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Abstract
Recent efforts have re-invigorated the Streptococcus pyogenes (Group A Streptococcus) vaccine development field, though scientific, regulatory and commercial barriers persist, and the vaccine pipeline remains sparse. There is an ongoing need to accelerate all aspects of development to address the large global burden of disease caused by the pathogen. Building on over 100 years of S. pyogenes vaccine development, there are currently eight candidates on a product development track, including four M protein-based candidates and four candidates designed around non-M protein antigens. These candidates have demonstrated proof of concept for protection against S. pyogenes in preclinical models, one has demonstrated safety and immunogenicity in a Phase 1 trial and at least four others are poised to soon enter clinical trials. To maintain momentum, the Strep A Vaccine Global Consortium (SAVAC) was established to bring together experts to accelerate global S. pyogenes vaccine development. This article highlights the past, present and future of S. pyogenes vaccine development and emphasizes key priorities, and the role of SAVAC, in advancing the field.
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M.tb-Rv2462c of Mycobacterium tuberculosis Shows Chaperone-like Activity and Plays a Role in Stress Adaptation and Immunomodulation. BIOLOGY 2022; 12:biology12010069. [PMID: 36671761 PMCID: PMC9855790 DOI: 10.3390/biology12010069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/28/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Mycobacterium tuberculosis (M.tb)-encoded factors protect it against host-generated stresses and support its survival in the hostile host environment. M.tb possesses two peptidyl-prolyl cis-trans isomerases and a probable trigger factor encoded by Rv2462c which has an FKBP-like PPIase domain. PPIases are known to assist the folding of peptidyl-prolyl bonds and are involved in various cellular processes important for bacterial survival in host-generated stresses. In this study, we aim to functionally characterize Rv2462c of M.tb. Our data suggest that the trigger factor of M.tb exhibits chaperone activity both in vitro and in vivo. Heterologous expression of M.tb-Rv2462c locus into Mycobacterium smegmatis enhanced its survival within macrophages, adaptation to oxidative stress and biofilm formation. M.tb-trigger factor has strong immunomodulatory potential and modifies the cytokine profile of the host towards the proinflammatory axis.
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The Phosphatase Bph and Peptidyl-Prolyl Isomerase PrsA Are Required for Gelatinase Expression and Activity in Enterococcus faecalis. J Bacteriol 2022; 204:e0012922. [PMID: 35657705 DOI: 10.1128/jb.00129-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecalis is a common commensal bacterium in the gastrointestinal tract as well as a frequent nosocomial pathogen. The secreted metalloprotease gelatinase (GelE) is an important E. faecalis virulence factor that contributes to numerous cellular activities, such as autolysis, biofilm formation, and biofilm-associated antibiotic resistance. Expression of gelE has been extensively studied and is regulated by the Fsr quorum sensing system. Here, we identify two additional factors regulating gelatinase expression and activity in E. faecalis OG1RF. The Bph phosphatase is required for expression of gelE in an Fsr-dependent manner. Additionally, the membrane-anchored protein foldase PrsA is required for GelE activity, but not fsr or gelE gene expression. Disrupting prsA also leads to increased antibiotic sensitivity in biofilms independent of the loss of GelE activity. Together, our results expand the model for gelatinase production in E. faecalis, which has important implications for fundamental studies of GelE function in Enterococcus and also E. faecalis pathogenesis. IMPORTANCE In Enterococcus faecalis, gelatinase (GelE) is a virulence factor that is also important for biofilm formation and interactions with other microbes as well as the host immune system. The long-standing model for GelE production is that the Fsr quorum sensing system positively regulates expression of gelE. Here, we update that model by identifying two additional factors that contribute to gelatinase production. The biofilm-associated Bph phosphatase regulates the expression of gelE through Fsr, and the peptidyl-prolyl isomerase PrsA is required for production of active GelE through an Fsr-independent mechanism. This provides important insight into how regulatory networks outside of the fsr locus coordinate expression of gelatinase.
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Awussi AA, Roux E, Humeau C, Hafeez Z, Maigret B, Chang OK, Lecomte X, Humbert G, Miclo L, Genay M, Perrin C, Dary-Mourot A. Role of the Sortase A in the Release of Cell-Wall Proteinase PrtS in the Growth Medium of Streptococcus thermophilus 4F44. Microorganisms 2021; 9:microorganisms9112380. [PMID: 34835505 PMCID: PMC8623714 DOI: 10.3390/microorganisms9112380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/04/2021] [Accepted: 11/13/2021] [Indexed: 11/16/2022] Open
Abstract
Growth of the lactic acid bacterium Streptococcus thermophilus in milk depends on its capacity to hydrolyze proteins of this medium through its surface proteolytic activity. Thus, strains exhibiting the cell envelope proteinase (CEP) PrtS are able to grow in milk at high cellular density. Due to its LPNTG motif, which is possibly the substrate of the sortase A (SrtA), PrtS is anchored to the cell wall in most S. thermophilus strains. Conversely, a soluble extracellular PrtS activity has been reported in the strain 4F44. It corresponds, in fact, to a certain proportion of PrtS that is not anchored to the cell wall but rather is released in the growth medium. The main difference between PrtS of strain 4F44 (PrtS4F44) and other PrtS concerns the absence of a 32-residue imperfect duplication in the prodomain of the CEP, postulated as being required for the maturation and correct subsequent anchoring of PrtS. In fact, both mature (without the prodomain at the N-terminal extremity) and immature (with the prodomain) forms are found in the soluble PrtS4F44 form along with an intact LPNTG at their C-terminal extremity. Investigations we present in this work show that (i) the imperfect duplication is not implied in PrtS maturation; (ii) the maturase PrtM is irrelevant in PrtS maturation which is probably automaturated; and (iii) SrtA allows for the PrtS anchoring in S. thermophilus but the SrtA of strain 4F44 (SrtA4F44) displays an altered activity.
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Affiliation(s)
- Ahoefa Ablavi Awussi
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Emeline Roux
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | | | - Zeeshan Hafeez
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Bernard Maigret
- CNRS, Inria, LORIA, Université de Lorraine, F-54000 Nancy, France;
| | - Oun Ki Chang
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
- Hazard Substance Analysis Division, Gwangju Regional Office of Food and Drug Safety, Gwangju 10031, Korea
| | - Xavier Lecomte
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Gérard Humbert
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Laurent Miclo
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Magali Genay
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Clarisse Perrin
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
| | - Annie Dary-Mourot
- CALBINOTOX, Université de Lorraine, F-54000 Nancy, France; (A.A.A.); (E.R.); (Z.H.); (O.K.C.); (X.L.); (G.H.); (L.M.); (M.G.); (C.P.)
- Correspondence:
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5
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Staphylococcus aureus Trigger Factor Is Involved in Biofilm Formation and Cooperates with the Chaperone PpiB. J Bacteriol 2021; 203:JB.00681-20. [PMID: 33468596 DOI: 10.1128/jb.00681-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that assist in protein folding around proline-peptide bonds, and they often possess chaperone activity. Staphylococcus aureus encodes three PPIases, i.e., PrsA, PpiB, and trigger factor (TF). Previous work by our group demonstrated a role for both PrsA and PpiB in S. aureus; however, TF remains largely unstudied. Here, we identify a role for TF in S. aureus biofilm formation and demonstrate cooperation between TF and the cytoplasmic PPIase PpiB. Mutation of the tig gene (encoding TF) led to reduced biofilm development in vitro but no significant attenuation of virulence in a mouse model of infection. To investigate whether TF possesses chaperone activity, we analyzed the ability of a tig mutant to survive acid and base stress. While there was no significant decrease for a tig mutant, a ppiB tig double mutant exhibited significant decreases in cell viability after acid and base challenges. We then demonstrated that a ppiB tig double mutant had exacerbated phenotypes in vitro and in vivo, compared to either single mutant. Finally, in vivo immunoprecipitation of epitope-tagged PpiB revealed that PpiB interacted with 4 times the number of proteins when TF was absent from the cell, suggesting that it may be compensating for the loss of TF. Interestingly, the only proteins found to interact with TF were TF itself, fibronectin-binding protein B (FnBPB), and the chaperone protein ClpB. Collectively, these results support the first phenotype for S. aureus TF and demonstrate a greater network of cooperation between chaperone proteins in Staphylococcus aureus IMPORTANCE S. aureus encodes a large number of virulence factors that aid the bacterium in survival and pathogenesis. These virulence factors have a wide variety of functions; however, they must all be properly secreted in order to be functional. Bacterial chaperone proteins often assist in secretion by trafficking proteins to secretion machinery or assisting in proper protein folding. Here, we report that the S. aureus chaperone TF contributes to biofilm formation and cooperates with the chaperone PpiB to regulate S. aureus virulence processes. These data highlight the first known role for TF in S. aureus and suggest that S. aureus chaperone proteins may be involved in a greater regulatory network in the cell.
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Scheuplein NJ, Bzdyl NM, Kibble EA, Lohr T, Holzgrabe U, Sarkar-Tyson M. Targeting Protein Folding: A Novel Approach for the Treatment of Pathogenic Bacteria. J Med Chem 2020; 63:13355-13388. [PMID: 32786507 DOI: 10.1021/acs.jmedchem.0c00911] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Infectious diseases are a major cause of morbidity and mortality worldwide, exacerbated by increasing antibiotic resistance in many bacterial species. The development of drugs with new modes of action is essential. A leading strategy is antivirulence, with the aim to target bacterial proteins that are important in disease causation and progression but do not affect growth, resulting in reduced selective pressure for resistance. Immunophilins, a superfamily of peptidyl-prolyl cis-trans isomerase (PPIase) enzymes have been shown to be important for virulence in a broad-spectrum of pathogenic bacteria. This Perspective will provide an overview of the recent advances made in understanding the role of each immunophilin family, cyclophilins, FK506 binding proteins (FKBPs), and parvulins in bacteria. Inhibitor design and medicinal chemistry strategies for development of novel drugs against bacterial FKBPs will be discussed. Furthermore, drugs against human cyclophilins and parvulins will be reviewed in their current indication as antiviral and anticancer therapies.
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Affiliation(s)
- Nicolas J Scheuplein
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Nicole M Bzdyl
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia
| | - Emily A Kibble
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia.,School of Veterinary and Life Sciences, Murdoch University, 6150 Murdoch, Australia
| | - Theresa Lohr
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Mitali Sarkar-Tyson
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, 6009 Perth, Australia
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Profiling of Turkish propolis subtypes: Comparative evaluation of their phytochemical compositions, antioxidant and antimicrobial activities. Lebensm Wiss Technol 2018. [DOI: 10.1016/j.lwt.2018.04.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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An Intracellular Peptidyl-Prolyl cis/trans Isomerase Is Required for Folding and Activity of the Staphylococcus aureus Secreted Virulence Factor Nuclease. J Bacteriol 2016; 199:JB.00453-16. [PMID: 27795319 DOI: 10.1128/jb.00453-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/04/2016] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is an important human pathogen that relies on a large repertoire of secreted and cell wall-associated proteins for pathogenesis. Consequently, the ability of the organism to cause disease is absolutely dependent on its ability to synthesize and successfully secrete these proteins. In this study, we investigate the role of peptidyl-prolyl cis/trans isomerases (PPIases) on the activity of the S. aureus secreted virulence factor nuclease (Nuc). We identify a staphylococcal cyclophilin-type PPIase (PpiB) that is required for optimal activity of Nuc. Disruption of ppiB results in decreased nuclease activity in culture supernatants; however, the levels of Nuc protein are not altered, suggesting that the decrease in activity results from misfolding of Nuc in the absence of PpiB. We go on to demonstrate that PpiB exhibits PPIase activity in vitro, is localized to the bacterial cytosol, and directly interacts with Nuc in vitro to accelerate the rate of Nuc refolding. Finally, we demonstrate an additional role for PpiB in S. aureus hemolysis and demonstrate that the S. aureus parvulin-type PPIase PrsA also plays a role in the activity of secreted virulence factors. The deletion of prsA leads to a decrease in secreted protease and phospholipase activity, similar to that observed in other Gram-positive pathogens. Together, these results demonstrate, for the first time to our knowledge, that PPIases play an important role in the secretion of virulence factors in S. aureus IMPORTANCE: Staphylococcus aureus is a highly dangerous bacterial pathogen capable of causing a variety of infections throughout the human body. The ability of S. aureus to cause disease is largely due to an extensive repertoire of secreted and cell wall-associated proteins, including adhesins, toxins, exoenzymes, and superantigens. These virulence factors, once produced, are typically transported across the cell membrane by the secretory (Sec) system in a denatured state. Consequently, once outside the cell, they must refold into their active form. This step often requires the assistance of bacterial folding proteins, such as PPIases. In this work, we investigate the role of PPIases in S. aureus and uncover a cyclophilin-type enzyme that assists in the folding/refolding of staphylococcal nuclease.
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Abstract
Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.
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10
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Cao C, Zhang F, Ji M, Pei F, Fan X, Shen H, Wang Q, Yang W, Wang Y. Development of a loop-mediated isothermal amplification method for rapid detection of streptococcal pyrogenic exotoxin B. Toxicon 2016; 117:53-8. [DOI: 10.1016/j.toxicon.2016.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/24/2016] [Accepted: 03/31/2016] [Indexed: 11/30/2022]
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11
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The Activity of Escherichia coli Chaperone SurA Is Regulated by Conformational Changes Involving a Parvulin Domain. J Bacteriol 2016; 198:921-9. [PMID: 26728192 DOI: 10.1128/jb.00889-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/29/2015] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The periplasmic chaperone SurA is critical for the biogenesis of outer membrane proteins (OMPs) and, thus, the maintenance of membrane integrity in Escherichia coli. The activity of this modular chaperone has been attributed to a core chaperone module, with only minor importance assigned to the two SurA peptidyl-prolyl isomerase (PPIase) domains. In this work, we used synthetic phenotypes and covalent tethering to demonstrate that the activity of SurA is regulated by its PPIase domains and, furthermore, that its activity is correlated with the conformational state of the chaperone. When combined with mutations in the β-barrel assembly machine (BAM), SurA mutations resulting in deletion of the second parvulin domain (P2) inhibit OMP assembly, suggesting that P2 is involved in the regulation of SurA. The first parvulin domain (P1) potentiates this autoinhibition, as mutations that covalently tether the P1 domain to the core chaperone module severely impair OMP assembly. Furthermore, these inhibitory mutations negate the suppression of and biochemically stabilize the protein specified by a well-characterized gain-of-function mutation in P1, demonstrating that SurA cycles between distinct conformational and functional states during the OMP assembly process. IMPORTANCE This work reveals the reversible autoinhibition of the SurA chaperone imposed by a heretofore underappreciated parvulin domain. Many β-barrel-associated outer membrane (OM) virulence factors, including the P-pilus and type I fimbriae, rely on SurA for proper assembly; thus, a mechanistic understanding of SurA function and inhibition may facilitate antibiotic intervention against Gram-negative pathogens, such as uropathogenic Escherichia coli, E. coli O157:H7, Shigella, and Salmonella. In addition, SurA is important for the assembly of critical OM biogenesis factors, such as the lipopolysaccharide (LPS) transport machine, suggesting that specific targeting of SurA may provide a useful means to subvert the OM barrier.
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12
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Persson H, Söderberg JJ, Vindebro R, Johansson BP, von Pawel-Rammingen U. Proteolytic processing of the streptococcal IgG endopeptidase IdeS modulates the functional properties of the enzyme and results in reduced immunorecognition. Mol Immunol 2015; 68:176-84. [DOI: 10.1016/j.molimm.2015.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 01/01/2023]
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13
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Crowley PJ, Brady LJ. Evaluation of the effects of Streptococcus mutans chaperones and protein secretion machinery components on cell surface protein biogenesis, competence, and mutacin production. Mol Oral Microbiol 2015; 31:59-77. [PMID: 26386361 DOI: 10.1111/omi.12130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2015] [Indexed: 11/29/2022]
Abstract
The respective contributions of components of the protein translocation/maturation machinery to cell surface biogenesis in Streptococcus mutans are not fully understood. Here we used a genetic approach to characterize the effects of deletion of genes encoding the ribosome-associated chaperone RopA (Trigger Factor), the surface-localized foldase PrsA, and the membrane-localized chaperone insertases YidC1 and YidC2, both singly and in combination, on bacterial growth, chain length, self-aggregation, cell surface hydrophobicity, autolysis, and antigenicity of surface proteins P1 (AgI/II, PAc), WapA, GbpC, and GtfD. The single and double deletion mutants, as well as additional mutant strains lacking components of the signal recognition particle pathway, were also evaluated for their effects on mutacin production and genetic competence.
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Affiliation(s)
- P J Crowley
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - L J Brady
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
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Microbial peptidyl-prolyl cis/trans isomerases (PPIases): virulence factors and potential alternative drug targets. Microbiol Mol Biol Rev 2015; 78:544-71. [PMID: 25184565 DOI: 10.1128/mmbr.00015-14] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Initially discovered in the context of immunomodulation, peptidyl-prolyl cis/trans isomerases (PPIases) were soon identified as enzymes catalyzing the rate-limiting protein folding step at peptidyl bonds preceding proline residues. Intense searches revealed that PPIases are a superfamily of proteins consisting of three structurally distinguishable families with representatives in every described species of prokaryote and eukaryote and, recently, even in some giant viruses. Despite the clear-cut enzymatic activity and ubiquitous distribution of PPIases, reports on solely PPIase-dependent biological roles remain scarce. Nevertheless, they have been found to be involved in a plethora of biological processes, such as gene expression, signal transduction, protein secretion, development, and tissue regeneration, underscoring their general importance. Hence, it is not surprising that PPIases have also been identified as virulence-associated proteins. The extent of contribution to virulence is highly variable and dependent on the pleiotropic roles of a single PPIase in the respective pathogen. The main objective of this review is to discuss this variety in virulence-related bacterial and protozoan PPIases as well as the involvement of host PPIases in infectious processes. Moreover, a special focus is given to Legionella pneumophila macrophage infectivity potentiator (Mip) and Mip-like PPIases of other pathogens, as the best-characterized virulence-related representatives of this family. Finally, the potential of PPIases as alternative drug targets and first tangible results are highlighted.
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15
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Ünal CM, Steinert M. FKBPs in bacterial infections. Biochim Biophys Acta Gen Subj 2014; 1850:2096-102. [PMID: 25529296 DOI: 10.1016/j.bbagen.2014.12.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/11/2014] [Accepted: 12/13/2014] [Indexed: 02/05/2023]
Abstract
BACKGROUND FK506-binding proteins (FKBPs) contain a domain with peptidyl-prolyl-cis/trans-isomerase (PPIase) activity and bind the immunosuppressive drugs FK506 and rapamycin. FKBPs belong to the immunophilin family and are found in eukaryotes and bacteria. SCOPE OF REVIEW In this review we describe two major groups of bacterial virulence-associated FKBPs, the trigger factor and Mip-like PPIases. Moreover, we discuss the contribution of host FKBPs in bacterial infection processes. MAJOR CONCLUSIONS Since PPIases are regarded as alternative antiinfective drug targets we highlight current research strategies utilizing pipecolinic acid and cycloheximide derivatives as well as substrate based inhibitors. GENERAL SIGNIFICANCE The current research strategies suggest a beneficial synergism of drug development and basic research. This article is part of a Special Issue entitled Proline-directed Foldases: Cell Signaling Catalysts and Drug Targets.
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Affiliation(s)
- Can M Ünal
- Türk-Alman Üniversitesi, Fen Fakültesi, Istanbul, Turkey; Technische Universität Braunschweig, Institut für Mikrobiologie, Braunschweig, Germany
| | - Michael Steinert
- Technische Universität Braunschweig, Institut für Mikrobiologie, Braunschweig, Germany; Helmholtz Centre for Infection Research, Braunschweig, Germany.
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Peptidylprolyl cis–trans isomerases of Legionella pneumophila: virulence, moonlighting and novel therapeutic targets. Biochem Soc Trans 2014; 42:1728-33. [DOI: 10.1042/bst20140202] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Legionella pneumophila, typically a parasite of free-living protozoa, can also replicate in human alveolar macrophages and lung epithelial cells causing Legionnaires’ disease in humans, a severe atypical pneumonia. The pathogen encodes six peptidylprolyl cis–trans isomerases (PPIases), which generally accelerate folding of prolyl peptide bonds, and influence protein folding. PPIases can be divided into three classes, cyclophilins, parvulins and FK506-binding proteins (FKBPs). They contribute to a multitude of cellular functions including bacterial virulence. In the present review, we provide an overview of L. pneumophila PPIases, discussing their known and anticipated functions as well as moonlighting phenomena. By taking the example of the macrophage infectivity potentiator (Mip) of L. pneumophila, we highlight the potential of PPIases as promising drug targets.
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17
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Papadimitriou K, Anastasiou R, Mavrogonatou E, Blom J, Papandreou NC, Hamodrakas SJ, Ferreira S, Renault P, Supply P, Pot B, Tsakalidou E. Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex. BMC Genomics 2014; 15:272. [PMID: 24713045 PMCID: PMC4051162 DOI: 10.1186/1471-2164-15-272] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 04/01/2014] [Indexed: 12/21/2022] Open
Abstract
Background Within the genus Streptococcus, only Streptococcus
thermophilus is used as a starter culture in food fermentations.
Streptococcus macedonicus though, which belongs to the
Streptococcus bovis/Streptococcus equinus complex
(SBSEC), is also frequently isolated from fermented foods mainly of dairy
origin. Members of the SBSEC have been implicated in human endocarditis and
colon cancer. Here we compare the genome sequence of the dairy isolate
S. macedonicus ACA-DC 198 to the other SBSEC genomes in order
to assess in silico its potential adaptation to milk and its
pathogenicity status. Results Despite the fact that the SBSEC species were found tightly related based on
whole genome phylogeny of streptococci, two distinct patterns of evolution
were identified among them. Streptococcus macedonicus, Streptococcus
infantarius CJ18 and Streptococcus pasteurianus ATCC 43144
seem to have undergone reductive evolution resulting in significantly
diminished genome sizes and increased percentages of potential pseudogenes
when compared to Streptococcus gallolyticus subsp.
gallolyticus. In addition, the three species seem to have lost
genes for catabolizing complex plant carbohydrates and for detoxifying toxic
substances previously linked to the ability of S. gallolyticus to
survive in the rumen. Analysis of the S. macedonicus genome
revealed features that could support adaptation to milk, including an extra
gene cluster for lactose and galactose metabolism, a proteolytic system for
casein hydrolysis, auxotrophy for several vitamins, an increased ability to
resist bacteriophages and horizontal gene transfer events with the dairy
Lactococcus lactis and S. thermophilus as potential
donors. In addition, S. macedonicus lacks several
pathogenicity-related genes found in S. gallolyticus. For example,
S. macedonicus has retained only one (i.e. the pil3)
of the three pilus gene clusters which may mediate the binding of S.
gallolyticus to the extracellular matrix. Unexpectedly, similar
findings were obtained not only for the dairy S. infantarius CJ18,
but also for the blood isolate S. pasteurianus ATCC 43144. Conclusions Our whole genome analyses suggest traits of adaptation of S.
macedonicus to the nutrient-rich dairy environment. During this
process the bacterium gained genes presumably important for this new
ecological niche. Finally, S. macedonicus carries a reduced number
of putative SBSEC virulence factors, which suggests a diminished pathogenic
potential.
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Affiliation(s)
- Konstantinos Papadimitriou
- Laboratory of Dairy Research, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, Athens 118 55, Greece.
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18
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Zhang BC, Zhang J, Sun L. Streptococcus iniae SF1: complete genome sequence, proteomic profile, and immunoprotective antigens. PLoS One 2014; 9:e91324. [PMID: 24621602 PMCID: PMC3951389 DOI: 10.1371/journal.pone.0091324] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/10/2014] [Indexed: 01/06/2023] Open
Abstract
Streptococcus iniae is a Gram-positive bacterium that is reckoned one of the most severe aquaculture pathogens. It has a broad host range among farmed marine and freshwater fish and can also cause zoonotic infection in humans. Here we report for the first time the complete genome sequence as well as the host factor-induced proteomic profile of a pathogenic S. iniae strain, SF1, a serotype I isolate from diseased fish. SF1 possesses a single chromosome of 2,149,844 base pairs, which contains 2,125 predicted protein coding sequences (CDS), 12 rRNA genes, and 45 tRNA genes. Among the protein-encoding CDS are genes involved in resource acquisition and utilization, signal sensing and transduction, carbohydrate metabolism, and defense against host immune response. Potential virulence genes include those encoding adhesins, autolysins, toxins, exoenzymes, and proteases. In addition, two putative prophages and a CRISPR-Cas system were found in the genome, the latter containing a CRISPR locus and four cas genes. Proteomic analysis detected 21 secreted proteins whose expressions were induced by host serum. Five of the serum-responsive proteins were subjected to immunoprotective analysis, which revealed that two of the proteins were highly protective against lethal S. iniae challenge when used as purified recombinant subunit vaccines. Taken together, these results provide an important molecular basis for future study of S. iniae in various aspects, in particular those related to pathogenesis and disease control.
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Affiliation(s)
- Bao-cun Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Jian Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Collaborative Innovation Center of Deep Sea Biology, Zhejiang University, Hangzhou, China
- * E-mail:
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Castanié-Cornet MP, Bruel N, Genevaux P. Chaperone networking facilitates protein targeting to the bacterial cytoplasmic membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:1442-56. [PMID: 24269840 DOI: 10.1016/j.bbamcr.2013.11.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/10/2013] [Accepted: 11/13/2013] [Indexed: 12/22/2022]
Abstract
Nascent polypeptides emerging from the ribosome are assisted by a pool of molecular chaperones and targeting factors, which enable them to efficiently partition as cytosolic, integral membrane or exported proteins. Extensive genetic and biochemical analyses have significantly expanded our knowledge of chaperone tasking throughout this process. In bacteria, it is known that the folding of newly-synthesized cytosolic proteins is mainly orchestrated by three highly conserved molecular chaperones, namely Trigger Factor (TF), DnaK (HSP70) and GroEL (HSP60). Yet, it has been reported that these major chaperones are strongly involved in protein translocation pathways as well. This review describes such essential molecular chaperone functions, with emphasis on both the biogenesis of inner membrane proteins and the post-translational targeting of presecretory proteins to the Sec and the twin-arginine translocation (Tat) pathways. Critical interplay between TF, DnaK, GroEL and other molecular chaperones and targeting factors, including SecB, SecA, the signal recognition particle (SRP) and the redox enzyme maturation proteins (REMPs) is also discussed. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France
| | - Nicolas Bruel
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaire (LMGM), Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier, Toulouse, France.
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20
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Cho KH, Kang SO. Streptococcus pyogenes c-di-AMP phosphodiesterase, GdpP, influences SpeB processing and virulence. PLoS One 2013; 8:e69425. [PMID: 23869242 PMCID: PMC3711813 DOI: 10.1371/journal.pone.0069425] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 06/10/2013] [Indexed: 01/09/2023] Open
Abstract
Small cyclic nucleotide derivatives are employed as second messengers by both prokaryotes and eukaryotes to regulate diverse cellular processes responding to various signals. In bacteria, c-di-AMP has been discovered most recently, and some Gram-positive pathogens including S. pyogenes use this cyclic nucleotide derivative as a second messenger instead of c-di-GMP, a well-studied important bacterial second messenger. GdpP, c-di-AMP phosphodiesterase, is responsible for degrading c-di-AMP inside cells, and the cellular role of GdpP in S. pyogenes has not been examined yet. To test the cellular role of GdpP, we created a strain with a nonpolar inframe deletion of the gdpP gene, and examined the properties of the strain including virulence. From this study, we demonstrated that GdpP influences the biogenesis of SpeB, the major secreted cysteine protease, at a post-translational level, susceptibility to the beta lactam antibiotic ampicillin, and is necessary for full virulence in a murine subcutaneous infection model.
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Affiliation(s)
- Kyu Hong Cho
- Department of Microbiology, Southern Illinois University, Carbondale, Illinois, USA.
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21
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The streptococcal cysteine protease SpeB is not a natural immunoglobulin-cleaving enzyme. Infect Immun 2013; 81:2236-41. [PMID: 23569114 DOI: 10.1128/iai.00168-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The human bacterial pathogen Streptococcus pyogenes has developed a broad variety of virulence mechanisms to evade the actions of the host immune defense. One of the best-characterized factors is the streptococcal cysteine protease SpeB, an important multifunctional protease that contributes to group A streptococcal pathogenesis in vivo. Among many suggested activities, SpeB has been described to degrade various human plasma proteins, including immunoglobulins (Igs). In this study, we show that SpeB has no Ig-cleaving activity under physiological conditions and that only Igs in a reduced state, i.e., semimonomeric molecules, are cleaved and degraded by SpeB. Since reducing conditions outside eukaryotic cells have to be considered nonphysiological and IgG in a reduced state lacks biological effector functions, we conclude that SpeB does not contribute to S. pyogenes virulence through the proteolytic degradation of Igs.
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22
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Conserved anchorless surface proteins as group A streptococcal vaccine candidates. J Mol Med (Berl) 2012; 90:1197-207. [DOI: 10.1007/s00109-012-0897-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 03/25/2012] [Accepted: 03/26/2012] [Indexed: 10/28/2022]
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23
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Chang OK, Perrin C, Galia W, Saulnier F, Miclo L, Roux E, Driou A, Humbert G, Dary A. Release of the cell-envelope protease PrtS in the growth medium of Streptococcus thermophilus 4F44. Int Dairy J 2012. [DOI: 10.1016/j.idairyj.2011.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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24
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Abstract
Streptococcus pyogenes (group A streptococcus [GAS]) is a human-specific pathogen that causes a variety of diseases ranging from superficial infections to life-threatening diseases. SpeB, a potent extracellular cysteine proteinase, plays an important role in the pathogenesis of GAS infections. Previous studies show that SpeB expression and activity are controlled at the transcriptional and posttranslational levels, though it had been unclear whether speB was also regulated at the posttranscriptional level. In this study, we examined the growth phase-dependent speB mRNA level and decay using quantitative reverse transcription-PCR (qRT-PCR) and Northern blot analyses. We observed that speB mRNA accumulated rapidly during exponential growth, which occurred concomitantly with an increase in speB mRNA stability. A closer observation revealed that the increased speB mRNA stability was mainly due to progressive acidification. Inactivation of RNase Y, a recently identified endoribonuclease, revealed a role in processing and degradation of speB mRNA. We conclude that the increased speB mRNA stability contributes to the rapid accumulation of speB transcript during growth.
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25
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Henningham A, Gillen CM, Walker MJ. Group a streptococcal vaccine candidates: potential for the development of a human vaccine. Curr Top Microbiol Immunol 2012; 368:207-42. [PMID: 23250780 DOI: 10.1007/82_2012_284] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Currently there is no commercial Group A Streptococcus (GAS; S. pyogenes) vaccine available. The development of safe GAS vaccines is challenging, researchers are confronted with obstacles such as the occurrence of many unique serotypes (there are greater than 150 M types), antigenic variation within the same serotype, large variations in the geographical distribution of serotypes, and the production of antibodies cross-reactive with human tissue which can lead to host auto-immune disease. Cell wall anchored, cell membrane associated, secreted and anchorless proteins have all been targeted as GAS vaccine candidates. As GAS is an exclusively human pathogen, the quest for an efficacious vaccine is further complicated by the lack of an animal model which mimics human disease and can be consistently and reproducibly colonized by multiple GAS strains.
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Affiliation(s)
- Anna Henningham
- School of Chemistry and Molecular Biosciences and Australian Infectious Disease Research Centre, University of Queensland, St Lucia, QLD 4072, Australia
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26
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Carroll RK, Musser JM. From transcription to activation: how group A streptococcus, the flesh-eating pathogen, regulates SpeB cysteine protease production. Mol Microbiol 2011; 81:588-601. [PMID: 21707787 DOI: 10.1111/j.1365-2958.2011.07709.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Streptococcal pyrogenic exotoxin B (SpeB) is a protease secreted by group A streptococci and known to degrade a wide range of host and GAS proteins in vitro. Although the role of SpeB in GAS infection is debated, recent evidence has conclusively demonstrated that SpeB is critical for the pathogenesis of severe invasive disease caused by GAS. Genetic inactivation of the speB gene results in significantly decreased virulence in a necrotizing fasciitis model of infection. Production of fully active SpeB by GAS is extremely complex. Following transcription and translation the SpeB protein is secreted as an inactive zymogen, which is autocatalytically processed through a series of intermediates to form an active protease. Each step from transcription to protease activation is tightly controlled and regulated by the bacterial cell reflecting the critical role played by this virulence factor in GAS infection. Here we review the molecular aspects of SpeB production by GAS from transcription to activation and the multiple layers of control involved.
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Affiliation(s)
- Ronan K Carroll
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, Houston, TX 77030, USA
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27
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Carroll RK, Shelburne SA, Olsen RJ, Suber B, Sahasrabhojane P, Kumaraswami M, Beres SB, Shea PR, Flores AR, Musser JM. Naturally occurring single amino acid replacements in a regulatory protein alter streptococcal gene expression and virulence in mice. J Clin Invest 2011; 121:1956-68. [PMID: 21490401 DOI: 10.1172/jci45169] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 02/02/2011] [Indexed: 11/17/2022] Open
Abstract
Infection with different strains of the same species of bacteria often results in vastly different clinical outcomes. Despite extensive investigation, the genetic basis of microbial strain-specific virulence remains poorly understood. Recent whole-genome sequencing has revealed that SNPs are the most prevalent form of genetic diversity among different strains of the same species of bacteria. For invasive serotype M3 group A streptococci (GAS) strains, the gene encoding regulator of proteinase B (RopB) has the highest frequency of SNPs. Here, we have determined that ropB polymorphisms alter RopB function and modulate GAS host-pathogen interactions. Sequencing of ropB in 171 invasive serotype M3 GAS strains identified 19 distinct ropB alleles. Inactivation of the ropB gene in strains producing distinct RopB variants had dramatically divergent effects on GAS global gene expression. Additionally, generation of isoallelic GAS strains differing only by a single amino acid in RopB confirmed that variant proteins affected transcript levels of the gene encoding streptococcal proteinase B, a major RopB-regulated virulence factor. Comparison of parental, RopB-inactivated, and RopB isoallelic strains in mouse infection models demonstrated that ropB polymorphisms influence GAS virulence and disease manifestations. These data detail a paradigm in which unbiased, whole-genome sequence analysis of populations of clinical bacterial isolates creates new avenues of productive investigation into the pathogenesis of common human infections.
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Affiliation(s)
- Ronan K Carroll
- Center for Molecular and Translational Human Infectious Diseases Research, The Methodist Hospital Research Institute, and Department of Pathology and Laboratory Medicine, The Methodist Hospital, Houston, Texas, USA
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28
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Wu T, Zhao Z, Zhang L, Ma H, Lu K, Ren W, Liu Z, Chang H, Bei W, Qiu Y, Chen H. Trigger factor of Streptococcus suis is involved in stress tolerance and virulence. Microb Pathog 2010; 51:69-76. [PMID: 21093574 DOI: 10.1016/j.micpath.2010.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2010] [Revised: 10/08/2010] [Accepted: 10/10/2010] [Indexed: 02/03/2023]
Abstract
Streptococcus suis serotype 2 is an important zoonotic pathogen that causes serious diseases such as meningitis, septicemia, endocarditis, arthritis and septic shock in pigs and humans. Little is known about the regulation of virulence gene expression in S. suis serotype 2. In this study, we cloned and deleted the entire tig gene from the chromosome of S. suis serotype 2 SC21 strain, and constructed a mutant strain (Δtig) and a complementation strain (CΔtig). The results demonstrated that the tig gene, encoding trigger factor from S. suis serotype 2 SC21, affects the stress tolerance and the expression of a few virulence genes of S. suis serotype 2. Deletion of the tig gene of S. suis serotype 2 resulted in mutant strain, ΔTig, which exhibited a significant decrease in adherence to cell line HEp-2, and lacked hemolytic activity. Tig deficiency diminishes stresses tolerance of S. suis serotype 2 such as survive thermal, oxidative and acid stresses. Quantification of expression levels of known S. suis serotype 2 SC21 virulence genes by real-time polymerase chain reaction in vitro revealed that trigger factor influences the expression of epf, cps, adh, rpob, fbps, hyl, sly, mrp and hrcA virulence-associated genes. ΔTig was shown to be attenuated in a LD50 assay and bacteriology, indicating that trigger factor plays an important part in the pathogenesis and stress tolerance of. S. suis serotype 2 infection. Mutant ΔTig was 100% defective in virulence in CD1 mice at up to 107 CFU, and provided 100% protection when challenged with 107 CFU of the SC21 strain.
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Affiliation(s)
- Tao Wu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan 430023, PR China
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29
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Hoffmann A, Bukau B, Kramer G. Structure and function of the molecular chaperone Trigger Factor. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:650-61. [PMID: 20132842 DOI: 10.1016/j.bbamcr.2010.01.017] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 01/22/2010] [Indexed: 01/16/2023]
Abstract
Newly synthesized proteins often require the assistance of molecular chaperones to efficiently fold into functional three-dimensional structures. At first, ribosome-associated chaperones guide the initial folding steps and protect growing polypeptide chains from misfolding and aggregation. After that folding into the native structure may occur spontaneously or require support by additional chaperones which do not bind to the ribosome such as DnaK and GroEL. Here we review the current knowledge on the best-characterized ribosome-associated chaperone at present, the Escherichia coli Trigger Factor. We describe recent progress on structural and dynamic aspects of Trigger Factor's interactions with the ribosome and substrates and discuss how these interactions affect co-translational protein folding. In addition, we discuss the newly proposed ribosome-independent function of Trigger Factor as assembly factor of multi-subunit protein complexes. Finally, we cover the functional cooperation between Trigger Factor, DnaK and GroEL in folding of cytosolic proteins and the interplay between Trigger Factor and other ribosome-associated factors acting in enzymatic processing and translocation of nascent polypeptide chains.
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Affiliation(s)
- Anja Hoffmann
- Zentrum für Molekulare Biologie der Universität Heidelberg, Heidelberg, Germany
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30
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The metal homeostasis protein, Lsp, of Streptococcus pyogenes is necessary for acquisition of zinc and virulence. Infect Immun 2009; 77:2840-8. [PMID: 19398546 DOI: 10.1128/iai.01299-08] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
"Cluster 9" family lipoproteins function as ligand-binding subunits of ABC-type transporters in maintaining transition metal homeostasis and have been implicated in the virulence of several bacteria. While these proteins share high similarity, the specific metal that they recognize and whether their role in virulence directly involves metal homeostasis cannot be reliably predicted. We examined the cluster 9 protein Lsp of Streptococcus pyogenes and found that specific deletion of lsp produced mutants highly attenuated in a murine model of soft tissue infection. Under standard in vitro conditions, growth of the Lsp(-) mutant was indistinguishable from that of the wild type, but growth was defective under zinc-limited conditions. The growth defect could be complemented by plasmids expressing wild-type Lsp but not Lsp engineered to lack its putative lipidation residue. Furthermore, Zn(2+) but not Mn(2+) rescued Lsp(-) growth, implicating Zn(2+) as the physiological ligand for Lsp. Mutation of residues in the putative Zn(2+)-binding pocket generated variants both hypo- and hyper-resistant to zinc starvation, and both mutant classes displayed attenuated virulence. Together, these data suggest that Lsp is a ligand-binding component of an ABC-type zinc permease and that perturbation of zinc homeostasis inhibits the ability of S. pyogenes to cause disease in a zinc-limited host milieu.
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31
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First Streptococcus pyogenes signature-tagged mutagenesis screen identifies novel virulence determinants. Infect Immun 2009; 77:1854-65. [PMID: 19223485 DOI: 10.1128/iai.01306-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virulence of bacterial pathogens is a complex process that requires the dynamic expression of many genes for the pathogens to invade and circumvent host defenses, as well as to proliferate in vivo. In this study, we employed a large-scale screen, signature-tagged mutagenesis (STM), to identify Streptococcus pyogenes virulence genes important for pathogenesis within the host. Approximately 1,200 STM mutants were created and screened using the zebrafish infectious disease model. The transposon insertion site was identified for 29 of the 150 mutants that were considered attenuated for virulence. Previously reported streptococcal virulence genes, such as mga, hasA, amrA, smeZ, and two genes in the sil locus, were identified, confirming the utility of the model for revealing genes important for virulence. Multiple genes not previously implicated in virulence were also identified, including genes encoding putative transporters, hypothetical cytosolic proteins, and macrolide efflux pumps. The STM mutant strains display various levels of attenuation, and multiple separate insertions were identified in either the same gene or the same locus, suggesting that these factors are important for this type of acute, invasive infection. We further examined two such genes, silB and silC of a putative quorum-sensing regulon, and determined that they are significant virulence factors in our model of necrotizing fasciitis. sil locus promoter expression was examined under various in vitro conditions, as well as in zebrafish tissues, and was found to be differentially induced. This study was a unique investigation of S. pyogenes factors required for successful invasive infection.
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32
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Hollands A, Aziz RK, Kansal R, Kotb M, Nizet V, Walker MJ. A naturally occurring mutation in ropB suppresses SpeB expression and reduces M1T1 group A streptococcal systemic virulence. PLoS One 2008; 3:e4102. [PMID: 19116661 PMCID: PMC2605554 DOI: 10.1371/journal.pone.0004102] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 11/21/2008] [Indexed: 11/18/2022] Open
Abstract
Epidemiological studies of group A streptococcus (GAS) have noted an inverse relationship between SpeB expression and invasive disease. However, the role of SpeB in the course of infection is still unclear. In this study we utilize a SpeB-negative M1T1 clinical isolate, 5628, with a naturally occurring mutation in the gene encoding the regulator RopB, to elucidate the role of RopB and SpeB in systemic virulence. Allelic exchange mutagenesis was used to replace the mutated ropB allele in 5628 with the intact allele from the well characterized isolate 5448. The inverse allelic exchange was also performed to replace the intact ropB in 5448 with the mutated allele from 5628. An intact ropB was found to be essential for SpeB expression. While the ropB mutation was shown to have no effect on hemolysis of RBC's, extracellular DNase activity or survival in the presence of neutrophils, strains with the mutated ropB allele were less virulent in murine systemic models of infection. An isogenic SpeB knockout strain containing an intact RopB showed similarly reduced virulence. Microarray analysis found genes of the SpeB operon to be the primary target of RopB regulation. These data show that an intact RopB and efficient SpeB production are necessary for systemic infection with GAS.
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Affiliation(s)
- Andrew Hollands
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
- The Department of Molecular Genetics, Biochemistry and Microbiology, The University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States of America
| | - Ramy K. Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Rita Kansal
- The VA Hospital, Memphis, Tennessee, United States of America
| | - Malak Kotb
- The VA Hospital, Memphis, Tennessee, United States of America
- The Department of Molecular Genetics, Biochemistry and Microbiology, The University of Cincinnati, College of Medicine, Cincinnati, Ohio, United States of America
| | - Victor Nizet
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States of America
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Mark J. Walker
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
- * E-mail:
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Thapa A, Shahnawaz M, Karki P, Raj Dahal G, Golam Sharoar M, Yub Shin S, Sup Lee J, Cho B, Park IS. Purification of inclusion body—forming peptides and proteins in soluble form by fusion to Escherichia coli thermostable proteins. Biotechniques 2008; 44:787-96. [DOI: 10.2144/000112728] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Proteins and peptides expressed in the prokaryotic system often form inclusion bodies. Solubilization and refolding procedures can be used for their recovery, but this process remains difficult. One strategy for improving the solubility of a protein of interest is to fuse it to a highly soluble protein. To select a suitable fusion partner capable of solubilizing the aggregation-prone (inclusion body–forming) proteins and peptides, Escherichia coli thermostable proteins were identified and tested. Among them, trigger factor (TF) protein was selected because of its high expression and stability. Using an expression system based on fusion to TF, selected proteins and peptides that otherwise form inclusion bodies were expressed in soluble state and were purified like other soluble proteins. This system provides a convenient method for production of aggregation-prone proteins and peptides.
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34
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Requirements for surface expression and function of adhesin P1 from Streptococcus mutans. Infect Immun 2008; 76:2456-68. [PMID: 18362133 DOI: 10.1128/iai.01315-07] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this report, we define requirements for the successful translocation and functional maturation of the adhesin P1 of Streptococcus mutans. Conformational epitopes recognized by anti-P1 monoclonal antibodies (MAbs) were further characterized, thus facilitating the use of particular MAbs as tools to monitor the locations of various forms of the protein. We show that correct localization of P1 is dependent on structural features of the molecule itself, including a requisite A region-P region intramolecular interaction that occurs within the cell prior to secretion. P1 also was shown to be affected by several members of the protein-folding-secretion-turnover apparatus. It does not achieve a fully functional form in the absence of the trigger factor PPIase homolog RopA, and its translocation is delayed when DnaK levels are limited. In addition, dnaK message levels are differentially altered in the presence of P1 lacking the alanine-rich compared to the proline-rich repeat domains. Lastly, nonsecreted P1 lacking the P region accumulates within the cell in the absence of htrA, implying an intracellular HtrA protease function in the degradation and turnover of this particular internal-deletion polypeptide. However, the opposite effect is seen for full-length P1, suggesting a sensing mechanism and substrate-dependent alteration in HtrA's function and effect that is consistent with its known ability to switch between chaperone and protease, depending on environmental perturbations.
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35
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Cole JN, Aquilina JA, Hains PG, Henningham A, Sriprakash KS, Caparon MG, Nizet V, Kotb M, Cordwell SJ, Djordjevic SP, Walker MJ. Role of group A Streptococcus HtrA in the maturation of SpeB protease. Proteomics 2008; 7:4488-98. [PMID: 18072207 DOI: 10.1002/pmic.200700626] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The serine protease high-temperature requirement A (HtrA) (DegP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExPortal secretory microdomain and is reportedly essential for the maturation of cysteine protease streptococcal pyrogenic exotoxin B (SpeB). Here, we utilize HSC5 (M5 serotype) and the in-frame isogenic mutant HSC5DeltahtrA to determine whether HtrA contributes to the maturation of other GAS virulence determinants. Mutanolysin cell wall extracts and secreted proteins were arrayed by 2-DE and identified by MALDI-TOF PMF analysis. HSC5DeltahtrA had elevated levels of cell wall-associated M protein, whilst the supernatant had higher concentrations of M protein fragments and a reduced amount of mature SpeB protease, compared to wild-type (WT). Western blot analysis and protease assays revealed a delay in the maturation of SpeB in the HSC5DeltahtrA supernatant. HtrA was unable to directly process SpeB zymogen (proSpeB) to the active form in vitro. We therefore conclude that HtrA plays an indirect role in the maturation of cysteine protease SpeB.
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Affiliation(s)
- Jason N Cole
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
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36
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Severin A, Nickbarg E, Wooters J, Quazi SA, Matsuka YV, Murphy E, Moutsatsos IK, Zagursky RJ, Olmsted SB. Proteomic analysis and identification of Streptococcus pyogenes surface-associated proteins. J Bacteriol 2007; 189:1514-22. [PMID: 17142387 PMCID: PMC1855729 DOI: 10.1128/jb.01132-06] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Accepted: 11/21/2006] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pyogenes is a gram-positive human pathogen that causes a wide spectrum of disease, placing a significant burden on public health. Bacterial surface-associated proteins play crucial roles in host-pathogen interactions and pathogenesis and are important targets for the immune system. The identification of these proteins for vaccine development is an important goal of bacterial proteomics. Here we describe a method of proteolytic digestion of surface-exposed proteins to identify surface antigens of S. pyogenes. Peptides generated by trypsin digestion were analyzed by multidimensional tandem mass spectrometry. This approach allowed the identification of 79 proteins on the bacterial surface, including 14 proteins containing cell wall-anchoring motifs, 12 lipoproteins, 9 secreted proteins, 22 membrane-associated proteins, 1 bacteriophage-associated protein, and 21 proteins commonly identified as cytoplasmic. Thirty-three of these proteins have not been previously identified as cell surface associated in S. pyogenes. Several proteins were expressed in Escherichia coli, and the purified proteins were used to generate specific mouse antisera for use in a whole-cell enzyme-linked immunosorbent assay. The immunoreactivity of specific antisera to some of these antigens confirmed their surface localization. The data reported here will provide guidance in the development of a novel vaccine to prevent infections caused by S. pyogenes.
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37
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Rosch JW, Hsu FF, Caparon MG. Anionic lipids enriched at the ExPortal of Streptococcus pyogenes. J Bacteriol 2006; 189:801-6. [PMID: 17142392 PMCID: PMC1797331 DOI: 10.1128/jb.01549-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The ExPortal of Streptococcus pyogenes is a membrane microdomain dedicated to the secretion and folding of proteins. We investigated the lipid composition of the ExPortal by examining the distribution of anionic membrane phospholipids. Staining with 10-N-nonyl-acridine orange revealed a single microdomain enriched with an anionic phospholipid whose staining characteristics and behavior in a cardiolipin-deficient mutant were characteristic of phosphatidylglycerol. Furthermore, the location of the microdomain corresponded to the site of active protein secretion at the ExPortal. These results indicate that the ExPortal is an asymmetric lipid microdomain, whose enriched content of anionic phospholipids may play an important role in ExPortal organization and protein trafficking.
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Affiliation(s)
- Jason W Rosch
- Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, 660 S. Euclid Ave. no. 8230, St. Louis, MO 63110-1093, USA
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38
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Bigot A, Botton E, Dubail I, Charbit A. A homolog of Bacillus subtilis trigger factor in Listeria monocytogenes is involved in stress tolerance and bacterial virulence. Appl Environ Microbiol 2006; 72:6623-31. [PMID: 17021213 PMCID: PMC1610291 DOI: 10.1128/aem.00624-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Molecular chaperones play an essential role in the folding of nascent chain polypeptides, as well as in the refolding and degradation of misfolded or aggregated proteins. They also assist in protein translocation and participate in stress functions. We identified a gene, designated tig, encoding a protein homologous to trigger factor (TF), a cytosolic ribosome-associated chaperone, in the genome of Listeria monocytogenes. We constructed a chromosomal Delta tig deletion and evaluated the impact of the mutation on bacterial growth in broth under various stress conditions and on pathogenesis. The Delta tig deletion did not affect cell viability but impaired survival in the presence of heat and ethanol stresses. We also identified the ffh gene, encoding a protein homologous to the SRP54 eukaryotic component of the signal recognition particle. However, a Delta ffh deletion was not tolerated, suggesting that Ffh is essential, as it is in Bacillus subtilis and Escherichia coli. Thus, although dispensable for growth, TF is involved in the stress response of L. monocytogenes. The Delta tig mutant showed no or very modest intracellular survival defects in eukaryotic cells. However, in vivo it showed a reduced capacity to persist in the spleens and livers of infected mice, revealing that TF has a role in the pathogenicity of L. monocytogenes.
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Affiliation(s)
- Armelle Bigot
- INSERM U-570, CHU Necker-Enfants Malades, 156, rue de Vaugirard, 75730 Paris Cedex 15, France
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39
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Hasona A, Zuobi-Hasona K, Crowley PJ, Abranches J, Ruelf MA, Bleiweis AS, Brady LJ. Membrane composition changes and physiological adaptation by Streptococcus mutans signal recognition particle pathway mutants. J Bacteriol 2006; 189:1219-30. [PMID: 17085548 PMCID: PMC1797365 DOI: 10.1128/jb.01146-06] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Previously, we presented evidence that the oral cariogenic species Streptococcus mutans remains viable but physiologically impaired and sensitive to environmental stress when genes encoding the minimal conserved bacterial signal recognition particle (SRP) elements are inactivated. Two-dimensional gel electrophoresis of isolated membrane fractions from strain UA159 and three mutants (Deltaffh, DeltascRNA, and DeltaftsY) grown at pH 7.0 or pH 5.0 allowed us to obtain insight into the adaptation process and the identities of potential SRP substrates. Mutant membrane preparations contained increased amounts of the chaperones DnaK and GroES and ClpP protease but decreased amounts of transcription- and translation-related proteins, the beta subunit of ATPase, HPr, and several metabolic and glycolytic enzymes. Therefore, the acid sensitivity of SRP mutants might be caused in part by diminished ATPase activity, as well as the absence of an efficient mechanism for supplying ATP quickly at the site of proton elimination. Decreased amounts of LuxS were also observed in all mutant membranes. To further define physiological changes that occur upon disruption of the SRP pathway, we studied global gene expression in S. mutans UA159 (parent strain) and AH333 (Deltaffh mutant) using microarray analysis. Transcriptome analysis revealed up-regulation of 81 genes, including genes encoding chaperones, proteases, cell envelope biosynthetic enzymes, and DNA repair and replication enzymes, and down-regulation of 35 genes, including genes concerned with competence, ribosomal proteins, and enzymes involved in amino acid and protein biosynthesis. Quantitative real-time reverse transcription-PCR analysis of eight selected genes confirmed the microarray data. Consistent with a demonstrated defect in competence and the suggested impairment of LuxS-dependent quorum sensing, biofilm formation was significantly decreased in each SRP mutant.
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Affiliation(s)
- Adnan Hasona
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA.
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40
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Abstract
Many proteins have developed the potential to sequester a client polypeptide chain in its various folding states as a specific intermolecular ligand and, thus, exhibit the properties of a holding chaperone. The resulting complexes can be of a diverse nature in terms of structure and reaction dynamics and are characterized on the basis of various microscopic properties including formation and decay of encounter and Michaelis complexes as well as reactant and product stability. Interpretation of the functional consequences of complex formation in the cell generally tends to be rather complicated, with notable exceptions including complexes formed during the reaction pathways of proteases, protein kinases and protein phosphatases. Peptide bond cis/trans isomerases take up an intermediate position among the poly(oligo)peptide binding proteins because, although the relationship between chain sequestration and catalysis of isomerization can easily be delineated in vitro, it is sometimes difficult to resolve in the cell. Time-resolved studies on interactions involving peptide bond cis/trans isomerases have led to the establishment of generally applicable methods for studying protein-poly(oligo)peptide interactions that are capable of identifying new types of biocatalysis.
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Affiliation(s)
- Gunter Fischer
- Max-Planck Research Unit for Enzymology of Protein Folding, Max Planck Society, Weinbergweg 22, D-06120 Halle/Saale, Germany.
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41
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Henderson B, Allan E, Coates ARM. Stress wars: the direct role of host and bacterial molecular chaperones in bacterial infection. Infect Immun 2006; 74:3693-706. [PMID: 16790742 PMCID: PMC1489680 DOI: 10.1128/iai.01882-05] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Brian Henderson
- Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, 256 Gray's Inn Road, London WC1X, United Kingdom.
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42
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Meehl MA, Pinkner JS, Anderson PJ, Hultgren SJ, Caparon MG. A novel endogenous inhibitor of the secreted streptococcal NAD-glycohydrolase. PLoS Pathog 2005; 1:e35. [PMID: 16333395 PMCID: PMC1298937 DOI: 10.1371/journal.ppat.0010035] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 08/24/2005] [Indexed: 02/07/2023] Open
Abstract
The Streptococcus pyogenes NAD-glycohydrolase (SPN) is a toxic enzyme that is introduced into infected host cells by the cytolysin-mediated translocation pathway. However, how S. pyogenes protects itself from the self-toxicity of SPN had been unknown. In this report, we describe immunity factor for SPN (IFS), a novel endogenous inhibitor that is essential for SPN expression. A small protein of 161 amino acids, IFS is localized in the bacterial cytoplasmic compartment. IFS forms a stable complex with SPN at a 1:1 molar ratio and inhibits SPN's NAD-glycohydrolase activity by acting as a competitive inhibitor of its β-NAD+ substrate. Mutational studies revealed that the gene for IFS is essential for viability in those S. pyogenes strains that express an NAD-glycohydrolase activity. However, numerous strains contain a truncated allele of ifs that is linked to an NAD-glycohydrolase−deficient variant allele of spn. Of practical concern, IFS allowed the normally toxic SPN to be produced in the heterologous host Escherichia coli to facilitate its purification. To our knowledge, IFS is the first molecularly characterized endogenous inhibitor of a bacterial β-NAD+−consuming toxin and may contribute protective functions in the streptococci to afford SPN-mediated pathogenesis. The gram-positive bacterium Streptococcus pyogenes is a human pathogen that causes a wide range of infections from pharyngitis (“strep throat”) to invasive necrotizing fasciitis (“flesh-eating disease”). While strep throat responds to antibiotic therapy, more invasive infections caused by S. pyogenes often require surgical intervention. It is currently unknown exactly how the bacteria can switch between the different types of infection, but one possibility is via a mechanism by which the bacterium injects a bacterial protein toxin (S. pyogenes NAD-glycohydrolase [SPN]) into human skin cells, causing their death. In this study, the authors have shown that the injected toxin also has the ability to affect the bacteria. A second protein neutralizes SPN to ensure the bacteria are immune to its toxic effects. Consequently, S. pyogenes has developed a valuable weapon in its arsenal to promote its survival by ensuring the safe production of SPN, through its own protection by immunity factor for SPN, enabling the delivery of active SPN into human cells. The process reported in this paper may ultimately help create therapeutic inhibitors of SPN and possibly other SPN-like toxins implicated in microbial disease progression.
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Affiliation(s)
- Michael A Meehl
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jerome S Pinkner
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Patricia J Anderson
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Scott J Hultgren
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael G Caparon
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * To whom correspondence should be addressed. E-mail:
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43
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Bobek J, Halada P, Angelis J, Vohradský J, Mikulík K. Activation and expression of proteins during synchronous germination of aerial spores of Streptomyces granaticolor. Proteomics 2005; 4:3864-80. [PMID: 15378695 DOI: 10.1002/pmic.200400818] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Synchronously germinating aerial spores of Streptomyces granaticolor were used to study protein activation and expression during the transition from dormant to metabolically active vegetative forms. The first phase of protein activation is associated with the solubility of proteins. Three major chaperones, DnaK, Trigger factor, and GroEL, were identified in spores. Enhancement in rate of protein synthesis during germination was accompanied by the association of TF and DnaK with ribosomes. During germination, the chaperones TF, GroEL, and DnaK undergo reversible phosphorylation. GroEL was phosphorylated on both Ser and Thr, whereas phosphorylation of DnaK and TF was detected on Thr only. A proteomic approach was used to gain more information on protein expression during germination on two types of media differing in the ability of cells to produce antibiotic granaticin. To obtain an overview of the metabolic activity of germinating spores, glycolytic enzymes, enzymes of citric acid cycle, metabolism of amino acids and nucleic acids, and components of the protein synthesis system were identified and analyzed using the proteomic database. The results were deposited on the SWICZ proteomic server and are accessible on http://proteom.biomed.cas.cz.
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Affiliation(s)
- Jan Bobek
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
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44
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Wei L, Pandiripally V, Gregory E, Clymer M, Cue D. Impact of the SpeB protease on binding of the complement regulatory proteins factor H and factor H-like protein 1 by Streptococcus pyogenes. Infect Immun 2005; 73:2040-50. [PMID: 15784545 PMCID: PMC1087456 DOI: 10.1128/iai.73.4.2040-2050.2005] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial pathogens often exploit human complement regulatory proteins such as factor H (FH) and factor H-like protein 1 (FHL-1) for immune evasion. Fba is an FH and FHL-1 binding protein expressed on the surface of the human pathogenic bacterium Streptococcus pyogenes, a common agent of pharyngeal, skin, and soft-tissue infections. Fba has been shown to contribute to phagocytosis resistance, intracellular invasion, and virulence in mice. Here, we look at the role of Fba in recruitment of FH and FHL-1 by five serotype M1 isolates of streptococci. Inactivation of fba greatly inhibited binding of FH and FHL-1 by all isolates, indicating that Fba is a major FH and FHL-1 binding factor of serotype M1 streptococci. For three isolates, FH binding was significantly reduced in stationary-phase cultures and correlated with high levels of protease activity and SpeB (an extracellular cysteine protease) protein in culture supernatants. Analysis of a speB mutant confirmed that SpeB accounts for the loss of Fba from the cell surface, suggesting that the protease may modulate FH and FHL-1 recruitment during infection. Comparisons of fba DNA sequences revealed that the FH and FHL-1 binding site in Fba is conserved among the M1 isolates. Although the ligand binding site is not strictly conserved in Fba from a serotype M49 isolate, the M49 Fba protein was found to bind both FH and FHL-1. Collectively, these data indicate that binding of FH and FHL-1 is a conserved function of Fba while modulation of Fba function by SpeB is variable.
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Affiliation(s)
- Lin Wei
- Department of Microbiology, Molecular Genetics and Immunology, Mail Stop 3029, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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45
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Zimmerlein B, Park HS, Li S, Podbielski A, Cleary PP. The M protein is dispensable for maturation of streptococcal cysteine protease SpeB. Infect Immun 2005; 73:859-64. [PMID: 15664926 PMCID: PMC546975 DOI: 10.1128/iai.73.2.859-864.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The streptococcal pyrogenic exotoxin B (SpeB) is an important virulence factor of group A streptococci (GAS) with cysteine protease activity. Maturation of SpeB to a proteolytically active form was suggested to be dependent on cell-wall-anchored M1 protein, the major surface protein of GAS (M. Collin and A. Olsen, Mol. Microbiol. 36:1306-1318, 2000). Collin and Olsen showed that mutant GAS strains expressing truncated M protein secrete a conformationally different form of unprocessed SpeB with no proteolytic activity. Alternatively, we hypothesized that a truncated M protein may interfere with processing of this secreted protease, and therefore we tested cysteine protease activity in genetically defined mutant strains that express either no M protein or membrane-anchored M protein with an in-frame deletion of the AB repeat region. Measurements of SpeB activity by cleavage of a substrate n-benzoyl-Pro-Phe-Arg-p-nitroanilide hydrochloride showed that the proteolytic activities in culture supernatants of both mutants were similar to those from the wild-type strain. In addition, Western blot analysis of culture supernatants showed that SpeB expression and processing to a mature form was unaffected by either deletion mutation. Therefore, we conclude that M protein is not required for maturation of the streptococcal cysteine protease SpeB.
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Affiliation(s)
- Björn Zimmerlein
- Department of Microbiology, University of Minnesota Medical School, 1460 Mayo Bldg., MMC196, 420 Delaware Street SE, Minneapolis, MN 55455, USA
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46
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Mangold M, Siller M, Roppenser B, Vlaminckx BJM, Penfound TA, Klein R, Novak R, Novick RP, Charpentier E. Synthesis of group A streptococcal virulence factors is controlled by a regulatory RNA molecule. Mol Microbiol 2005; 53:1515-27. [PMID: 15387826 DOI: 10.1111/j.1365-2958.2004.04222.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The capacity of pathogens to cause disease depends strictly on the regulated expression of their virulence factors. In this study, we demonstrate that the untranslated mRNA of the recently described streptococcal pleiotropic effect locus (pel), which incidentally contains sagA, the structural gene for streptolysin S, is an effector of virulence factor expression in group A beta-haemolytic streptococci (GAS). Our data suggest that the regulation by pel RNA occurs at both transcriptional (e.g. emm, sic, nga) and post-transcriptional (e.g. SpeB) levels. We could exclude the possibility that the pel phenotype was linked to a polar effect on downstream genes (sagB-I). Remarkably, the RNA effector is regulated in a growth phase-dependent fashion and we provide evidence that pel RNA expression is induced by conditioned media.
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Affiliation(s)
- Monika Mangold
- Max F. Perutz Laboratories, University Departments at the Vienna Biocenter, Department of Microbiology and Genetics, University of Vienna, Dr Bohrgasse 9/4, Vienna A-1030, Austria
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47
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Wen ZT, Suntharaligham P, Cvitkovitch DG, Burne RA. Trigger factor in Streptococcus mutans is involved in stress tolerance, competence development, and biofilm formation. Infect Immun 2005; 73:219-25. [PMID: 15618157 PMCID: PMC538946 DOI: 10.1128/iai.73.1.219-225.2005] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 09/01/2004] [Accepted: 10/01/2004] [Indexed: 11/20/2022] Open
Abstract
Trigger factor is a ribosome-associated peptidyl-prolyl cis/trans isomerase that is highly conserved in most bacteria. A gene, designated ropA, encoding an apparent trigger factor homologue, was identified in Streptococcus mutans, the primary etiological agent of human dental caries. Inactivation of ropA had no major impact on growth rate in planktonic cultures under the conditions tested, although the RopA-deficient mutant formed long chains in broth. Deficiency of RopA decreased tolerance to acid killing and to oxidative stresses induced by hydrogen peroxide and paraquat, and it reduced transformation efficiency about 200-fold. Addition of synthetic competence-stimulating peptide to the culture medium enhanced transformability of both the mutant and wild-type strains, although the ropA strain did not attain levels of competence observed for the parent. Loss of RopA decreased the capacity of S. mutans to form biofilms by over 80% when cultivated in glucose, but it increased biofilm formation by over 50% when sucrose was provided as the carbohydrate source. Western blot analysis revealed that the expression of glucosyltransferases B and D was lower in the RopA-deficient mutant. These results suggest that RopA is a key regulator of acid and oxidative stress tolerance, genetic competence, and biofilm formation, all critical virulence properties of S. mutans.
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Affiliation(s)
- Zezhang T Wen
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL 32610, USA
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48
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Minion FC, Lefkowitz EJ, Madsen ML, Cleary BJ, Swartzell SM, Mahairas GG. The genome sequence of Mycoplasma hyopneumoniae strain 232, the agent of swine mycoplasmosis. J Bacteriol 2004; 186:7123-33. [PMID: 15489423 PMCID: PMC523201 DOI: 10.1128/jb.186.21.7123-7133.2004] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present the complete genome sequence of Mycoplasma hyopneumoniae, an important member of the porcine respiratory disease complex. The genome is composed of 892,758 bp and has an average G+C content of 28.6 mol%. There are 692 predicted protein coding sequences, the average protein size is 388 amino acids, and the mean coding density is 91%. Functions have been assigned to 304 (44%) of the predicted protein coding sequences, while 261 (38%) of the proteins are conserved hypothetical proteins and 127 (18%) are unique hypothetical proteins. There is a single 16S-23S rRNA operon, and there are 30 tRNA coding sequences. The cilium adhesin gene has six paralogs in the genome, only one of which contains the cilium binding site. The companion gene, P102, also has six paralogs. Gene families constitute 26.3% of the total coding sequences, and the largest family is the 34-member ABC transporter family. Protein secretion occurs through a truncated pathway consisting of SecA, SecY, SecD, PrsA, DnaK, Tig, and LepA. Some highly conserved eubacterial proteins, such as GroEL and GroES, are notably absent. The DnaK-DnaJ-GrpR complex is intact, providing the only control over protein folding. There are several proteases that might serve as virulence factors, and there are 53 coding sequences with prokaryotic lipoprotein lipid attachment sites. Unlike other mycoplasmas, M. hyopneumoniae contains few genes with tandem repeat sequences that could be involved in phase switching or antigenic variation. Thus, it is not clear how M. hyopneumoniae evades the immune response and establishes a chronic infection.
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Affiliation(s)
- F Chris Minion
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA 50011, USA.
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49
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Hancock LE, Perego M. The Enterococcus faecalis fsr two-component system controls biofilm development through production of gelatinase. J Bacteriol 2004; 186:5629-39. [PMID: 15317767 PMCID: PMC516840 DOI: 10.1128/jb.186.17.5629-5639.2004] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial growth as a biofilm on solid surfaces is strongly associated with the development of human infections. Biofilms on native heart valves (infective endocarditis) is a life-threatening disease as a consequence of bacterial resistance to antimicrobials in such a state. Enterococci have emerged as a cause of endocarditis and nosocomial infections despite being normal commensals of the gastrointestinal and female genital tracts. We examined the role of two-component signal transduction systems in biofilm formation by the Enterococcus faecalis V583 clinical isolate and identified the fsr regulatory locus as the sole two-component system affecting this unique mode of bacterial growth. Insertion mutations in the fsr operon affected biofilm formation on two distinct abiotic surfaces. Inactivation of the fsr-controlled gene gelE encoding the zinc-metalloprotease gelatinase was found to prevent biofilm formation, suggesting that this enzyme may present a unique target for therapeutic intervention in enterococcal endocarditis.
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Affiliation(s)
- Lynn E Hancock
- Division of Cellular Biology, Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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50
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Ludlam AV, Moore BA, Xu Z. The crystal structure of ribosomal chaperone trigger factor from Vibrio cholerae. Proc Natl Acad Sci U S A 2004; 101:13436-41. [PMID: 15353602 PMCID: PMC518775 DOI: 10.1073/pnas.0405868101] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Trigger factor is a molecular chaperone that is present in all species of eubacteria. It binds to the ribosomal 50S subunit near the translation exit tunnel and is thought to be the first protein to interact with nascent polypeptides emerging from the ribosome. The chaperone has a peptidyl-prolyl cis-trans isomerase (PPIase) activity that catalyzes the rate-limiting proline isomerization in the protein-folding process. We have determined the crystal structure of nearly full-length trigger factor from Vibrio cholerae by x-ray crystallography at 2.5-A resolution. The structure is composed of two trigger-factor molecules related by a noncrystallographic two-fold symmetry axis. The monomer has an elongated shape and is folded into three domains: an N-terminal domain I that binds to the ribosome, a central domain II that contains PPIase activity, and a C-terminal domain III. The active site of the PPIase domain is occupied by a loop from domain III, suggesting that the PPIase activity of the protein could be regulated. The dimer interface is formed between domains I and III and contains residues of mixed properties. Further implications about dimerization, ribosome binding, and other functions of trigger factor are discussed.
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Affiliation(s)
- Anthony V Ludlam
- Department of Biological Chemistry, Medical School and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
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