1
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Carrica MDC, Gorgojo JP, Alvarez-Hayes J, Valdez HA, Lamberti YA, Rodriguez ME. BPP0974 is a Bordetella parapertussis adhesin expressed in the avirulent phase, implicated in biofilm formation and intracellular survival. Microb Pathog 2024; 193:106754. [PMID: 38897361 DOI: 10.1016/j.micpath.2024.106754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/28/2024] [Accepted: 06/16/2024] [Indexed: 06/21/2024]
Abstract
B: parapertussis is a bacterium that causes whooping cough, a severe respiratory infection disease, that has shown an increased incidence in the population. Upon transmission through aerosol droplets, the initial steps of host colonization critically depend on the bacterial adhesins. We here described BPP0974, a B. parapertussis protein that exhibits the typical domain architecture of the large repetitive RTX adhesin family. BPP0974 was found to be retained in the bacterial membrane and secreted into the culture medium. This protein was found overexpressed in the avirulent phase of B. parapertussis, the phenotype proposed for initial host colonization. Interestingly, BPP0974 was found relevant for the biofilm formation as well as involved in the bacterial attachment to and survival within the respiratory epithelial cells. Taken together, our results suggest a role for BPP0974 in the early host colonization and pathogenesis of B. parapertussis.
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Affiliation(s)
- Mariela Del Carmen Carrica
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina.
| | - Juan Pablo Gorgojo
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Jimena Alvarez-Hayes
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Hugo Alberto Valdez
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Yanina Andrea Lamberti
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Maria Eugenia Rodriguez
- CINDEFI (UNLP, CONICET La Plata), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina.
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2
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Tyagi S, Yadav RK, Krishnan V. Determination of the Crystal Structure of the Cell Wall-Anchored Proteins and Pilins. Methods Mol Biol 2024; 2727:159-191. [PMID: 37815717 DOI: 10.1007/978-1-0716-3491-2_14] [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] [Indexed: 10/11/2023]
Abstract
Surface proteins and pili (or pilus) anchored on the Gram-positive bacterial cell wall play a vital role in adhesion, colonization, biofilm formation, and immunomodulation. The pilus consists of building blocks called pilins or pilus subunits. The surface proteins and pilins share some common sequences and structural features. They contain an N-terminal signal sequence and the C-terminal cell wall sorting region, enabling their transportation across the membrane and covalent attachment to the bacterial cell wall, respectively. The transpeptidase enzymes called sortases facilitate the covalent links between the pilins during the pilus assembly and between surface proteins or basal subunits of pili and peptidoglycan-bridge during the cell wall anchoring. Thus, elucidating three-dimensional structures for the surface proteins and pilins at the atomic level is essential for understanding the mechanism of adhesion, pilus assembly, and host interaction. This chapter aims to provide a general protocol for crystal structure determination of surface proteins and pilins anchored on the Gram-positive bacterial cell wall and substrates for sortases. The protocol involves the production of recombinant protein, crystallization, and structure determination by X-ray crystallography technique.
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Affiliation(s)
- Shivangi Tyagi
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Rajnesh Kumari Yadav
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India
| | - Vengadesan Krishnan
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, India.
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3
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Islam ST, Jolivet NY, Cuzin C, Belgrave AM, My L, Fleuchot B, Faure LM, Mahanta U, Kezzo AA, Saïdi F, Sharma G, Fiche JB, Bratton BP, Herrou J, Nollmann M, Shaevitz JW, Durand E, Mignot T. Unmasking of the von Willebrand A-domain surface adhesin CglB at bacterial focal adhesions mediates myxobacterial gliding motility. SCIENCE ADVANCES 2023; 9:eabq0619. [PMID: 36812310 PMCID: PMC9946355 DOI: 10.1126/sciadv.abq0619] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
The predatory deltaproteobacterium Myxococcus xanthus uses a helically-trafficked motor at bacterial focal-adhesion (bFA) sites to power gliding motility. Using total internal reflection fluorescence and force microscopies, we identify the von Willebrand A domain-containing outer-membrane (OM) lipoprotein CglB as an essential substratum-coupling adhesin of the gliding transducer (Glt) machinery at bFAs. Biochemical and genetic analyses reveal that CglB localizes to the cell surface independently of the Glt apparatus; once there, it is recruited by the OM module of the gliding machinery, a heteroligomeric complex containing the integral OM β barrels GltA, GltB, and GltH, as well as the OM protein GltC and OM lipoprotein GltK. This Glt OM platform mediates the cell-surface accessibility and retention of CglB by the Glt apparatus. Together, these data suggest that the gliding complex promotes regulated surface exposure of CglB at bFAs, thus explaining the manner by which contractile forces exerted by inner-membrane motors are transduced across the cell envelope to the substratum.
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Affiliation(s)
- Salim T. Islam
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Nicolas Y. Jolivet
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Clémence Cuzin
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Akeisha M. Belgrave
- Integrated Sciences Program, Harrisburg University of Science and Technology, Harrisburg, PA 17101, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Laetitia My
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Betty Fleuchot
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Laura M. Faure
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Utkarsha Mahanta
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru-560100, Karnataka, India
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana-502284, India
| | - Ahmad A. Kezzo
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Fares Saïdi
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Gaurav Sharma
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru-560100, Karnataka, India
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana-502284, India
| | - Jean-Bernard Fiche
- Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, 34090 Montpellier, France
| | - Benjamin P. Bratton
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN 37232, USA
| | - Julien Herrou
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Marcelo Nollmann
- Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, 34090 Montpellier, France
| | - Joshua W. Shaevitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Eric Durand
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
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Yadav RK, Krishnan V. New structural insights into the
PI
‐2 pilus from
Streptococcus oralis
, an early dental plaque colonizer. FEBS J 2022; 289:6342-6366. [DOI: 10.1111/febs.16527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/20/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Rajnesh Kumari Yadav
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology NCR Biotech Science Cluster Faridabad India
- School of Biotechnology KIIT University Odisha India
| | - Vengadesan Krishnan
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology NCR Biotech Science Cluster Faridabad India
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5
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van Leeuwen HC, Roelofs D, Corver J, Hensbergen P. Phylogenetic analysis of the bacterial Pro-Pro-endopeptidase domain reveals a diverse family including secreted and membrane anchored proteins. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100024. [PMID: 34841315 PMCID: PMC8610288 DOI: 10.1016/j.crmicr.2021.100024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 11/21/2022] Open
Abstract
Bacterial Pro-Pro-endopeptidase (PPEP) is the latest member of the metalloendopeptidase class (E.C. 3.4.24.89). PPEP homologs are found in two firmicutes orders, clostridiales and bacillales spread over 9 genera and more than 130 species. Some PPEP homologs have acquired additional anchor domains that bind noncovalently to various elements of the bacterial peptidoglycan cell wall. Prototype family members, PPEP-1 and PPEP-2, target bacterial surface adhesion proteins, but homologs could target other extracellular proteins.
Pro-Pro-endopeptidases (PPEP, EC 3.4.24.89) are secreted, zinc metalloproteases that have the unusual capacity to cleave a peptide bond between two prolines, a bond that is generally less sensitive to proteolytic cleavage. Two well studied members of the family are PPEP-1 and PPEP-2, produced by Clostridioides difficile, a human pathogen, and Paenibacillus alvei, a bee secondary invader, respectively. Both proteases seem to be involved in mediating bacterial adhesion by cleaving cell surface anchor proteins on the bacterium itself. By using basic alignment and phylogenetic profiling analysis, this work shows that the complete family of proteins that contain a PPEP domain includes proteins from more than 130 species spread over 9 genera. These analyses also suggest that the PPEP domain spread through horizontal gene transfer events between species within the Firmicutes’ classes Bacilli and Clostridia. Bacterial species containing PPEP homologs are found in diverse habitats, varying from human pathogens and gut microbiota to free-living bacteria, which were isolated from various environments, including extreme conditions such as hot springs, desert soil and salt lakes. The phylogenetic tree reveals the relationships between family members and suggests that smaller subgroups could share cleavage specificity, substrates and functional similarity. Except for PPEP-1 and PPEP-2, no cleavage specificity, specific physiological target, or function has been assigned for any of the other PPEP-family members. Some PPEP proteins have acquired additional domains that recognize and bind noncovalently to various elements of the bacterial peptidoglycan cell-wall, anchoring these PPEPs. Secreted or anchored to the cell-wall surface PPEP proteins seem to perform various functions.
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Affiliation(s)
- Hans C van Leeuwen
- Department of CBRN Protection, Netherlands Organization for Applied Scientific Research TNO, Lange Kleiweg 137, 2288 GJ Rijswijk, the Netherlands
| | - Dick Roelofs
- KeyGene, Agro Business Park 90, 6708 PW Wageningen, the Netherlands
| | - Jeroen Corver
- Department of Medical Microbiology, Leiden University Medical Center, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, the Netherlands
| | - Paul Hensbergen
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Albinusdreef 2, PO Box 9600, 2300 RC Leiden, the Netherlands
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6
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Prajapati A, Palva A, von Ossowski I, Krishnan V. LrpCBA pilus proteins of gut-dwelling Ligilactobacillus ruminis: crystallization and X-ray diffraction analysis. Acta Crystallogr F Struct Biol Commun 2021; 77:238-245. [PMID: 34341189 PMCID: PMC8329715 DOI: 10.1107/s2053230x21007263] [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: 06/15/2021] [Accepted: 07/13/2021] [Indexed: 11/10/2022] Open
Abstract
Adhesion to host surfaces for bacterial survival and colonization involves a variety of molecular mechanisms. Ligilactobacillus ruminis, a strict anaerobe and gut autochthonous (indigenous) commensal, relies on sortase-dependent pili (LrpCBA) for adherence to the intestinal inner walls, thereby withstanding luminal content flow. Here, the LrpCBA pilus is a promiscuous binder to gut collagen, fibronectin and epithelial cells. Structurally, the LrpCBA pilus displays a representative hetero-oligomeric arrangement and consists of three types of pilin subunit, each with its own location and function, i.e. tip LrpC for adhesion, basal LrpB for anchoring and backbone LrpA for length. To provide further structural insights into the assembly, anchoring and functional mechanisms of sortase-dependent pili, each of the L. ruminis pilus proteins was produced recombinantly for crystallization and X-ray diffraction analysis. Crystals of LrpC, LrpB, LrpA and truncated LrpA generated by limited proteolysis were obtained and diffracted to resolutions of 3.0, 1.5, 2.2 and 1.4 Å, respectively. Anomalous data were also collected from crystals of selenomethionine-substituted LrpC and an iodide derivative of truncated LrpA. Successful strategies for protein production, crystallization and derivatization are reported.
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Affiliation(s)
- Amar Prajapati
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121 001, India
| | - Airi Palva
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | | | - Vengadesan Krishnan
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121 001, India
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7
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Exploiting pilus-mediated bacteria-host interactions for health benefits. Mol Aspects Med 2021; 81:100998. [PMID: 34294411 DOI: 10.1016/j.mam.2021.100998] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/30/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023]
Abstract
Surface pili (or fimbriae) are an important but conspicuous adaptation of several genera and species of Gram-negative and Gram-positive bacteria. These long and non-flagellar multi-subunit adhesins mediate the initial contact that a bacterium has with a host or environment, and thus have come to be regarded as a key colonization factor for virulence activity in pathogens or niche adaptation in commensals. Pili in pathogenic bacteria are well recognized for their roles in the adhesion to host cells, colonization of tissues, and establishment of infection. As an 'anti-adhesive' ploy, targeting pilus-mediated attachment for disruption has become a potentially effective alternative to using antibiotics. In this review, we give a description of the several structurally distinct bacterial pilus types thus far characterized, and as well offer details about the intricacy of their individual structure, assembly, and function. With a molecular understanding of pilus biogenesis and pilus-mediated host interactions also provided, we go on to describe some of the emerging new approaches and compounds that have been recently developed to prevent the adhesion, colonization, and infection of piliated bacterial pathogens.
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8
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Clostridium perfringens Produces an Adhesive Pilus Required for the Pathogenesis of Necrotic Enteritis in Poultry. J Bacteriol 2021; 203:JB.00578-20. [PMID: 33468589 PMCID: PMC8088525 DOI: 10.1128/jb.00578-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/07/2021] [Indexed: 12/19/2022] Open
Abstract
Clostridium perfringens type G strains cause necrotic enteritis (NE) in poultry, an economically important disease that is a major target of in-feed antibiotics. NE is a multifactorial disease, involving not only the critically important NetB toxin but also additional virulence and virulence-associated factors. We previously identified a C. perfringens chromosomal locus (VR-10B) associated with disease-causing strains that is predicted to encode a sortase-dependent pilus. In the current study, we sought to provide direct evidence for the production of a pilus by C. perfringens and establish its role in NE pathogenesis. Pilus structures in virulent C. perfringens strain CP1 were visualized by transmission electron microscopy (TEM) of immunogold-labeled cells. Filamentous structures were observed extending from the cell surface in wild-type CP1 but not from isogenic pilin-null mutant strains. In addition, immunoblotting of cell surface proteins demonstrated that CP1, but not the null mutant strains, produced a high molecular weight ladder-like pattern characteristic of a pilus polymer. Binding to collagen types I, II, and IV was significantly reduced (Tukey's test, P < 0.01) in all three pilin mutants compared to CP1 and could be specifically blocked by CnaA and FimA antisera, indicating that these pilins participate in adherence. Furthermore, fimA and fimB null mutants were both severely attenuated in their ability to cause disease in an in vivo chicken NE challenge model. Together, these results provide the first direct evidence for the production of a sortase-dependent pilus by C. perfringens and confirm its critical role in NE pathogenesis and collagen binding.IMPORTANCE In necrotic enteritis (NE), an intestinal disease of chickens, Clostridium perfringens cells adhere tightly to damaged intestinal tissue, but the factors involved are not known. We previously discovered a cluster of C. perfringens genes predicted to encode a pilus, a hair-like bacterial surface structure commonly involved in adherence. In the current study, we have directly imaged this pilus using transmission electron microscopy (TEM). We also show that inactivation of the pilus genes stops pilus production, significantly reducing the bacterium's ability to bind collagen and cause disease. Importantly, this is the first direct evidence for the production of a sortase-dependent pilus by C. perfringens, revealing a promising new target for developing therapeutics to combat this economically important disease.
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9
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Arora S, Gordon J, Hook M. Collagen Binding Proteins of Gram-Positive Pathogens. Front Microbiol 2021; 12:628798. [PMID: 33613497 PMCID: PMC7893114 DOI: 10.3389/fmicb.2021.628798] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Collagens are the primary structural components of mammalian extracellular matrices. In addition, collagens regulate tissue development, regeneration and host defense through interaction with specific cellular receptors. Their unique triple helix structure, which requires a glycine residue every third amino acid, is the defining structural feature of collagens. There are 28 genetically distinct collagens in humans. In addition, several other unrelated human proteins contain a collagen domain. Gram-positive bacteria of the genera Staphylococcus, Streptococcus, Enterococcus, and Bacillus express cell surface proteins that bind to collagen. These proteins of Gram-positive pathogens are modular proteins that can be classified into different structural families. This review will focus on the different structural families of collagen binding proteins of Gram-positive pathogen. We will describe how these proteins interact with the triple helix in collagens and other host proteins containing a collagenous domain and discuss how these interactions can contribute to the pathogenic processes.
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Affiliation(s)
- Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
| | - Jay Gordon
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, United States
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10
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Heidler TV, Ernits K, Ziolkowska A, Claesson R, Persson K. Porphyromonas gingivalis fimbrial protein Mfa5 contains a von Willebrand factor domain and an intramolecular isopeptide. Commun Biol 2021; 4:106. [PMID: 33495563 PMCID: PMC7835359 DOI: 10.1038/s42003-020-01621-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 12/18/2020] [Indexed: 01/30/2023] Open
Abstract
The Gram-negative bacterium Porphyromonas gingivalis is a secondary colonizer of the oral biofilm and is involved in the onset and progression of periodontitis. Its fimbriae, of type-V, are important for attachment to other microorganisms in the biofilm and for adhesion to host cells. The fimbriae are assembled from five proteins encoded by the mfa1 operon, of which Mfa5 is one of the ancillary tip proteins. Here we report the X-ray structure of the N-terminal half of Mfa5, which reveals a von Willebrand factor domain and two IgG-like domains. One of the IgG-like domains is stabilized by an intramolecular isopeptide bond, which is the first such bond observed in a Gram-negative bacterium. These features make Mfa5 structurally more related to streptococcal adhesins than to the other P. gingivalis Mfa proteins. The structure reported here indicates that horizontal gene transfer has occurred among the bacteria within the oral biofilm.
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Affiliation(s)
- Thomas V. Heidler
- grid.12650.300000 0001 1034 3451Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
| | - Karin Ernits
- grid.12650.300000 0001 1034 3451Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
| | - Agnieszka Ziolkowska
- grid.12650.300000 0001 1034 3451Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
| | - Rolf Claesson
- grid.12650.300000 0001 1034 3451Department of Odontology, Umeå University, 90187 Umeå, Sweden
| | - Karina Persson
- grid.12650.300000 0001 1034 3451Department of Chemistry, Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
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11
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Megta AK, Pratap S, Kant A, Palva A, von Ossowski I, Krishnan V. Crystal structure of the atypically adhesive SpaB basal pilus subunit: Mechanistic insights about its incorporation in lactobacillar SpaCBA pili. Curr Res Struct Biol 2020; 2:229-238. [PMID: 34235482 PMCID: PMC8244301 DOI: 10.1016/j.crstbi.2020.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 02/07/2023] Open
Abstract
To successfully colonize a host or environment, certain genera and species of Gram-positive bacteria have evolved to utilize the so-called sortase-dependent pilus, a long multi-subunit and non-flagellar surface adhesin. One example of this is Lactobacillus rhamnosus GG, a gut-adapted probiotic strain that produces SpaCBA pili. These structures are covalent hetero-oligomers built from three types of pilin subunit, each with a specific location and function (i.e., backbone SpaA for length, tip SpaC for adhesion, and basal SpaB for anchoring). Functionally, the SpaCBA pilus exhibits a promiscuous affinity for components on intestinal surfaces (e.g., mucus, collagen, and epithelial cells), which is largely attributed to the SpaC subunit. Then again, the basal SpaB pilin, in addition to acting as the terminal subunit during pilus assembly, displays an out of character mucoadhesive function. To address the structural basis of this unusual dual functionality, we reveal the 2.39 Å resolution crystal structure of SpaB. SpaB consists of one immunoglobulin-like CnaB domain and contains a putative intermolecular isopeptide bond-linking lysine and internal isopeptide bond-asparagine in an FPKN pilin motif within the C-terminal end. Remarkably, we found that a C-terminal stretch of positively charged lysine and arginine residues likely accounts for the atypical mucoadhesiveness of SpaB. Although harboring an autocatalytic triad of residues for a potential internal isopeptide interaction, the SpaB crystal structure lacked the visible electron density for intact bond formation, yet its presence was subsequently confirmed by mass spectral analysis. Finally, we propose a structural model that captures the exclusive basal positioning of SpaB in the SpaCBA pilus.
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Key Words
- ABC, ammonium bicarbonate
- ACN, acetonitrile
- Cell-wall anchoring
- Cna, collagen adhesin
- ECM, extracellular matrix
- Ig, immunoglobulin
- Lactobacillus rhamnosus GG
- MD, molecular dynamics
- MS, mass spectrometry
- Mucus adhesion
- PDB, Protein Data Bank
- PEG, polyethylene glycol
- Probiotic
- Sortase-dependent SpaCBA pili
- SpaB basal pilin
- rmsd, root mean square deviation
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Affiliation(s)
- Abhin Kumar Megta
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India.,School of Biotechnology, KIIT University, Odisha, 751024, India
| | - Shivendra Pratap
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
| | - Abhiruchi Kant
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India.,Department of Biotechnology, Manipal University, Karnataka, 576104, India
| | - Airi Palva
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, FIN-00014, Finland
| | - Ingemar von Ossowski
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, FIN-00014, Finland
| | - Vengadesan Krishnan
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India
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12
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Kant A, Palva A, von Ossowski I, Krishnan V. Crystal structure of lactobacillar SpaC reveals an atypical five-domain pilus tip adhesin: Exposing its substrate-binding and assembly in SpaCBA pili. J Struct Biol 2020; 211:107571. [PMID: 32653644 DOI: 10.1016/j.jsb.2020.107571] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/23/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022]
Abstract
Adhesion to cell surfaces is an essential and early prerequisite for successful host colonization by bacteria, and in most instances involves the specificities of various adhesins. Among bacterial Gram-positives, some genera and species mediate attachment to host cells by using long non-flagellar appendages called sortase-dependent pili. A case in point is the beneficial Lactobacillus rhamnosus GG gut-adapted strain that produces the so-called SpaCBA pilus, a structure noted for its promiscuous binding to intestinal mucus and collagen. Structurally, SpaCBA pili are heteropolymers of three different pilin-protein subunits, each with its own location and function in the pilus: backbone SpaA for length, basal SpaB for anchoring, and tip SpaC for adhesion. Previously, we solved the SpaA tertiary structure by X-ray crystallography and also reported on the crystallization of SpaB and SpaC. Here, we reveal the full-length high-resolution (1.9 Å) crystal structure of SpaC, a first for a sortase-dependent pilus-bearing commensal. The SpaC structure, unlike the representative four-domain architecture of other Gram-positive tip pilins, espouses an atypically longer five-domain arrangement that includes N-terminal 'binding' and C-terminal 'stalk' regions of two and three domains, respectively. With the prospect of establishing new mechanistic insights, we provide a structural basis for the multi-substrate binding nature of SpaC, as well as a structural model that reconciles its exclusive localization at the SpaCBA pilus tip.
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Affiliation(s)
- Abhiruchi Kant
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 122016, India; Department of Biotechnology, Manipal University, Karnataka 576104, India
| | - Airi Palva
- Department of Veterinary Biosciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Ingemar von Ossowski
- Department of Veterinary Biosciences, University of Helsinki, Helsinki FIN-00014, Finland
| | - Vengadesan Krishnan
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 122016, India.
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13
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Kumari Yadav R, Krishnan V. The adhesive PitA pilus protein from the early dental plaque colonizer Streptococcus oralis: expression, purification, crystallization and X-ray diffraction analysis. Acta Crystallogr F Struct Biol Commun 2020; 76:8-13. [PMID: 31929180 PMCID: PMC6957113 DOI: 10.1107/s2053230x1901642x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 12/05/2019] [Indexed: 11/10/2022] Open
Abstract
PitA is the putative tip adhesin of the pilus islet 2 (PI-2)-encoded sortase-dependent pilus in the Gram-positive Streptococcus oralis, an opportunistic pathogen that often flourishes within the diseased human oral cavity. Early colonization by S. oralis and its interaction with Actinomyces oris seeds the development of oral biofilm or dental plaque. Here, the PI-2 pilus plays a vital role in mediating adherence to host surfaces and other bacteria. A recombinant form of the PitA adhesin has now been produced and crystallized. Owing to the large size (∼100 kDa), flexibility and complicated folding of PitA, obtaining diffraction-quality crystals has been a challenge. However, by the use of limited proteolysis with α-chymotrypsin, the diffraction quality of the PitA crystals was considerably enhanced to 2.16 Å resolution. These crystals belonged to space group P1, with unit-cell parameters a = 61.48, b = 70.87, c = 82.46 Å, α = 80.08, β = 87.02, γ = 87.70°. The anomalous signal from the terbium derivative of α-chymotrypsin-treated PitA crystals prepared with terbium crystallophore (Tb-Xo4) was sufficient to obtain an interpretable electron-density map via terbium SAD phasing.
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Affiliation(s)
- Rajnesh Kumari Yadav
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121 001, India
- School of Biotechnology, KIIT University, Odisha 751 024, India
| | - Vengadesan Krishnan
- Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121 001, India
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14
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Guo S, Vance TD, Stevens CA, Voets I, Davies PL. RTX Adhesins are Key Bacterial Surface Megaproteins in the Formation of Biofilms. Trends Microbiol 2019; 27:453-467. [DOI: 10.1016/j.tim.2018.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/13/2018] [Accepted: 12/12/2018] [Indexed: 12/20/2022]
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15
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Megta AK, Mishra AK, Palva A, von Ossowski I, Krishnan V. Crystal structure of basal pilin SpaE reveals the molecular basis of its incorporation in the lactobacillar SpaFED pilus. J Struct Biol 2019; 207:74-84. [PMID: 31026587 DOI: 10.1016/j.jsb.2019.04.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/15/2019] [Accepted: 04/23/2019] [Indexed: 11/16/2022]
Abstract
For some Gram-positive genera and species, the long-extended and adhesive sortase-dependent pilus plays an essential role during host colonization, biofilm formation, and immune modulation. Lactobacillus rhamnosus GG is a gut-adapted commensal strain that harbors the operonic genes for the SpaCBA and SpaFED pili, both being comprised of three different protein subunits termed the backbone, tip, and basal pilins. Crystal structures of the backbone pilins (SpaA and SpaD) have recently been solved, and here we describe the high-resolution (1.5 Å) structural determination of the SpaE basal pilin. SpaE consists of two immunoglobulin-like CnaB domains, with each displaying a spontaneously formed internal isopeptide bond, though apparently slow forming in the N-terminal domain. Remarkably, SpaE contains an atypically lengthy unstructured C-terminal tail, along with an YPKN pilin motif peptide, which is normally reserved for backbone subunits. Based on our analysis of the crystal structure data, we provide a molecular model for the basal positioning of the SpaE pilin within the SpaFED pilus.
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Affiliation(s)
- Abhin Kumar Megta
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana 121 001, India; School of Biotechnology, KIIT University, Odisha 751024, India
| | - Arjun K Mishra
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana 121 001, India
| | - Airi Palva
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | | | - Vengadesan Krishnan
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, Haryana 121 001, India.
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16
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Alfaro-Saldaña E, Hernández-Sánchez A, Patrón-Soberano OA, Astello-García M, Méndez-Cabañas JA, García-Meza JV. Sequence analysis and confirmation of the type IV pili-associated proteins PilY1, PilW and PilV in Acidithiobacillus thiooxidans. PLoS One 2019; 14:e0199854. [PMID: 30615628 PMCID: PMC6322766 DOI: 10.1371/journal.pone.0199854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 11/24/2018] [Indexed: 11/19/2022] Open
Abstract
Acidithiobacillus thiooxidans is an acidophilic chemolithoautotrophic bacterium widely used in the mining industry due to its metabolic sulfur-oxidizing capability. The biooxidation of sulfide minerals is enhanced through the attachment of At. thiooxidans cells to the mineral surface. The Type IV pili (TfP) of At. thiooxidans may play an important role in the bacteria attachment since TfP play a key adhesive role in the attachment and colonization of different surfaces. In this work, we report for the first time the mRNA sequence of three TfP proteins from At. thiooxidans, the adhesin protein PilY1 and the TfP pilins PilW and PilV. The nucleotide sequences of these TfP proteins show changes in some nucleotide positions with respect to the corresponding annotated sequences. The bioinformatic analyses and 3D-modeling of protein structures sustain their classification as TfP proteins, as structural homologs of the corresponding proteins of Ps. aeruginosa, results that sustain the role of PilY1, PilW and PilV in pili assembly. Also, that PilY1 comprises the conserved Neisseria-PilC (superfamily) domain of the tip-associated adhesin, while PilW of the superfamily of putative TfP assembly proteins and PilV belongs to the superfamily of TfP assembly protein. In addition, the analyses suggested the presence of specific functional domains involved in adhesion, energy transduction and signaling functions. The phylogenetic analysis indicated that the PilY1 of Acidithiobacillus genus forms a cohesive group linked with iron- and/or sulfur-oxidizing microorganisms from acid mine drainage or mine tailings.
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Affiliation(s)
- Elvia Alfaro-Saldaña
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
- Biofísica Molecular, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - Araceli Hernández-Sánchez
- Biofísica Molecular, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - O. Araceli Patrón-Soberano
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, San Luis Potosí, México
| | - Marizel Astello-García
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - J. Alfredo Méndez-Cabañas
- Biofísica Molecular, Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - J. Viridiana García-Meza
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
- * E-mail:
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17
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Abstract
To interact with the external environments, bacteria often display long proteinaceous appendages on their cell surface, called pili or fimbriae. These non-flagellar thread-like structures are polymers composed of covalently or non-covalently interacting repeated pilin subunits. Distinct pilus classes can be identified on basis of their assembly pathways, including chaperone-usher pili, type V pili, type IV pili, curli and fap fibers, conjugative and type IV secretion pili, as well as sortase-mediated pili. Pili play versatile roles in bacterial physiology, and can be involved in adhesion and host cell invasion, DNA and protein secretion and uptake, biofilm formation, cell motility and more. Recent advances in structure determination of components involved in the various pilus systems has enabled a better molecular understanding of their mechanisms of assembly and function. In this chapter we describe the diversity in structure, biogenesis and function of the different pilus systems found in Gram-positive and Gram-negative bacteria, and review their potential as anti-microbial targets.
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Affiliation(s)
- Magdalena Lukaszczyk
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050, Brussels, Belgium
| | - Brajabandhu Pradhan
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050, Brussels, Belgium
| | - Han Remaut
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
- Structural and Molecular Microbiology, Structural Biology Research Center, VIB, Pleinlaan 2, 1050, Brussels, Belgium.
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18
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Identification of potential inhibitors of sortase A: Binding studies, in-silico docking and protein-protein interaction studies of sortase A from Enterococcus faecalis. Int J Biol Macromol 2018; 120:1906-1916. [PMID: 30268755 DOI: 10.1016/j.ijbiomac.2018.09.174] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 09/23/2018] [Accepted: 09/26/2018] [Indexed: 12/16/2022]
Abstract
Enterococcus faecalis (Ef) is a Gram positive multidrug resistant (MDR) bacterium contributing about 70% of total enterococcal infections. In Ef, a membrane anchored transpeptidase Sortase A plays a major role in biofilm formation. Therefore, it has been recognized as an ideal drug target against Ef. In this regard to identify the potential inhibitors of Ef Sortase A (EfSrtA∆59), we have cloned, expressed and purified EfSrtA∆59. We have also done the in-silico docking studies to identify lead molecules interacting with EfSrtA∆59. Furthermore, the binding studies of these identified lead molecules were performed with EfSrtA∆59 using fluorescence and CD spectroscopic studies. We also identified the interaction partner of EfSrtA∆59 using STRING. Protein-protein docking studies were also performed. Docking experiment revealed that benzylpenicillin, cefotaxime, pantoprazole and valsartan were bound to same site on the protein with similar interactions. Binding studies using fluorescence spectroscopic studies confirmed the binding of all the ligands to EfSrtA∆59, which was further validated by far and near-UV CD experiments. Thermo stability experiments validate the stability-activity trade-off hypothesis. Sequence based interaction studies identified that EfSrtA∆59 interact with the Ef_1091, Ef_1093 and Ef_2658 proteins. Homology model of Ef_1091 and Ef_1093 was docked with modeled EfSrtA∆59 and their interactions are also discussed.
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19
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Song JY, Lim JH, Lim S, Yong Z, Seo HS. Progress toward a group B streptococcal vaccine. Hum Vaccin Immunother 2018; 14:2669-2681. [PMID: 29995578 PMCID: PMC6314413 DOI: 10.1080/21645515.2018.1493326] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/18/2018] [Accepted: 06/19/2018] [Indexed: 01/31/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of severe invasive disease in neonate, elderly, and immunocompromised patients worldwide. Despite recent advances in the diagnosis and intrapartum antibiotic prophylaxis (IAP) of GBS infections, it remains one of the most common causes of neonatal morbidity and mortality, causing serious infections. Furthermore, recent studies reported an increasing number of GBS infections in pregnant women and elderly. Although IAP is effective, it has several limitations, including increasing antimicrobial resistance and late GBS infection after negative antenatal screening. Maternal immunization is the most promising and effective countermeasure against GBS infection in neonates. However, no vaccine is available to date, but two types of vaccines, protein subunit and capsular polysaccharide conjugate vaccines, were investigated in clinical trials. Here, we provide an overview of the GBS vaccine development status and recent advances in the development of immunoassays to evaluate the GBS vaccine clinical efficacy.
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Affiliation(s)
- Joon Young Song
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae Hyang Lim
- Department of Microbiology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Sangyong Lim
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Zhi Yong
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Ho Seong Seo
- Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Biotechnology and Applied Radioisotope Science, University of Science and Technology, Daejeon, Republic of Korea
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20
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Klychnikov OI, Shamorkina TM, Weeks SD, van Leeuwen HC, Corver J, Drijfhout JW, van Veelen PA, Sluchanko NN, Strelkov SV, Hensbergen PJ. Discovery of a new Pro-Pro endopeptidase, PPEP-2, provides mechanistic insights into the differences in substrate specificity within the PPEP family. J Biol Chem 2018; 293:11154-11165. [PMID: 29794027 DOI: 10.1074/jbc.ra118.003244] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/22/2018] [Indexed: 12/20/2022] Open
Abstract
Pro-Pro endopeptidases (PPEPs) belong to a recently discovered family of proteases capable of hydrolyzing a Pro-Pro bond. The first member from the bacterial pathogen Clostridium difficile (PPEP-1) cleaves two C. difficile cell-surface proteins involved in adhesion, one of which is encoded by the gene adjacent to the ppep-1 gene. However, related PPEPs may exist in other bacteria and may shed light on substrate specificity in this enzyme family. Here, we report on the homolog of PPEP-1 in Paenibacillus alvei, which we denoted PPEP-2. We found that PPEP-2 is a secreted metalloprotease, which likewise cleaved a cell-surface protein encoded by an adjacent gene. However, the cleavage motif of PPEP-2, PLP↓PVP, is distinct from that of PPEP-1 (VNP↓PVP). As a result, an optimal substrate peptide for PPEP-2 was not cleaved by PPEP-1 and vice versa. To gain insight into the specificity mechanism of PPEP-2, we determined its crystal structure at 1.75 Å resolution and further confirmed the structure in solution using small-angle X-ray scattering (SAXS). We show that a four-amino-acid loop, which is distinct in PPEP-1 and -2 (GGST in PPEP-1 and SERV in PPEP-2), plays a crucial role in substrate specificity. A PPEP-2 variant, in which the four loop residues had been swapped for those from PPEP-1, displayed a shift in substrate specificity toward PPEP-1 substrates. Our results provide detailed insights into the PPEP-2 structure and the structural determinants of substrate specificity in this new family of PPEP proteases.
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Affiliation(s)
- Oleg I Klychnikov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | - Stephen D Weeks
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | | | | | - Jan W Drijfhout
- Immunohematology and Blood Transfusion, Leiden University Medical Center, 2300 Leiden, The Netherlands
| | | | - Nikolai N Sluchanko
- the A. N. Bach Institute of Biochemistry, Federal Research Center of Biotechnology of the Russian Academy of Sciences, 119071 Moscow, Russia, and.,the Department of Biophysics, Faculty of Biology, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sergei V Strelkov
- From the Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
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21
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Becke TD, Ness S, Gürster R, Schilling AF, di Guilmi AM, Sudhop S, Hilleringmann M, Clausen-Schaumann H. Single Molecule Force Spectroscopy Reveals Two-Domain Binding Mode of Pilus-1 Tip Protein RrgA of Streptococcus pneumoniae to Fibronectin. ACS NANO 2018; 12:549-558. [PMID: 29298375 DOI: 10.1021/acsnano.7b07247] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
For host cell adhesion and invasion, surface piliation procures benefits for bacteria. A detailed investigation of how pili adhere to host cells is therefore a key aspect in understanding their role during infection. Streptococcus pneumoniae TIGR 4, a clinical relevant serotype 4 strain, is capable of expressing pilus-1 with terminal RrgA, an adhesin interacting with host extracellular matrix (ECM) proteins. We used single molecule force spectroscopy to investigate the binding of full-length RrgA and single RrgA domains to fibronectin. Our results show that full-length RrgA and its terminal domains D3 and D4 bind to fibronectin with forces of 51.6 (full length), 52.8 (D3), and 46.2 pN (D4) at force-loading rates of around 1500 pN/s. Selective saturation of D3 and D4 binding sites on fibronectin showed that both domains can interact simultaneously with fibronectin, revealing a two-domain binding mechanism for the pilus-1 tip protein. The high off rates and the corresponding short lifetime of the RrgA Fn bond (τ = 0.26 s) may enable piliated pneumococci to form and maintain a transient contact to fibronectin-containing host surfaces and thus to efficiently scan the surface for specific receptors promoting host cell adhesion and invasion. These molecular properties could be essential for S. pneumoniae pili to mediate initial contact to the host cells and-shared with other piliated Gram-positive bacteria-favor host invasion.
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Affiliation(s)
- Tanja D Becke
- Department for Plastic Surgery and Hand Surgery, Klinikum Rechts der Isar, Technische Universität München , 81675 Munich, Germany
- Center for NanoScience, Ludwig-Maximilians-Universität München , 80799 Munich, Germany
| | | | | | - Arndt F Schilling
- Department for Plastic Surgery and Hand Surgery, Klinikum Rechts der Isar, Technische Universität München , 81675 Munich, Germany
- Klinik für Unfallchirurgie, Orthopädie und Plastische Chirurgie, University Medical Center Göttingen , 37075 Göttingen, Germany
| | | | - Stefanie Sudhop
- Center for NanoScience, Ludwig-Maximilians-Universität München , 80799 Munich, Germany
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22
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von Ossowski I. Novel Molecular Insights about Lactobacillar Sortase-Dependent Piliation. Int J Mol Sci 2017; 18:ijms18071551. [PMID: 28718795 PMCID: PMC5536039 DOI: 10.3390/ijms18071551] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/11/2017] [Accepted: 07/14/2017] [Indexed: 01/09/2023] Open
Abstract
One of the more conspicuous structural features that punctuate the outer cell surface of certain bacterial Gram-positive genera and species is the sortase-dependent pilus. As these adhesive and variable-length protrusions jut outward from the cell, they provide a physically expedient and useful means for the initial contact between a bacterium and its ecological milieu. The sortase-dependent pilus displays an elongated macromolecular architecture consisting of two to three types of monomeric protein subunits (pilins), each with their own specific function and location, and that are joined together covalently by the transpeptidyl activity of a pilus-specific C-type sortase enzyme. Sortase-dependent pili were first detected among the Gram-positive pathogens and subsequently categorized as an essential virulence factor for host colonization and tissue invasion by these harmful bacteria. However, the sortase-dependent pilus was rebranded as also a niche-adaptation factor after it was revealed that “friendly” Gram-positive commensals exhibit the same kind of pilus structures, which includes two contrasting gut-adapted species from the Lactobacillus genus, allochthonous Lactobacillus rhamnosus and autochthonous Lactobacillus ruminis. This review will highlight and discuss what has been learned from the latest research carried out and published on these lactobacillar pilus types.
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Affiliation(s)
- Ingemar von Ossowski
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki FIN-00014, Finland.
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23
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Khare B, V L Narayana S. Pilus biogenesis of Gram-positive bacteria: Roles of sortases and implications for assembly. Protein Sci 2017; 26:1458-1473. [PMID: 28493331 DOI: 10.1002/pro.3191] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/28/2017] [Accepted: 05/03/2017] [Indexed: 12/26/2022]
Abstract
Successful adherence, colonization, and survival of Gram-positive bacteria require surface proteins, and multiprotein assemblies called pili. These surface appendages are attractive pharmacotherapeutic targets and understanding their assembly mechanisms is essential for identifying a new class of 'anti-infectives' that do not elicit microbial resistance. Molecular details of the Gram-negative pilus assembly are available indepth, but the Gram-positive pilus biogenesis is still an emerging field and investigations continue to reveal novel insights into this process. Pilus biogenesis in Gram-positive bacteria is a biphasic process that requires enzymes called pilus-sortases for assembly and a housekeeping sortase for covalent attachment of the assembled pilus to the peptidoglycan cell wall. Emerging structural and functional data indicate that there are at least two groups of Gram-positive pili, which require either the Class C sortase or Class B sortase in conjunction with LepA/SipA protein for major pilin polymerization. This observation suggests two distinct modes of sortase-mediated pilus biogenesis in Gram-positive bacteria. Here we review the structural and functional biology of the pilus-sortases from select streptococcal pilus systems and their role in Gram-positive pilus assembly.
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Affiliation(s)
- Baldeep Khare
- Center for Structural Biology, School of Optometry, University of Alabama at Birmingham, Birmingham, USA
| | - Sthanam V L Narayana
- Center for Structural Biology, School of Optometry, University of Alabama at Birmingham, Birmingham, USA
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24
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Tsai JYC, Loh JMS, Clow F, Lorenz N, Proft T. The Group A Streptococcus serotype M2 pilus plays a role in host cell adhesion and immune evasion. Mol Microbiol 2016; 103:282-298. [PMID: 27741558 DOI: 10.1111/mmi.13556] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2016] [Indexed: 01/22/2023]
Abstract
Group A Streptococcus (GAS), or Streptococcus pyogenes, is a human pathogen that causes diseases ranging from skin and soft tissue infections to severe invasive diseases, such as toxic shock syndrome. Each GAS strain carries a particular pilus type encoded in the variable fibronectin-binding, collagen-binding, T antigen (FCT) genomic region. Here, we describe the functional analysis of the serotype M2 pilus encoded in the FCT-6 region. We found that, in contrast to other investigated GAS pili, the ancillary pilin 1 lacks adhesive properties. Instead, the backbone pilin is important for host cell adhesion and binds several host factors, including fibronectin and fibrinogen. Using a panel of recombinant pilus proteins, GAS gene deletion mutants and Lactococcus lactis gain-of-function mutants we show that, unlike other GAS pili, the FCT-6 pilus also contributes to immune evasion. This was demonstrated by a delay in blood clotting, increased intracellular survival of the bacteria in macrophages, higher bacterial survival rates in human whole blood and greater virulence in a Galleria mellonella infection model in the presence of fully assembled FCT-6 pili.
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Affiliation(s)
- Jia-Yun C Tsai
- Department of Molecular Medicine & Pathology, School of Medical Sciences.,Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand
| | - Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences.,Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand
| | - Fiona Clow
- Department of Molecular Medicine & Pathology, School of Medical Sciences
| | - Natalie Lorenz
- Department of Molecular Medicine & Pathology, School of Medical Sciences
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences.,Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand
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Mongiardini EJ, Parisi GD, Quelas JI, Lodeiro AR. The tight-adhesion proteins TadGEF of Bradyrhizobium diazoefficiens USDA 110 are involved in cell adhesion and infectivity on soybean roots. Microbiol Res 2016; 182:80-8. [PMID: 26686616 DOI: 10.1016/j.micres.2015.10.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/06/2015] [Accepted: 10/10/2015] [Indexed: 01/23/2023]
Abstract
Adhesion of symbiotic bacteria to host plants is an essential early step of the infection process that leads to the beneficial interaction. In the Bradyrhizobium diazoefficiens-soybean symbiosis few molecular determinants of adhesion are known. Here we identified the tight-adhesion gene products TadGEF in the open-reading frames blr3941-blr3943 of the B. diazoefficiens USDA 110 complete genomic sequence. Predicted structure of TadG indicates a transmembrane domain and two extracytosolic domains, from which the C-terminal has an integrin fold. TadE and TadF are also predicted as bearing transmembrane segments. Mutants in tadG or the small cluster tadGEF were impaired in adhesion to soybean roots, and the root infection was delayed. However, nodule histology was not compromised by the mutations, indicating that these effects were restricted to the earliest contact of the B. diazoefficiens and root surfaces. Knowledge of preinfection determinants is important for development of inoculants that are applied to soybean crops worldwide.
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Affiliation(s)
- Elías J Mongiardini
- Laboratorio de Interacciones entre Rizobios y Soja (LIRyS), IBBM-Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT La Plata-CONICET, Calles 47 y 115, B1900AJL La Plata, Argentina
| | - Gustavo D Parisi
- Unidad de Bioinformática Estructural, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, B1876BXD Bernal, Argentina
| | - Juan I Quelas
- Laboratorio de Interacciones entre Rizobios y Soja (LIRyS), IBBM-Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT La Plata-CONICET, Calles 47 y 115, B1900AJL La Plata, Argentina
| | - Aníbal R Lodeiro
- Laboratorio de Interacciones entre Rizobios y Soja (LIRyS), IBBM-Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT La Plata-CONICET, Calles 47 y 115, B1900AJL La Plata, Argentina.
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Krishnan V. Pilins in gram-positive bacteria: A structural perspective. IUBMB Life 2015; 67:533-43. [PMID: 26178080 DOI: 10.1002/iub.1400] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 06/17/2015] [Indexed: 11/11/2022]
Abstract
Pilins or fimbrilins are a class of proteins found in bacterial surface pilus, a hair-like surface appendage. Both the Gram-negative and -positive bacteria produce pilins to assemble pili on their cell-surface for different purposes including adherence, twitching motility, conjugation, immunomodulation, biofilm formation, and electron transfer. Immunogenic properties of the pilins make them attractive vaccine candidates. The polymerized pilins play a key role in the initiation of host adhesion, which is a critical step for bacterial colonization and infection. Because of their key role in adhesion and exposure on the cell surface, targeting the pilins-mediated adhesion (anti-adhesion therapy) is also seen as a promising alternative approach for preventing and treating bacterial infections, one that may overcome their ever-increasing repertoires of resistance mechanisms. Individual pilins interact with each other non-covalently to assemble the pilus fiber with the help of associated proteins like chaperones and Usher in Gram-negative bacteria. In contrast, the pilins in Gram-positive bacteria often connect with each other covalently, with the help of sortases. Certain unique structural features present on the pilins distinguish them from one another across different bacterial strains, and these dictate their cellular targets and functions. While the structure of pilins has been extensively studied in Gram-negative pathogenic bacteria, the pilins in Gram-positive pathogenic bacteria have been in only during the last decade. Recently, the discovery of pilins in non-pathogenic bacteria, such as Lactobacillus rhamnosus GG, has received great attention, though traditionally the attention was on pathogenic bacteria. This review summarizes and discusses the current structural knowledge of pilins in Gram-positive bacteria with emphasis on those pilins which are sortase substrates.
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Affiliation(s)
- Vengadesan Krishnan
- Regional Centre for Biotechnology, NCR-Biotech Science Cluster, Faridabad-121 001, Haryana, India
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Cozzi R, Malito E, Lazzarin M, Nuccitelli A, Castagnetti A, Bottomley MJ, Margarit I, Maione D, Rinaudo CD. Structure and assembly of group B streptococcus pilus 2b backbone protein. PLoS One 2015; 10:e0125875. [PMID: 25942637 PMCID: PMC4420484 DOI: 10.1371/journal.pone.0125875] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/26/2015] [Indexed: 12/03/2022] Open
Abstract
Group B Streptococcus (GBS) is a major cause of invasive disease in infants. Like other Gram-positive bacteria, GBS uses a sortase C-catalyzed transpeptidation mechanism to generate cell surface pili from backbone and ancillary pilin precursor substrates. The three pilus types identified in GBS contain structural subunits that are highly immunogenic and are promising candidates for the development of a broadly-protective vaccine. Here we report the X-ray crystal structure of the backbone protein of pilus 2b (BP-2b) at 1.06Å resolution. The structure reveals a classical IgG-like fold typical of the pilin subunits of other Gram-positive bacteria. The crystallized portion of the protein (residues 185-468) encompasses domains D2 and D3 that together confer high stability to the protein due to the presence of an internal isopeptide bond within each domain. The D2+D3 region, lacking the N-terminal D1 domain, was as potent as the entire protein in conferring protection against GBS challenge in a well-established mouse model. By site-directed mutagenesis and complementation studies in GBS knock-out strains we identified the residues and motives essential for assembly of the BP-2b monomers into high-molecular weight complexes, thus providing new insights into pilus 2b polymerization.
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Abstract
Pili of Gram-positive bacteria are unique structures on the bacterial surface, assembled from covalently linked polypeptide subunits. Pilus assembly proceeds by transpeptidation reactions catalyzed by sortases, followed by covalent anchoring of the filament in the peptidoglycan layer. Another distinctive property is the presence of intramolecular isopeptide bonds, conferring extraordinary chemical and mechanical stability to these elongated structures. Besides their function in cell adhesion and biofilm formation, this section discusses possible application of pilus constituents as vaccine components against Gram-positive pathogens.
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Identification of a group B streptococcal fibronectin binding protein, SfbA, that contributes to invasion of brain endothelium and development of meningitis. Infect Immun 2014; 82:2276-86. [PMID: 24643538 DOI: 10.1128/iai.01559-13] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Group B Streptococcus (GBS) is currently the leading cause of neonatal meningitis. This is due to its ability to survive and multiply in the bloodstream and interact with specialized human brain microvascular endothelial cells (hBMEC), which constitute the blood-brain barrier (BBB). The exact mechanism(s) of GBS-BBB penetration is still largely unknown. We and others have shown that GBS interacts with components of the extracellular matrix. In this study, we demonstrate that GBS of representative serotypes binds immobilized and cell surface fibronectin and identify a putative fibronectin binding protein, streptococcal fibronectin binding protein A (SfbA). Allelic replacement of sfbA in the GBS chromosome resulted in a significant decrease in ability to bind fibronection and invade hBMEC compared with the wild-type (WT) parental strain. Expression of SfbA in the noninvasive strain Lactococcus lactis was sufficient to promote fibronectin binding and hBMEC invasion. Furthermore, the addition of an antifibronectin antibody or an RGD peptide that blocks fibronectin binding to integrins significantly reduced invasion of the WT but not the sfbA-deficient mutant strain, demonstrating the importance of an SfbA-fibronectin-integrin interaction for GBS cellular invasion. Using a murine model of GBS meningitis, we also observed that WT GBS penetrated the brain and established meningitis more frequently than did the ΔsfbA mutant strain. Our data suggest that GBS SfbA plays an important role in bacterial interaction with BBB endothelium and the pathogenesis of streptococcal meningitis.
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Linke-Winnebeck C, Paterson NG, Young PG, Middleditch MJ, Greenwood DR, Witte G, Baker EN. Structural model for covalent adhesion of the Streptococcus pyogenes pilus through a thioester bond. J Biol Chem 2014; 289:177-89. [PMID: 24220033 PMCID: PMC3879542 DOI: 10.1074/jbc.m113.523761] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 11/11/2013] [Indexed: 11/06/2022] Open
Abstract
The human pathogen Streptococcus pyogenes produces pili that are essential for adhesion to host surface receptors. Cpa, the adhesin at the pilus tip, was recently shown to have a thioester-containing domain. The thioester bond is believed to be important in adhesion, implying a mechanism of covalent attachment analogous to that used by human complement factors. Here, we have characterized a second active thioester-containing domain on Cpa, the N-terminal domain of Cpa (CpaN). Expression of CpaN in Escherichia coli gave covalently linked dimers. These were shown by x-ray crystallography and mass spectrometry to comprise two CpaN molecules cross-linked by the polyamine spermidine following reaction with the thioester bonds. This cross-linked CpaN dimer provides a model for the covalent attachment of Cpa to target receptors and thus the streptococcal pilus to host cells. Similar thioester domains were identified in cell wall proteins of other Gram-positive pathogens, suggesting that thioester domains are more widely used and provide a mechanism of adhesion by covalent bonding to target molecules on host cells that mimics that used by the human complement system to eliminate pathogens.
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MESH Headings
- Adhesins, Bacterial/chemistry
- Adhesins, Bacterial/genetics
- Adhesins, Bacterial/metabolism
- Base Sequence
- Complement System Proteins/chemistry
- Complement System Proteins/genetics
- Complement System Proteins/metabolism
- Crystallography, X-Ray
- Escherichia coli
- Fimbriae, Bacterial/chemistry
- Fimbriae, Bacterial/genetics
- Fimbriae, Bacterial/metabolism
- Humans
- Models, Molecular
- Molecular Sequence Data
- Protein Multimerization
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Streptococcus pyogenes/chemistry
- Streptococcus pyogenes/genetics
- Streptococcus pyogenes/pathogenicity
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Affiliation(s)
- Christian Linke-Winnebeck
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
| | - Neil G. Paterson
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
| | - Paul G. Young
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
| | - Martin J. Middleditch
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
| | - David R. Greenwood
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
| | - Gregor Witte
- Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, 81377 Munich, Germany
| | - Edward N. Baker
- From the School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Private Bag 921019, Auckland 1142, New Zealand and
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