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Durand T, Dodge GJ, Siuda RP, Higinbotham HR, Arbour CA, Ghosh S, Allen KN, Imperiali B. Proteome-Wide Bioinformatic Annotation and Functional Validation of the Monotopic Phosphoglycosyl Transferase Superfamily. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.10.602977. [PMID: 39026775 PMCID: PMC11257628 DOI: 10.1101/2024.07.10.602977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Phosphoglycosyl transferases (PGTs) are membrane proteins that initiate glycoconjugate biosynthesis by transferring a phospho-sugar moiety from a soluble nucleoside diphosphate sugar to a membrane-embedded polyprenol phosphate acceptor. The centrality of PGTs in complex glycan assembly and the current lack of functional information make these enzymes high-value targets for biochemical investigation. In particular, the small monotopic PGT family is exclusively bacterial and represents the minimal functional unit of the monotopic PGT superfamily. Here, we combine a sequence similarity network (SSN) analysis with a generalizable, luminescence-based activity assay to probe the substrate specificity of this family of monoPGTs in a bacterial cell-membrane fraction. This strategy allows us to identify specificity on a far more significant scale than previously achievable and correlate preferred substrate specificities with predicted structural differences within the conserved monoPGT fold. Finally, we present the proof-of-concept for a small-scale inhibitor screen (eight nucleoside analogs) with four monoPGTs of diverse substrate specificity, thus building a foundation for future inhibitor discovery initiatives.
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Affiliation(s)
- Theo Durand
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Imperial College London, Exhibition Rd, South Kensington, London SW7 2AZ, UK
| | - Greg J. Dodge
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Current address Biogen, 225 Binney Street, Cambridge MA 02139, USA
| | - Roxanne P. Siuda
- Department of Chemistry, Boston University, 590 Commonwealth Ave, Boston MA 02215, USA
- Dept. of Pharmacology Physiology, and Biophysics, Boston University Chobanian & Avedisian School of Medicine, 72 E Concord St L-630D, Boston, MA 02215, USA
| | - Hugh R. Higinbotham
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christine A. Arbour
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Soumi Ghosh
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Karen N. Allen
- Department of Chemistry, Boston University, 590 Commonwealth Ave, Boston MA 02215, USA
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Dodge GJ, Anderson AJ, He Y, Liu W, Viner R, Imperiali B. Mapping the architecture of the initiating phosphoglycosyl transferase from S. enterica O-antigen biosynthesis in a liponanoparticle. eLife 2024; 12:RP91125. [PMID: 38358918 PMCID: PMC10942596 DOI: 10.7554/elife.91125] [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] [Indexed: 02/17/2024] Open
Abstract
Bacterial cell surface glycoconjugates are critical for cell survival and for interactions between bacteria and their hosts. Consequently, the pathways responsible for their biosynthesis have untapped potential as therapeutic targets. The localization of many glycoconjugate biosynthesis enzymes to the membrane represents a significant challenge for expressing, purifying, and characterizing these enzymes. Here, we leverage cutting-edge detergent-free methods to stabilize, purify, and structurally characterize WbaP, a phosphoglycosyl transferase (PGT) from the Salmonella enterica (LT2) O-antigen biosynthesis. From a functional perspective, these studies establish WbaP as a homodimer, reveal the structural elements responsible for dimerization, shed light on the regulatory role of a domain of unknown function embedded within WbaP, and identify conserved structural motifs between PGTs and functionally unrelated UDP-sugar dehydratases. From a technological perspective, the strategy developed here is generalizable and provides a toolkit for studying other classes of small membrane proteins embedded in liponanoparticles beyond PGTs.
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Affiliation(s)
- Greg J Dodge
- Department of Biology and Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Alyssa J Anderson
- Department of Biology and Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Yi He
- Thermo Fisher ScientificSan JoseUnited States
| | - Weijing Liu
- Thermo Fisher ScientificSan JoseUnited States
| | - Rosa Viner
- Thermo Fisher ScientificSan JoseUnited States
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of TechnologyCambridgeUnited States
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3
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Seebald LM, Haratipour P, Jacobs MR, Bernstein HM, Kashemirov BA, McKenna CE, Imperiali B. Uridine Bisphosphonates Differentiate Phosphoglycosyl Transferase Superfamilies. J Am Chem Soc 2024; 146:3220-3229. [PMID: 38271668 PMCID: PMC10922802 DOI: 10.1021/jacs.3c11402] [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] [Indexed: 01/27/2024]
Abstract
Complex bacterial glycoconjugates drive interactions between pathogens, symbionts, and their human hosts. Glycoconjugate biosynthesis is initiated at the membrane interface by phosphoglycosyl transferases (PGTs), which catalyze the transfer of a phosphosugar from a soluble uridine diphosphosugar (UDP-sugar) substrate to a membrane-bound polyprenol-phosphate (Pren-P). The two distinct superfamilies of PGT enzymes (polytopic and monotopic) show striking differences in their structure and mechanism. We designed and synthesized a series of uridine bisphosphonates (UBPs), wherein the diphosphate of the UDP and UDP-sugar is replaced by a substituted methylene bisphosphonate (CXY-BPs; X/Y = F/F, Cl/Cl, (S)-H/F, (R)-H/F, H/H, CH3/CH3). UBPs and UBPs incorporating an N-acetylglucosamine (GlcNAc) substituent at the β-phosphonate were evaluated as inhibitors of a polytopic PGT (WecA from Thermotoga maritima) and a monotopic PGT (PglC from Campylobacter jejuni). Although CHF-BP most closely mimics diphosphate with respect to its acid/base properties, the less basic CF2-BP conjugate more strongly inhibited PglC, whereas the more basic CH2-BP analogue was the strongest inhibitor of WecA. These surprising differences indicate different modes of ligand binding for the different PGT superfamilies, implicating a modified P-O- interaction with the structural Mg2+. For the monoPGT enzyme, the two diastereomeric CHF-BP conjugates, which feature a chiral center at the Pα-CHF-Pβ carbon, also exhibited strikingly different binding affinities and the inclusion of GlcNAc with the native α-anomer configuration significantly improved binding affinity. UBP-sugars are thus revealed as informative new mechanistic probes of PGTs that may aid development of novel antibiotic agents for the exclusively prokaryotic monoPGT superfamily.
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Affiliation(s)
- Leah M. Seebald
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Pouya Haratipour
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Michaela R. Jacobs
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Hannah M. Bernstein
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Boris A. Kashemirov
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Arbour CA, Nagar R, Bernstein HM, Ghosh S, Al-Sammarraie Y, Dorfmueller HC, Ferguson MAJ, Stanley-Wall NR, Imperiali B. Defining early steps in Bacillus subtilis biofilm biosynthesis. mBio 2023; 14:e0094823. [PMID: 37650625 PMCID: PMC10653937 DOI: 10.1128/mbio.00948-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/08/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE Biofilms are the communal way of life that microbes adopt to increase survival. Key to our ability to systematically promote or ablate biofilm formation is a detailed understanding of the biofilm matrix macromolecules. Here, we identify the first two essential steps in the Bacillus subtilis biofilm matrix exopolysaccharide (EPS) synthesis pathway. Together, our studies and approaches provide the foundation for the sequential characterization of the steps in EPS biosynthesis, using prior steps to enable chemoenzymatic synthesis of the undecaprenyl diphosphate-linked glycan substrates.
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Affiliation(s)
- Christine A. Arbour
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Rupa Nagar
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Hannah M. Bernstein
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Soumi Ghosh
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Yusra Al-Sammarraie
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Helge C. Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael A. J. Ferguson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Nicola R. Stanley-Wall
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Majumder A, Vuksanovic N, Ray LC, Bernstein HM, Allen KN, Imperiali B, Straub JE. Synergistic computational and experimental studies of a phosphoglycosyl transferase membrane/ligand ensemble. J Biol Chem 2023; 299:105194. [PMID: 37633332 PMCID: PMC10519829 DOI: 10.1016/j.jbc.2023.105194] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/18/2023] [Accepted: 08/20/2023] [Indexed: 08/28/2023] Open
Abstract
Complex glycans serve essential functions in all living systems. Many of these intricate and byzantine biomolecules are assembled employing biosynthetic pathways wherein the constituent enzymes are membrane-associated. A signature feature of the stepwise assembly processes is the essentiality of unusual linear long-chain polyprenol phosphate-linked substrates of specific isoprene unit geometry, such as undecaprenol phosphate (UndP) in bacteria. How these enzymes and substrates interact within a lipid bilayer needs further investigation. Here, we focus on a small enzyme, PglC from Campylobacter, structurally characterized for the first time in 2018 as a detergent-solubilized construct. PglC is a monotopic phosphoglycosyl transferase that embodies the functional core structure of the entire enzyme superfamily and catalyzes the first membrane-committed step in a glycoprotein assembly pathway. The size of the enzyme is significant as it enables high-level computation and relatively facile, for a membrane protein, experimental analysis. Our ensemble computational and experimental results provided a high-level view of the membrane-embedded PglC/UndP complex. The findings suggested that it is advantageous for the polyprenol phosphate to adopt a conformation in the same leaflet where the monotopic membrane protein resides as opposed to additionally disrupting the opposing leaflet of the bilayer. Further, the analysis showed that electrostatic steering acts as a major driving force contributing to the recognition and binding of both UndP and the soluble nucleotide sugar substrate. Iterative computational and experimental mutagenesis support a specific interaction of UndP with phosphoglycosyl transferase cationic residues and suggest a role for critical conformational transitions in substrate binding and specificity.
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Affiliation(s)
- Ayan Majumder
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
| | | | - Leah C Ray
- Program in Biomolecular Pharmacology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Hannah M Bernstein
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Karen N Allen
- Department of Chemistry, Boston University, Boston, Massachusetts, USA; Program in Biomolecular Pharmacology, Boston University School of Medicine, Boston, Massachusetts, USA.
| | - Barbara Imperiali
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - John E Straub
- Department of Chemistry, Boston University, Boston, Massachusetts, USA.
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Seebald LM, Haratipour P, Jacobs MR, Bernstein HM, Kashemirov BA, McKenna CE, Imperiali B. Uridine Bisphosphonates Differentiate Phosphoglycosyl Transferase Superfamilies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.19.558431. [PMID: 37786673 PMCID: PMC10541605 DOI: 10.1101/2023.09.19.558431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Complex bacterial glycoconjugates are essential for bacterial survival, and drive interactions between pathogens and symbionts, and their human hosts. Glycoconjugate biosynthesis is initiated at the membrane interface by phosphoglycosyl transferases (PGTs), which catalyze the transfer of a phosphosugar from a soluble uridine diphospho-sugar (UDP-sugar) substrate to a membrane-bound polyprenol-phosphate (Pren-P). Two distinct superfamilies of PGT enzymes, denoted as polytopic and monotopic, carry out this reaction but show striking differences in structure and mechanism. With the goal of creating non-hydrolyzable mimics (UBP-sugars) of the UDP-sugar substrates as chemical probes to interrogate critical aspects of these essential enzymes, we designed and synthesized a series of uridine bisphosphonates (UBPs), wherein the diphosphate bridging oxygen of the UDP and UDP-sugar is replaced by a substituted methylene group (CXY; X/Y = F/F, Cl/Cl, (S)-H/F, (R)-H/F, H/H, CH3/CH3). These compounds, which incorporated as the conjugating sugar an N-acetylglucosamine (GlcNAc) substituent at the β-phosphonate, were evaluated as inhibitors of a representative polytopic PGT (WecA from Thermotoga maritima) and a monotopic PGT (PglC from Campylobacter jejuni). Although CHF-BP most closely mimics pyrophosphate with respect to its acid/base properties, the less basic CF2-BP conjugate most strongly inhibited PglC, whereas the more basic CH2-BP analogue was the strongest inhibitor of WecA. These surprising differences indicate different modes of ligand binding for the different PGT superfamilies implicating a modified P-O- interaction with the structural Mg2+, consistent with their catalytic divergence. Furthermore, at least for the monoPGT superfamily example, this was not the sole determinant of ligand binding: the two diastereomeric CHF-BP conjugates, which feature a chiral center at the Pα-CHF-Pβ carbon, exhibited strikingly different binding affinities and the inclusion of GlcNAc with the native α-anomer configuration significantly improved binding affinity. UBP-sugars are a valuable tool for elucidating the structures and mechanisms of the distinct PGT superfamilies and offer a promising scaffold to develop novel antibiotic agents for the exclusively prokaryotic monoPGT superfamily.
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Affiliation(s)
- Leah M. Seebald
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Pouya Haratipour
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Michaela R. Jacobs
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Hannah M. Bernstein
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Boris A. Kashemirov
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Dodge GJ, Anderson AJ, He Y, Liu W, Viner R, Imperiali B. Mapping the architecture of the initiating phosphoglycosyl transferase from S. enterica O-antigen biosynthesis in a liponanoparticle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.16.545297. [PMID: 37398332 PMCID: PMC10312794 DOI: 10.1101/2023.06.16.545297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Bacterial cell surface glycoconjugates are critical for cell survival and for interactions between bacteria and their hosts. Consequently, the pathways responsible for their biosynthesis have untapped potential as therapeutic targets. The localization of many glycoconjugate biosynthesis enzymes to the membrane represents a significant challenge for expressing, purifying, and characterizing these enzymes. Here, we leverage cutting-edge methods to stabilize, purify, and structurally characterize WbaP, a phosphoglycosyl transferase (PGT) from Salmonella enterica (LT2) O-antigen biosynthesis without detergent solubilization from the lipid bilayer. From a functional perspective, these studies establish WbaP as a homodimer, reveal the structural elements responsible for oligomerization, shed light on the regulatory role of a domain of unknown function embedded within WbaP, and identify conserved structural motifs between PGTs and functionally unrelated UDP-sugar dehydratases. From a technological perspective, the strategy developed here is generalizable and provides a toolkit for studying small membrane proteins embedded in liponanoparticles beyond PGTs.
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Affiliation(s)
- Greg J. Dodge
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alyssa J. Anderson
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yi He
- Thermo Fisher Scientific, San Jose CA 95134, USA
| | - Weijing Liu
- Thermo Fisher Scientific, San Jose CA 95134, USA
| | - Rosa Viner
- Thermo Fisher Scientific, San Jose CA 95134, USA
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Anderson AJ, Dodge GJ, Allen KN, Imperiali B. Co-conserved sequence motifs are predictive of substrate specificity in a family of monotopic phosphoglycosyl transferases. Protein Sci 2023; 32:e4646. [PMID: 37096962 PMCID: PMC10186338 DOI: 10.1002/pro.4646] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/14/2023] [Accepted: 04/18/2023] [Indexed: 04/26/2023]
Abstract
Monotopic phosphoglycosyl transferases (monoPGTs) are an expansive superfamily of enzymes that catalyze the first membrane-committed step in the biosynthesis of bacterial glycoconjugates. MonoPGTs show a strong preference for their cognate nucleotide diphospho-sugar (NDP-sugar) substrates. However, despite extensive characterization of the monoPGT superfamily through previous development of a sequence similarity network comprising >38,000 nonredundant sequences, the connection between monoPGT sequence and NDP-sugar substrate specificity has remained elusive. In this work, we structurally characterize the C-terminus of a prototypic monoPGT for the first time and show that 19 C-terminal residues play a significant structural role in a subset of monoPGTs. This new structural information facilitated the identification of co-conserved sequence "fingerprints" that predict NDP-sugar substrate specificity for this subset of monoPGTs. A Hidden Markov model was generated that correctly assigned the substrate of previously unannotated monoPGTs. Together, these structural, sequence, and biochemical analyses have delivered new insight into the determinants guiding substrate specificity of monoPGTs and have provided a strategy for assigning the NDP-sugar substrate of a subset of enzymes in the superfamily that use UDP-di-N-acetyl bacillosamine. Moving forward, this approach may be applied to identify additional sequence motifs that serve as fingerprints for monoPGTs of differing UDP-sugar substrate specificity.
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Affiliation(s)
- Alyssa J. Anderson
- Department of Biology and Department of ChemistryMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Greg J. Dodge
- Department of Biology and Department of ChemistryMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Karen N. Allen
- Department of ChemistryBoston UniversityBostonMassachusettsUSA
| | - Barbara Imperiali
- Department of Biology and Department of ChemistryMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
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Arbour CA, Nagar R, Bernstein HM, Ghosh S, Al-Sammarraie Y, Dorfmueller HC, Ferguson MAJ, Stanley-Wall NR, Imperiali B. Defining Early Steps in B. subtilis Biofilm Biosynthesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529487. [PMID: 36865097 PMCID: PMC9980142 DOI: 10.1101/2023.02.22.529487] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The Bacillus subtilis extracellular biofilm matrix includes an exopolysaccharide that is critical for the architecture and function of the community. To date, our understanding of the biosynthetic machinery and the molecular composition of the exopolysaccharide of B. subtilis remains unclear and incomplete. This report presents synergistic biochemical and genetic studies built from a foundation of comparative sequence analyses targeted at elucidating the activities of the first two membrane-committed steps in the exopolysaccharide biosynthetic pathway. By taking this approach, we determined the nucleotide sugar donor and lipid-linked acceptor substrates for the first two enzymes in the B. subtilis biofilm exopolysaccharide biosynthetic pathway. EpsL catalyzes the first phosphoglycosyl transferase step using UDP-di- N -acetyl bacillosamine as phospho-sugar donor. EpsD is a GT-B fold glycosyl transferase that facilitates the second step in the pathway that utilizes the product of EpsL as an acceptor substrate and UDP- N -acetyl glucosamine as the sugar donor. Thus, the study defines the first two monosaccharides at the reducing end of the growing exopolysaccharide unit. In doing so we provide the first evidence of the presence of bacillosamine in an exopolysaccharide synthesized by a Gram-positive bacterium. IMPORTANCE Biofilms are the communal way of life that microbes adopt to increase survival. Key to our ability to systematically promote or ablate biofilm formation is a detailed understanding of the biofilm matrix macromolecules. Here we identify the first two essential steps in the Bacillus subtilis biofilm matrix exopolysaccharide synthesis pathway. Together our studies and approaches provide the foundation for the sequential characterization of the steps in exopolysaccharide biosynthesis, using prior steps to enable chemoenzymatic synthesis of the undecaprenol diphosphate-linked glycan substrates.
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Affiliation(s)
- Christine A. Arbour
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA)
| | - Rupa Nagar
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Hannah M. Bernstein
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA)
| | - Soumi Ghosh
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA)
| | - Yusra Al-Sammarraie
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Helge C. Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Michael A. J. Ferguson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Nicola R. Stanley-Wall
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA)
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Anderson AJ, Seebald LM, Arbour CA, Imperiali B. Probing Monotopic Phosphoglycosyl Transferases from Complex Cellular Milieu. ACS Chem Biol 2022; 17:3191-3197. [PMID: 36346917 PMCID: PMC9703085 DOI: 10.1021/acschembio.2c00648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Monotopic phosphoglycosyl transferase enzymes (monoPGTs) initiate the assembly of prokaryotic glycoconjugates essential for bacterial survival and proliferation. MonoPGTs belong to an expansive superfamily with a diverse and richly annotated sequence space; however, the biochemical roles of most monoPGTs in glycoconjugate biosynthesis pathways remain elusive. To better understand these critical enzymes, we have implemented activity-based protein profiling (ABPP) probes as protein-centric, membrane protein compatible tools that lay the groundwork for understanding the activity and regulation of the monoPGT superfamily from a cellular proteome. With straightforward gel-based readouts, we demonstrate robust, covalent labeling at the active site of various representative monoPGTs from cell membrane fractions using 3-phenyl-2H-azirine probes.
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Affiliation(s)
- Alyssa J. Anderson
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Leah M. Seebald
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christine A. Arbour
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Barbara Imperiali
- Department of Biology and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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