1
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Takebe K, Suzuki M, Sangawa T, Kreikemeyer B, Yamaguchi M, Uzawa N, Sumitomo T, Kawabata S, Nakata M. Analysis of FctB3 crystal structure and insight into its structural stabilization and pilin linkage mechanisms. Arch Microbiol 2023; 206:4. [PMID: 37994962 DOI: 10.1007/s00203-023-03727-1] [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: 08/04/2023] [Revised: 10/23/2023] [Accepted: 10/29/2023] [Indexed: 11/24/2023]
Abstract
Streptococcus pyogenes harboring an FCT type 3 genomic region display pili composed of three types of pilins. In this study, the structure of the base pilin FctB from a serotype M3 strain (FctB3) was determined at 2.8 Å resolution. In accordance with the previously reported structure of FctB from a serotype T9 strain (FctB9), FctB3 was found to consist of an immunoglobulin-like domain and proline-rich tail region. Data obtained from structure comparison revealed main differences in the omega (Ω) loop structure and the proline-rich tail direction. In the Ω loop structure, a differential hydrogen bond network was observed, while the lysine residue responsible for linkage to growing pili was located at the same position in both structures, which indicated that switching of the hydrogen bond network in the Ω loop without changing the lysine position is advantageous for linkage to the backbone pilin FctA. The difference in direction of the proline-rich tail is potentially caused by a single residue located at the root of the proline-rich tail. Also, the FctB3 structure was found to be stabilized by intramolecular large hydrophobic interactions instead of an isopeptide bond. Comparisons of the FctB3 and FctA structures indicated that the FctA structure is more favorable for linkage to FctA. In addition, the heterodimer formation of FctB with Cpa or FctA was shown to be mediated by the putative chaperone SipA. Together, these findings provide an alternative FctB structure as well as insight into the interactions between pilin proteins.
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Grants
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
- 19K22715, 19H03825, 22H03262, 22H03263 JSPS KAKENHI Grants-in-Aid for Scientific Research
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Affiliation(s)
- Katsuki Takebe
- Department of Oral and Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
| | - Mamoru Suzuki
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
| | - Takeshi Sangawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, Japan
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, 18057, Rostock, Germany
| | - Masaya Yamaguchi
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Bioinformatics Research Unit, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Bioinformatics Center, Research Institute for Microbial Diseases, Osaka University, 3-1, Yamadaoka, Suita, Osaka, Japan
- Center for Infectious Diseases Education and Research, Osaka University, 2-8, Yamadaoka, Suita, Osaka, Japan
| | - Narikazu Uzawa
- Department of Oral and Maxillofacial Oncology and Surgery, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
| | - Tomoko Sumitomo
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Department of Oral Microbiology, Graduate School of Biomedical Sciences, Tokushima University, 3-18-15, Kuramoto-cho, Tokushima, Japan
| | - Shigetada Kawabata
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan
- Center for Infectious Diseases Education and Research, Osaka University, 2-8, Yamadaoka, Suita, Osaka, Japan
| | - Masanobu Nakata
- Department of Microbiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Osaka, Japan.
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima, 890-8544, Japan.
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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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3
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Cotranslational Translocation and Folding of a Periplasmic Protein Domain in Escherichia coli. J Mol Biol 2021; 433:167047. [PMID: 33989648 DOI: 10.1016/j.jmb.2021.167047] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 04/13/2021] [Accepted: 05/04/2021] [Indexed: 01/26/2023]
Abstract
In Gram-negative bacteria, periplasmic domains in inner membrane proteins are cotranslationally translocated across the inner membrane through the SecYEG translocon. To what degree such domains also start to fold cotranslationally is generally difficult to determine using currently available methods. Here, we apply Force Profile Analysis (FPA) - a method where a translational arrest peptide is used to detect folding-induced forces acting on the nascent polypeptide - to follow the cotranslational translocation and folding of the large periplasmic domain of the E. coli inner membrane protease LepB in vivo. Membrane insertion of LepB's two N-terminal transmembrane helices is initiated when their respective N-terminal ends reach 45-50 residues away from the peptidyl transferase center (PTC) in the ribosome. The main folding transition in the periplasmic domain involves all but the ~15 most C-terminal residues of the protein and happens when the C-terminal end of the folded part is ~70 residues away from the PTC; a smaller putative folding intermediate is also detected. This implies that wildtype LepB folds post-translationally in vivo, and shows that FPA can be used to study both co- and post-translational protein folding in the periplasm.
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4
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Nakata M, Kreikemeyer B. Genetics, Structure, and Function of Group A Streptococcal Pili. Front Microbiol 2021; 12:616508. [PMID: 33633705 PMCID: PMC7900414 DOI: 10.3389/fmicb.2021.616508] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/18/2021] [Indexed: 12/12/2022] Open
Abstract
Streptococcus pyogenes (Group A Streptococcus; GAS) is an exclusively human pathogen. This bacterial species is responsible for a large variety of infections, ranging from purulent but mostly self-limiting oropharynx/skin diseases to streptococcal sequelae, including glomerulonephritis and rheumatic fever, as well as life-threatening streptococcal toxic-shock syndrome. GAS displays a wide array of surface proteins, with antigenicity of the M protein and pili utilized for M- and T-serotyping, respectively. Since the discovery of GAS pili in 2005, their genetic features, including regulation of expression, and structural features, including assembly mechanisms and protein conformation, as well as their functional role in GAS pathogenesis have been intensively examined. Moreover, their potential as vaccine antigens has been studied in detail. Pilus biogenesis-related genes are located in a discrete section of the GAS genome encoding fibronectin and collagen binding proteins and trypsin-resistant antigens (FCT region). Based on the heterogeneity of genetic composition and DNA sequences, this region is currently classified into nine distinguishable forms. Pili and fibronectin-binding proteins encoded in the FCT region are known to be correlated with infection sites, such as the skin and throat, possibly contributing to tissue tropism. As also found for pili of other Gram-positive bacterial pathogens, GAS pilin proteins polymerize via isopeptide bonds, while intramolecular isopeptide bonds present in the pilin provide increased resistance to degradation by proteases. As supported by findings showing that the main subunit is primarily responsible for T-serotyping antigenicity, pilus functions and gene expression modes are divergent. GAS pili serve as adhesins for tonsillar tissues and keratinocyte cell lines. Of note, a minor subunit is considered to have a harpoon function by which covalent thioester bonds with host ligands are formed. Additionally, GAS pili participate in biofilm formation and evasion of the immune system in a serotype/strain-specific manner. These multiple functions highlight crucial roles of pili during the onset of GAS infection. This review summarizes the current state of the art regarding GAS pili, including a new mode of host-GAS interaction mediated by pili, along with insights into pilus expression in terms of tissue tropism.
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Affiliation(s)
- Masanobu Nakata
- Department of Oral Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University of Rostock, Rostock, Germany
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5
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Wagachchi D, Tsai JYC, Chalmers C, Blanchett S, Loh JMS, Proft T. PilVax - a novel peptide delivery platform for the development of mucosal vaccines. Sci Rep 2018; 8:2555. [PMID: 29416095 PMCID: PMC5803258 DOI: 10.1038/s41598-018-20863-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/25/2018] [Indexed: 02/02/2023] Open
Abstract
Peptide vaccines are an attractive strategy to engineer the induction of highly targeted immune responses and avoid potentially allergenic and/or reactogenic protein regions. However, peptides by themselves are often unstable and poorly immunogenic, necessitating the need for an adjuvant and a specialised delivery system. We have developed a novel peptide delivery platform (PilVax) that allows the presentation of a stabilised and highly amplified peptide as part of the group A streptococcus serotype M1 pilus structure (PilM1) on the surface of the non-pathogenic bacterium Lactococcus lactis. To show proof of concept, we have successfully inserted the model peptide Ova324–339 into 3 different loop regions of the backbone protein Spy0128, which resulted in the assembly of the pilus containing large numbers of peptide on the surface of L. lactis. Intranasal immunisation of mice with L. lactis PilM1-Ova generated measurable Ova-specific systemic and mucosal responses (IgA and IgG). Furthermore, we show that multiple peptides can be inserted into the PilVax platform and that peptides can also be incorporated into structurally similar, but antigenically different pilus structures. PilVax may be useful as a cost-effective platform for the development of peptide vaccines against a variety of important human pathogens.
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Affiliation(s)
- Dasun Wagachchi
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand
| | - Jia-Yun C Tsai
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand
| | - Callum Chalmers
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand
| | - Sam Blanchett
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand
| | - Jacelyn M S Loh
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand.
| | - Thomas Proft
- Department of Molecular Medicine & Pathology, School of Medical Sciences, The University of Auckland, Auckland, 1023, New Zealand. .,Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, 1023, New Zealand.
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6
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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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7
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Estoppey D, Lee CM, Janoschke M, Lee BH, Wan KF, Dong H, Mathys P, Filipuzzi I, Schuhmann T, Riedl R, Aust T, Galuba O, McAllister G, Russ C, Spiess M, Bouwmeester T, Bonamy GM, Hoepfner D. The Natural Product Cavinafungin Selectively Interferes with Zika and Dengue Virus Replication by Inhibition of the Host Signal Peptidase. Cell Rep 2017; 19:451-460. [DOI: 10.1016/j.celrep.2017.03.071] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 03/06/2017] [Accepted: 03/24/2017] [Indexed: 12/31/2022] Open
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8
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A Type I Signal Peptidase Is Required for Pilus Assembly in the Gram-Positive, Biofilm-Forming Bacterium Actinomyces oris. J Bacteriol 2016; 198:2064-73. [PMID: 27215787 DOI: 10.1128/jb.00353-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/15/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED The Gram-positive bacterium Actinomyces oris, a key colonizer in the development of oral biofilms, contains 18 LPXTG motif-containing proteins, including fimbrillins that constitute two fimbrial types critical for adherence, biofilm formation, and polymicrobial interactions. Export of these protein precursors, which harbor a signal peptide, is thought to be mediated by the Sec machine and require cleavage of the signal peptide by type I signal peptidases (SPases). Like many Gram-positive bacteria, A. oris expresses two SPases, named LepB1 and LepB2. The latter has been linked to suppression of lethal "glyco-stress," caused by membrane accumulation of the LPXTG motif-containing glycoprotein GspA when the housekeeping sortase srtA is genetically disrupted. Consistent with this finding, we show here that a mutant lacking lepB2 and srtA was unable to produce high levels of glycosylated GspA and hence was viable. However, deletion of neither lepB1 nor lepB2 abrogated the signal peptide cleavage and glycosylation of GspA, indicating redundancy of SPases for GspA. In contrast, the lepB2 deletion mutant failed to assemble the wild-type levels of type 1 and 2 fimbriae, which are built by the shaft fimbrillins FimP and FimA, respectively; this phenotype was attributed to aberrant cleavage of the fimbrillin signal peptides. Furthermore, the lepB2 mutants, including the catalytically inactive S101A and K169A variants, exhibited significant defects in polymicrobial interactions and biofilm formation. Conversely, lepB1 was dispensable for the aforementioned processes. These results support the idea that LepB2 is specifically utilized for processing of fimbrial proteins, thus providing an experimental model with which to study the basis of type I SPase specificity. IMPORTANCE Sec-mediated translocation of bacterial protein precursors across the cytoplasmic membrane involves cleavage of their signal peptide by a signal peptidase (SPase). Like many Gram-positive bacteria, A. oris expresses two SPases, LepB1 and LepB2. The latter is a genetic suppressor of lethal "glyco-stress" caused by membrane accumulation of glycosylated GspA when the housekeeping sortase srtA is genetically disrupted. We show here that LepB1 and LepB2 are capable of processing GspA, whereas only LepB2 is required for cleavage of fimbrial signal peptides. This is the first example of a type I SPase dedicated to LPXTG motif-containing fimbrial proteins. Thus, A. oris provides an experimental model with which to investigate the specificity mechanism of type I SPases.
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9
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Douillard FP, Rasinkangas P, Bhattacharjee A, Palva A, de Vos WM. The N-Terminal GYPSY Motif Is Required for Pilin-Specific Sortase SrtC1 Functionality in Lactobacillus rhamnosus Strain GG. PLoS One 2016; 11:e0153373. [PMID: 27070897 PMCID: PMC4829219 DOI: 10.1371/journal.pone.0153373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/29/2016] [Indexed: 12/31/2022] Open
Abstract
Predominantly identified in pathogenic Gram-positive bacteria, sortase-dependent pili are also found in commensal species, such as the probiotic-marketed strain Lactobacillus rhamnosus strain GG. Pili are typically associated with host colonization, immune signalling and biofilm formation. Comparative analysis of the N-terminal domains of pilin-specific sortases from various piliated Gram-positive bacteria identified a conserved motif, called GYPSY, within the signal sequence. We investigated the function and role of the GYPSY residues by directed mutagenesis in homologous (rod-shaped) and heterologous (coccoid-shaped) expression systems for pilus formation. Substitutions of some of the GYPSY residues, and more specifically the proline residue, were found to have a direct impact on the degree of piliation of Lb. rhamnosus GG. The present findings uncover a new signalling element involved in the functionality of pilin-specific sortases controlling the pilus biogenesis of Lb. rhamnosus GG and related piliated Gram-positive species.
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Affiliation(s)
- François P. Douillard
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- * E-mail: (FPD); (WMdV)
| | - Pia Rasinkangas
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Arnab Bhattacharjee
- Research Programs Unit Immunobiology, Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
| | - Airi Palva
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Willem M. de Vos
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Research Programs Unit Immunobiology, Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
- * E-mail: (FPD); (WMdV)
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10
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Shaik MM, Lombardi C, Maragno Trindade D, Fenel D, Schoehn G, Di Guilmi AM, Dessen A. A structural snapshot of type II pilus formation in Streptococcus pneumoniae. J Biol Chem 2015. [PMID: 26198632 DOI: 10.1074/jbc.m115.647834] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pili are fibrous appendages expressed on the surface of a vast number of bacterial species, and their role in surface adhesion is important for processes such as infection, colonization, andbiofilm formation. The human pathogen Streptococcus pneumoniae expresses two different types of pili, PI-1 and PI-2, both of which require the concerted action of structural proteins and sortases for their polymerization. The type PI-1 streptococcal pilus is a complex, well studied structure, but the PI-2 type, present in a number of invasive pneumococcal serotypes, has to date remained less well understood. The PI-2 pilus consists of repeated units of a single protein, PitB, whose covalent association is catalyzed by cognate sortase SrtG-1 and partner protein SipA. Here we report the high resolution crystal structures of PitB and SrtG1 and use molecular modeling to visualize a "trapped" 1:1 complex between the two molecules. X-ray crystallography and electron microscopy reveal that the pneumococcal PI-2 backbone fiber is formed by PitB monomers associated in head-to-tail fashion and that short, flexible fibers can be formed even in the absence of coadjuvant proteins. These observations, obtained with a simple pilus biosynthetic system, are likely to be applicable to other fiber formation processes in a variety of Gram-positive organisms.
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Affiliation(s)
- Md Munan Shaik
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and
| | - Charlotte Lombardi
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and
| | - Daniel Maragno Trindade
- Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, 13083 São Paulo, Brazil
| | - Daphna Fenel
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and
| | - Guy Schoehn
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and
| | - Anne Marie Di Guilmi
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and
| | - Andréa Dessen
- From the Université Grenoble Alpes, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France, CNRS, IBS, 38044 Grenoble, France, Commissariat à l'Energie Atomique, IBS, Grenoble, France, and Brazilian National Laboratory for Biosciences (LNBio), CNPEM, Campinas, 13083 São Paulo, Brazil
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11
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Generic determinants of Streptococcus colonization and infection. INFECTION GENETICS AND EVOLUTION 2015; 33:361-70. [DOI: 10.1016/j.meegid.2014.09.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/10/2014] [Accepted: 09/14/2014] [Indexed: 11/20/2022]
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12
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Danger JL, Cao TN, Cao TH, Sarkar P, Treviño J, Pflughoeft KJ, Sumby P. The small regulatory RNA FasX enhances group A Streptococcus virulence and inhibits pilus expression via serotype-specific targets. Mol Microbiol 2015; 96:249-62. [PMID: 25586884 DOI: 10.1111/mmi.12935] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2015] [Indexed: 12/31/2022]
Abstract
Bacterial pathogens commonly show intra-species variation in virulence factor expression and often this correlates with pathogenic potential. The group A Streptococcus (GAS) produces a small regulatory RNA (sRNA), FasX, which regulates the expression of pili and the thrombolytic agent streptokinase. As GAS serotypes are polymorphic regarding (a) FasX abundance, (b) the fibronectin, collagen, T-antigen (FCT) region of the genome, which contains the pilus genes (nine different FCT-types), and (c) the streptokinase-encoding gene (ska) sequence (two different alleles), we sought to test whether FasX regulates pilus and streptokinase expression in a serotype-specific manner. Parental, fasX mutant and complemented derivatives of serotype M1 (ska-2, FCT-2), M2 (ska-1, FCT-6), M6 (ska-2, FCT-1) and M28 (ska-1, FCT-4) isolates were compared. While FasX reduced pilus expression in each serotype, the molecular basis differed, as FasX bound, and inhibited the translation of, different FCT-region mRNAs. FasX enhanced streptokinase expression in each serotype, although the degree of regulation varied. Finally, we established that the regulation afforded by FasX enhances GAS virulence, assessed by a model of bacteremia using human plasminogen-expressing mice. Our data are the first to identify and characterize serotype-specific regulation by an sRNA in GAS, and to show an sRNA directly contributes to GAS virulence.
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Affiliation(s)
- Jessica L Danger
- Center for Molecular Medicine, Department of Microbiology & Immunology, University of Nevada, School of Medicine, Reno, Nevada, USA
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