogroup A, one of the six serogroups (A, B, C, W-135, X, and Y) that account for most cases of N. meningitidis-caused bacterial septicemia and meningitis. N. meningitidis serogroup A is responsible for large epidemics in the developing world, especially in Africa. Here we report that UDP-ManNAc could be used as a substrate for C-terminal His6-tagged recombinant NmSacA (NmSacA-His6) in the absence of UDP-GlcNAc. NmSacA-His6 was activated by UDP-GlcNAc and inhibited by 2-acetamidoglucal and UDP. Substrate specificity study showed that NmSacA-His6 could tolerate several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates although its activity was much lower than non-modified UDP-ManNAc. Homology modeling and molecular docking revealed likely structural determinants of NmSacA substrate specificity. This is the first detailed study of N. meningitidis serogroup A UDP-GlcNAc 2-epimerase.
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Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Musleh M Muthana
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Hai Yu
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - John B McArthur
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Jingyao Qu
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Xi Chen
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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13
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Gale RT, Brown ED. New chemical tools to probe cell wall biosynthesis in bacteria. Curr Opin Microbiol 2015; 27:69-77. [PMID: 26291270 DOI: 10.1016/j.mib.2015.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/23/2015] [Accepted: 07/30/2015] [Indexed: 12/25/2022]
Abstract
Some of the most successful drugs in the antibiotic pharmacopeia are those that inhibit bacterial cell wall biosynthesis. However, the worldwide spread of bacterial antibiotic resistance has eroded the clinical efficacy of these drugs and the antibiotic pipeline continues to be lean as drug discovery programs struggle to bring new agents to the clinic. Nevertheless, cell wall biogenesis remains a high interest and celebrated target. Recent advances in the preparation of chemical probes and biosynthetic intermediates provide the tools necessary to better understand cell wall assembly. Likewise, these tools offer new opportunities to identify and evaluate novel biosynthetic inhibitors. This review aims to highlight these advancements and to provide context for their utility as innovative new tools to study cell wall biogenesis and for antibacterial drug discovery.
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Affiliation(s)
- Robert T Gale
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada L8N 3Z5
| | - Eric D Brown
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada L8N 3Z5.
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14
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Taylor VL, Huszczynski SM, Lam JS. Membrane Translocation and Assembly of Sugar Polymer Precursors. Curr Top Microbiol Immunol 2015; 404:95-128. [PMID: 26853690 DOI: 10.1007/82_2015_5014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bacterial polysaccharides play an essential role in cell viability, virulence, and evasion of host defenses. Although the polysaccharides themselves are highly diverse, the pathways by which bacteria synthesize these essential polymers are conserved in both Gram-negative and Gram-positive organisms. By utilizing a lipid linker, a series of glycosyltransferases and integral membrane proteins act in concert to synthesize capsular polysaccharide, teichoic acid, and teichuronic acid. The pathways used to produce these molecules are the Wzx/Wzy-dependent, the ABC-transporter-dependent, and the synthase-dependent pathways. This chapter will cover the initiation, synthesis of the various polysaccharides on the cytoplasmic face of the membrane using nucleotide sugar precursors, and export of the nascent chain from the cytoplasm to the extracellular milieu. As microbial glycobiology is an emerging field in Gram-positive bacteria research, parallels will be drawn to the more widely studied polysaccharide biosynthesis systems in Gram-negative species in order to provide greater understanding of these biologically significant molecules.
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Affiliation(s)
- Véronique L Taylor
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Steven M Huszczynski
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Joseph S Lam
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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15
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16
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Weidenmaier C, Lee JC. Structure and Function of Surface Polysaccharides of Staphylococcus aureus. Curr Top Microbiol Immunol 2015; 409:57-93. [PMID: 26728067 DOI: 10.1007/82_2015_5018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The major surface polysaccharides of Staphylococcus aureus include the capsular polysaccharide (CP), cell wall teichoic acid (WTA), and polysaccharide intercellular adhesin/poly-β(1-6)-N-acetylglucosamine (PIA/PNAG). These glycopolymers are important components of the staphylococcal cell envelope, but none of them is essential to S. aureus viability and growth in vitro. The overall biosynthetic pathways of CP, WTA, and PIA/PNAG have been elucidated, and the functions of most of the biosynthetic enzymes have been demonstrated. Because S. aureus CP and WTA (but not PIA/PNAG) utilize a common cell membrane lipid carrier (undecaprenyl-phosphate) that is shared by the peptidoglycan biosynthesis pathway, there is evidence that these processes are highly integrated and temporally regulated. Regulatory elements that control glycopolymer biosynthesis have been described, but the cross talk that orchestrates the biosynthetic pathways of these three polysaccharides remains largely elusive. CP, WTA, and PIA/PNAG each play distinct roles in S. aureus colonization and the pathogenesis of staphylococcal infection. However, they each promote bacterial evasion of the host immune defences, and WTA is being explored as a target for antimicrobial therapeutics. All the three glycopolymers are viable targets for immunotherapy, and each (conjugated to a carrier protein) is under evaluation for inclusion in a multivalent S. aureus vaccine. Future research findings that increase our understanding of these surface polysaccharides, how the bacterial cell regulates their expression, and their biological functions will likely reveal new approaches to controlling this important bacterial pathogen.
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Affiliation(s)
- Christopher Weidenmaier
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen and German Center for Infection Research, Tübingen, Germany
| | - Jean C Lee
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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17
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Gale RT, Sewell EW, Garrett TA, Brown ED. Reconstituting poly(glycerol phosphate) wall teichoic acid biosynthesis in vitro using authentic substrates. Chem Sci 2014. [DOI: 10.1039/c4sc00802b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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18
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Misra S, Sharma V, Srivastava AK. Bacterial Polysaccharides: An Overview. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_68-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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19
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Sewell EWC, Brown ED. Taking aim at wall teichoic acid synthesis: new biology and new leads for antibiotics. J Antibiot (Tokyo) 2013; 67:43-51. [PMID: 24169797 DOI: 10.1038/ja.2013.100] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 09/04/2013] [Accepted: 09/10/2013] [Indexed: 11/09/2022]
Abstract
Wall teichoic acids are a major and integral component of the Gram-positive cell wall. These structures are present across all species of Gram-positive bacteria and constitute roughly half of the cell wall. Despite decades of careful investigation, a definitive physiological function for wall teichoic acids remains elusive. Advances in the genetics and biochemistry of wall teichoic acid synthesis have led to a new understanding of the complexity of cell wall synthesis in Gram-positive bacteria. Indeed, these innovations have provided new molecular tools available to probe the synthesis and function of these cell wall structures. Among recent discoveries are unexpected roles for wall teichoic acid in cell division, coordination of peptidoglycan synthesis and β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA). Notably, wall teichoic acid biogenesis has emerged as a bona fide drug target in S. aureus, where remarkable synthetic-viable interactions among biosynthetic genes have been leveraged for the discovery and characterization of novel inhibitors of the pathway.
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Affiliation(s)
- Edward W C Sewell
- Michael G DeGroote Institute for Infectious Disease Research and the Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Eric D Brown
- Michael G DeGroote Institute for Infectious Disease Research and the Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
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20
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Abstract
The peptidoglycan layers of many gram-positive bacteria are densely functionalized with anionic glycopolymers known as wall teichoic acids (WTAs). These polymers play crucial roles in cell shape determination, regulation of cell division, and other fundamental aspects of gram-positive bacterial physiology. Additionally, WTAs are important in pathogenesis and play key roles in antibiotic resistance. We provide an overview of WTA structure and biosynthesis, review recent studies on the biological roles of these polymers, and highlight remaining questions. We also discuss prospects for exploiting WTA biosynthesis as a target for new therapies to overcome resistant infections.
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Affiliation(s)
- Stephanie Brown
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115;
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21
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Muthana MM, Qu J, Li Y, Zhang L, Yu H, Ding L, Malekan H, Chen X. Efficient one-pot multienzyme synthesis of UDP-sugars using a promiscuous UDP-sugar pyrophosphorylase from Bifidobacterium longum (BLUSP). Chem Commun (Camb) 2012; 48:2728-30. [PMID: 22306833 DOI: 10.1039/c2cc17577k] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A promiscuous UDP-sugar pyrophosphorylase (BLUSP) was cloned from Bifidobacterium longum strain ATCC55813 and used efficiently with a Pasteurella multocida inorganic pyrophosphatase (PmPpA) with or without a monosaccharide 1-kinase for one-pot multienzyme synthesis of UDP-galactose, UDP-glucose, UDP-mannose, and their derivatives. Further chemical diversification of a UDP-mannose derivative resulted in the formation of UDP-N-acetylmannosamine.
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Affiliation(s)
- Musleh M Muthana
- Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA
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22
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Lee HJ, Lairson LL, Rich JR, Lameignere E, Wakarchuk WW, Withers SG, Strynadka NCJ. Structural and kinetic analysis of substrate binding to the sialyltransferase Cst-II from Campylobacter jejuni. J Biol Chem 2011; 286:35922-35932. [PMID: 21832050 DOI: 10.1074/jbc.m111.261172] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sialic acids play important roles in various biological processes and typically terminate the oligosaccharide chains on the cell surfaces of a wide range of organisms, including mammals and bacteria. Their attachment is catalyzed by a set of sialyltransferases with defined specificities both for their acceptor sugars and the position of attachment. However, little is known of how this specificity is encoded. The structure of the bifunctional sialyltransferase Cst-II of the human pathogen Campylobacter jejuni in complex with CMP and the terminal trisaccharide of its natural acceptor (Neu5Ac-α-2,3-Gal-β-1,3-GalNAc) has been solved at 1.95 Å resolution, and its kinetic mechanism was shown to be iso-ordered Bi Bi, consistent with its dual acceptor substrate specificity. The trisaccharide acceptor is seen to bind to the active site of Cst-II through interactions primarily mediated by Asn-51, Tyr-81, and Arg-129. Kinetic and structural analyses of mutants modified at these positions indicate that these residues are critical for acceptor binding and catalysis, thereby providing significant new insight into the kinetic and catalytic mechanism, and acceptor specificity of this pathogen-encoded bifunctional GT-42 sialyltransferase.
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Affiliation(s)
- Ho Jun Lee
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3; Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3
| | - Luke L Lairson
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1
| | - Jamie R Rich
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1
| | - Emilie Lameignere
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3; Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3
| | - Warren W Wakarchuk
- Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Stephen G Withers
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3; Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1; Centre for High-Throughput Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3; Centre for Blood Research, University of British Columbia, Vancouver, British Columbia V6T 1Z3; Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4.
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23
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Allison SE, D'Elia MA, Arar S, Monteiro MA, Brown ED. Studies of the genetics, function, and kinetic mechanism of TagE, the wall teichoic acid glycosyltransferase in Bacillus subtilis 168. J Biol Chem 2011; 286:23708-16. [PMID: 21558268 DOI: 10.1074/jbc.m111.241265] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The biosynthetic enzymes involved in wall teichoic acid biogenesis in gram-positive bacteria have been the subject of renewed investigation in recent years with the benefit of modern tools of biochemistry and genetics. Nevertheless, there have been only limited investigations into the enzymes that glycosylate wall teichoic acid. Decades-old experiments in the model gram-positive bacterium, Bacillus subtilis 168, using phage-resistant mutants implicated tagE (also called gtaA and rodD) as the gene coding for the wall teichoic acid glycosyltransferase. This study and others have provided only indirect evidence to support a role for TagE in wall teichoic acid glycosylation. In this work, we showed that deletion of tagE resulted in the loss of α-glucose at the C-2 position of glycerol in the poly(glycerol phosphate) polymer backbone. We also reported the first kinetic characterization of pure, recombinant wall teichoic acid glycosyltransferase using clean synthetic substrates. We investigated the substrate specificity of TagE using a wide variety of acceptor substrates and found that the enzyme had a strong kinetic preference for the transfer of glucose from UDP-glucose to glycerol phosphate in polymeric form. Further, we showed that the enzyme recognized its polymeric (and repetitive) substrate with a sequential kinetic mechanism. This work provides direct evidence that TagE is the wall teichoic acid glycosyltransferase in B. subtilis 168 and provides a strong basis for further studies of the mechanism of wall teichoic acid glycosylation, a largely uncharted aspect of wall teichoic acid biogenesis.
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Affiliation(s)
- Sarah E Allison
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
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24
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Salinas SR, Bianco MI, Barreras M, Ielpi L. Expression, purification and biochemical characterization of GumI, a monotopic membrane GDP-mannose:glycolipid 4-{beta}-D-mannosyltransferase from Xanthomonas campestris pv. campestris. Glycobiology 2011; 21:903-13. [PMID: 21367879 DOI: 10.1093/glycob/cwr022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We describe the first biochemical characterization of the gumI gene product, an essential protein for xanthan polysaccharide synthesis. Cellular fractionation experiments reveal the presence of a protein associated with the membrane fraction, even in the absence of the other proteins responsible for the synthesis of glycolipid intermediates and the proteins involved in the polymerization and transport of the xanthan chains. By alkaline buffer extraction and detergent phase partitioning, GumI was categorized as a monotopic membrane protein. GumI was overexpressed in Escherichia coli, solubilized and purified in an active and stable form using a simple and reproducible two-step procedure. The purified recombinant GumI is a nonprocessive β-mannosyltransferase that uses GDP-Man as a donor substrate and glucuronic acid-β-1,2-mannose-α-1,3-glucose-β-1,4-glucose-PP-polyisoprenyl as an acceptor. We also established the optimal biochemical conditions for GumI enzymatic activity. Sequence analysis revealed the presence of a conserved domain for glycosyltransferases (GTs) of the GT-B superfamily and homologous proteins in several prokaryote organisms. On the basis of this biochemical characterization, GumI may represent the founding member of a new GT family in the Carbohydrate-Active EnZymes classification.
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Affiliation(s)
- Silvina R Salinas
- Laboratory of Bacterial Genetics, Fundación Instituto Leloir, IIBBA-CONICET, C1405BWE Buenos Aires, Argentina
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25
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Staphylococcus aureus and Bacillus subtilis W23 make polyribitol wall teichoic acids using different enzymatic pathways. ACTA ACUST UNITED AC 2011; 17:1101-10. [PMID: 21035733 DOI: 10.1016/j.chembiol.2010.07.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 05/17/2010] [Accepted: 07/16/2010] [Indexed: 12/22/2022]
Abstract
Wall teichoic acids (WTAs) are anionic polymers that play key roles in bacterial cell shape, cell division, envelope integrity, biofilm formation, and pathogenesis. B. subtilis W23 and S. aureus both make polyribitol-phosphate (RboP) WTAs and contain similar sets of biosynthetic genes. We use in vitro reconstitution combined with genetics to show that the pathways for WTA biosynthesis in B. subtilis W23 and S. aureus are different. S. aureus requires a glycerol-phosphate primase called TarF in order to make RboP-WTAs; B. subtilis W23 contains a TarF homolog, but this enzyme makes glycerol-phosphate polymers and is not involved in RboP-WTA synthesis. Instead, B. subtilis TarK functions in place of TarF to prime the WTA intermediate for chain extension by TarL. This work highlights the enzymatic diversity of the poorly characterized family of phosphotransferases involved in WTA biosynthesis in Gram-positive organisms.
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26
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Swoboda JG, Campbell J, Meredith TC, Walker S. Wall teichoic acid function, biosynthesis, and inhibition. Chembiochem 2010; 11:35-45. [PMID: 19899094 DOI: 10.1002/cbic.200900557] [Citation(s) in RCA: 277] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Jonathan G Swoboda
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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27
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Perlstein DL, Wang TSA, Doud EH, Kahne D, Walker S. The role of the substrate lipid in processive glycan polymerization by the peptidoglycan glycosyltransferases. J Am Chem Soc 2010; 132:48-9. [PMID: 20017480 DOI: 10.1021/ja909325m] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The peptidoglycan glycosyltransferases (PGTs) catalyze the processive polymerization of a C55 lipid-linked disaccharide (Lipid II) to form peptidoglycan, the main component of the bacterial cell wall. Our ability to understand this reaction has been limited due to challenges identifying the appropriate substrate analogues to selectively interrogate the donor (the elongating strand) and acceptor (Lipid II) sites. To address this problem, we have developed an assay using synthetic substrates that can discriminate between the donor and acceptor sites of the PGTs. We have shown that each site has a distinct lipid length preference. We have also established that processive polymerization depends on the length of the lipid attached to the donor.
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Affiliation(s)
- Deborah L Perlstein
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
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28
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Garimella R, Halye JL, Harrison W, Klebba PE, Rice CV. Conformation of the phosphate D-alanine zwitterion in bacterial teichoic acid from nuclear magnetic resonance spectroscopy. Biochemistry 2009; 48:9242-9. [PMID: 19746945 PMCID: PMC4196936 DOI: 10.1021/bi900503k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformation of d-alanine (d-Ala) groups of bacterial teichoic acid is a central, yet untested, paradigm of microbiology. The d-Ala binds via the C-terminus, thereby allowing the amine to exist as a free cationic NH(3)(+) group with the ability to form a contact ion pair with the nearby anionic phosphate group. This conformation hinders metal chelation by the phosphate because the zwitterion pair is charge neutral. To the contrary, the repulsion of cationic antimicrobial peptides (CAMPs) is attributed to the presence of the d-Ala cation; thus the ion pair does not form in this model. Solid-state nuclear magnetic resonance (NMR) spectroscopy has been used to measure the distance between amine and phosphate groups within cell wall fragments of Bacillus subtilis. The bacteria were grown on media containing (15)N d-Ala and beta-chloroalanine racemase inhibitor. The rotational-echo double-resonance (REDOR) pulse sequence was used to measure the internuclear dipolar coupling, and the results demonstrate (1) the metal-free amine-to-phosphate distance is 4.4 A and (2) the amine-to-phosphate distance increases to 5.4 A in the presence of Mg(2+) ions. As a result, the zwitterion exists in a nitrogen-oxygen ion pair configuration providing teichoic acid with a positive charge to repel CAMPs. Additionally, the amine of d-Ala does not prevent magnesium chelation in contradiction to the prevailing view of teichoic acids in metal binding. Thus, the NMR-based description of teichoic acid structure resolves the contradictory models, advances the basic understanding of cell wall biochemistry, and provides possible insight into the creation of new antibiotic therapies.
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Affiliation(s)
- Ravindranath Garimella
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
| | - Jeffrey L. Halye
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
| | - William Harrison
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
| | - Phillip E. Klebba
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
| | - Charles V. Rice
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Room 208, Norman, OK 73019
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29
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Falconer SB, Brown ED. New screens and targets in antibacterial drug discovery. Curr Opin Microbiol 2009; 12:497-504. [DOI: 10.1016/j.mib.2009.07.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 06/30/2009] [Accepted: 07/06/2009] [Indexed: 11/15/2022]
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30
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Sewell EWC, Pereira MP, Brown ED. The wall teichoic acid polymerase TagF is non-processive in vitro and amenable to study using steady state kinetic analysis. J Biol Chem 2009; 284:21132-8. [PMID: 19520862 DOI: 10.1074/jbc.m109.010215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Wall teichoic acids are a chemically diverse group of anionic polymers that constitute up to 50% of the Gram-positive cell wall. These polymers play a pivotal role in virulence and have been implicated in a diverse range of physiological functions. The TagF-like family of enzymes has been shown to be responsible for wall teichoic acid priming and polymerization events. Although many such enzymes are well validated therapeutic targets, a mechanistic understanding of this enzyme family has remained elusive. TagF is the prototypical teichoic acid polymerase and uses CDP-glycerol to catalyze synthesis of the linear (1,3)-linked poly(glycerol phosphate) teichoic acid in Bacillus subtilis 168. Here we used a synthetic soluble analog of the natural substrate of the enzyme, Lipid , to conduct the first detailed mechanistic investigation of teichoic acid polymerization. Through the use of a new high pressure liquid chromatography-based assay to monitor single glycerol phosphate incorporations into the Lipid analog, we conducted a detailed analysis of reaction product formation patterns and unequivocally showed TagF to be non-processive in vitro. Furthermore by monitoring the kinetics of polymerization, we showed that Lipid analog species varying in size have the same K(m) value of 2.6 microm and validated use of Bi Bi velocity expressions to model the TagF enzyme system. Initial rate analysis showed that TagF catalyzes a sequential Bi Bi mechanism where both substrates are added to the enzyme prior to product release consistent with a single displacement chemical mechanism.
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Affiliation(s)
- Edward W C Sewell
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
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31
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The N-acetylmannosamine transferase catalyzes the first committed step of teichoic acid assembly in Bacillus subtilis and Staphylococcus aureus. J Bacteriol 2009; 191:4030-4. [PMID: 19376878 DOI: 10.1128/jb.00611-08] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There have been considerable strides made in the characterization of the dispensability of teichoic acid biosynthesis genes in recent years. A notable omission thus far has been an early gene in teichoic acid synthesis encoding the N-acetylmannosamine transferase (tagA in Bacillus subtilis; tarA in Staphylococcus aureus), which adds N-acetylmannosamine to complete the synthesis of undecaprenol pyrophosphate-linked disaccharide. Here, we show that the N-acetylmannosamine transferases are dispensable for growth in vitro, making this biosynthetic enzyme the last dispensable gene in the pathway, suggesting that tagA (or tarA) encodes the first committed step in wall teichoic acid synthesis.
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Grzegorzewicz AE, Ma Y, Jones V, Crick D, Liav A, McNeil MR. Development of a microtitre plate-based assay for lipid-linked glycosyltransferase products using the mycobacterial cell wall rhamnosyltransferase WbbL. MICROBIOLOGY-SGM 2009; 154:3724-3730. [PMID: 19047740 DOI: 10.1099/mic.0.2008/023366-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Mycobacterium tuberculosis a rhamnosyltransferase (WbbL) catalyses the transfer of an alpha-L-Rhap residue from dTDP-L-rhamnose (dTDP-Rha) to decaprenyldiphosphoryl-alpha-D-N-acetylglucosamine (GlcNAc-P-P-DP) to form alpha-L-Rhap-(1-->3)-alpha-D-GlcNAc-P-P-DP, which is then further elongated with Galf and Araf units, and finally mycolylated and attached to the peptidoglycan. This enzyme is essential for M. tuberculosis viability and at the same time absent in eukaryotic cells, and is therefore a good target for the development of new antituberculosis therapeutics. Here, we report a microtitre plate-based method for the assay of this enzyme using a crude membrane preparation from an Escherichia coli strain overexpressing wbbL as an enzyme source and the natural acceptor substrate GlcNAc-P-P-DP. Initial characterization of the enzyme included unequivocal identification of the product Rha-GlcNAc-P-P-DP by liquid chromatography (LC)-MS, and the facts that WbbL shows an absolute requirement for divalent cations and that its activity is stimulated by beta-mercaptoethanol. Its pH optimum and basic kinetic parameters were also determined, and the kinetic analysis showed that WbbL uses a ternary complex mechanism. The microtitre plate-based assay for this enzyme was developed by taking advantage of the lipophilic nature of the product. This assay should be readily transferable to other glycosyltransferases which use lipid-based acceptors and aid greatly in obtaining inhibitors of such glycosyltransferases for new drug development.
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Affiliation(s)
- Anna E Grzegorzewicz
- Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
| | - Yufang Ma
- Dalian Medical University, Dalian, PR China.,Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
| | - Victoria Jones
- Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
| | - Dean Crick
- Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
| | - Avraham Liav
- Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
| | - Michael R McNeil
- Department of Microbiology, Colorado State University, Fort Collins, CO 80523, USA
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Pereira MP, Schertzer JW, D'Elia MA, Koteva KP, Hughes DW, Wright GD, Brown ED. The Wall Teichoic Acid Polymerase TagF Efficiently Synthesizes Poly(glycerol phosphate) on the TagB Product Lipid III. Chembiochem 2008; 9:1385-90. [DOI: 10.1002/cbic.200800026] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brockhausen I, Riley JG, Joynt M, Yang X, Szarek WA. Acceptor substrate specificity of UDP-Gal: GlcNAc-R β1,3-galactosyltransferase (WbbD) from Escherichia coli O7:K1. Glycoconj J 2008; 25:663-73. [DOI: 10.1007/s10719-008-9127-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 03/18/2008] [Accepted: 03/20/2008] [Indexed: 10/22/2022]
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Brown S, Zhang YH, Walker S. A revised pathway proposed for Staphylococcus aureus wall teichoic acid biosynthesis based on in vitro reconstitution of the intracellular steps. ACTA ACUST UNITED AC 2008; 15:12-21. [PMID: 18215769 DOI: 10.1016/j.chembiol.2007.11.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Revised: 11/09/2007] [Accepted: 11/14/2007] [Indexed: 11/15/2022]
Abstract
Resistance to every family of clinically used antibiotics has emerged, and there is a pressing need to explore unique antibacterial targets. Wall teichoic acids (WTAs) are anionic polymers that coat the cell walls of many Gram-positive bacteria. Because WTAs play an essential role in Staphylococcus aureus colonization and infection, the enzymes involved in WTA biosynthesis are proposed to be targets for antibiotic development. To facilitate the discovery of WTA inhibitors, we have reconstituted the intracellular steps of S. aureus WTA biosynthesis. We show that two intracellular steps in the biosynthetic pathway are different from what was proposed. The work reported here lays the foundation for the discovery and characterization of inhibitors of WTA biosynthetic enzymes to assess their potential for treating bacterial infections.
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Affiliation(s)
- Stephanie Brown
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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