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Irfan M, Solbiati J, Duran-Pinedo A, Rocha FG, Gibson FC, Frias-Lopez J. A Porphyromonas gingivalis hypothetical protein controlled by the type I-C CRISPR-Cas system is a novel adhesin important in virulence. mSystems 2024; 9:e0123123. [PMID: 38323815 PMCID: PMC10949514 DOI: 10.1128/msystems.01231-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 12/26/2023] [Indexed: 02/08/2024] Open
Abstract
The ability of many human pathogens to infect requires their ability to adhere to the host surfaces as a first step in the process. Porphyromonas gingivalis, a keystone oral pathogen, uses adhesins to adhere to the surface of the gingival epithelium and other members of the oral microbiome. In a previous study, we identified several proteins potentially linked to virulence whose mRNA levels are regulated by CRISPR-Cas type I-C. Among those, PGN_1547 was highly upregulated in the CRISPR-Cas 3 mutant. PGN_1547 is annotated as a hypothetical protein. Employing homology searching, our data support that PGN_1547 resembles an auto-transporter adhesin of P. gingivalis based on containing the DUF2807 domain. To begin to characterize the function of PGN_1547, we found that a deletion mutant displayed a significant decrease in virulence using a Galleria mellonela model. Furthermore, this mutant was significantly impaired in forming biofilms and attaching to the macrophage-like cell THP-1. Luminex revealed that the PGN_1547 mutant elicited a less robust cytokine and chemokine response from THP-1 cells, and TLR2 predominantly sensed that recombinant PGN_1547. Taken together, these findings broaden our understanding of the toolbox of virulence factors possessed by P. gingivalis. Importantly, PGN_1547, a hypothetical protein, has homologs in another member of the order Bacteroidales whose function is unknown, and our results could shed light on the role of this family of proteins as auto-transport adhesins in this phylogenetic group.IMPORTANCEPeriodontal diseases are among humans' most common infections, and besides their effect on the oral cavity, they have been associated with systemic inflammatory conditions. Among members of the oral microbiome implicated in the development of periodontitis, Porphyromonas gingivalis is considered a keystone pathogen. We have identified a new adhesin that acts as a virulence factor, PGN_1547, which contains the DUF2807 domain, which belongs to the putative auto-transporter adhesin, head GIN domain family. Deletion of this gene lowers the virulence of P. gingivalis and impacts the ability of P. gingivalis to form biofilm and attach to host cells. Furthermore, the broad distribution of these receptors in the order Bacteroidales suggests their importance in colonization by this important group of organisms.
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Affiliation(s)
- Muhammad Irfan
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Jose Solbiati
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Ana Duran-Pinedo
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Fernanda Godoy Rocha
- Department of Periodontology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Frank C. Gibson
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Jorge Frias-Lopez
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
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2
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Meuskens I, Kristiansen PE, Bardiaux B, Koynarev VR, Hatlem D, Prydz K, Lund R, Izadi-Pruneyre N, Linke D. A poly-proline II helix in YadA from Yersinia enterocolitica serotype O:9 facilitates heparin binding through electrostatic interactions. FEBS J 2024; 291:761-777. [PMID: 37953437 DOI: 10.1111/febs.17001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/25/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023]
Abstract
Poly-proline II helices are secondary structure motifs frequently found in ligand-binding sites. They exhibit increased flexibility and solvent exposure compared to the strongly hydrogen-bonded α-helices or β-strands and can therefore easily be misinterpreted as completely unstructured regions with an extremely high rotational freedom. Here, we show that the adhesin YadA of Yersinia enterocolitica serotype O:9 contains a poly-proline II helix interaction motif in the N-terminal region. The motif is involved in the interaction of YadAO:9 with heparin, a host glycosaminoglycan. We show that the basic residues within the N-terminal motif of YadA are required for electrostatic interactions with the sulfate groups of heparin. Biophysical methods including CD spectroscopy, solution-state NMR and SAXS all independently support the presence of a poly-proline helix allowing YadAO:9 binding to the rigid heparin. Lastly, we show that host cells deficient in sulfation of heparin and heparan sulfate are not targeted by YadAO:9 -mediated adhesion. We speculate that the YadAO:9 -heparin interaction plays an important and highly strain-specific role in the pathogenicity of Yersinia enterocolitica serotype O:9.
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Affiliation(s)
- Ina Meuskens
- Department of Biosciences, University of Oslo, Norway
| | | | - Benjamin Bardiaux
- Structural Bioinformatics Unit, CNRS UMR3528, Institut Pasteur, Université de Paris-Cité, France
| | | | - Daniel Hatlem
- Department of Biosciences, University of Oslo, Norway
| | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Norway
| | - Nadia Izadi-Pruneyre
- Bacterial Transmembrane Systems Unit, CNRS UMR3528, Institut Pasteur, Université de Paris-Cité, France
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Norway
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3
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Mintz KP, Danforth DR, Ruiz T. The Trimeric Autotransporter Adhesin EmaA and Infective Endocarditis. Pathogens 2024; 13:99. [PMID: 38392837 PMCID: PMC10892112 DOI: 10.3390/pathogens13020099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
Infective endocarditis (IE), a disease of the endocardial surface of the heart, is usually of bacterial origin and disproportionally affects individuals with underlying structural heart disease. Although IE is typically associated with Gram-positive bacteria, a minority of cases are caused by a group of Gram-negative species referred to as the HACEK group. These species, classically associated with the oral cavity, consist of bacteria from the genera Haemophilus (excluding Haemophilus influenzae), Aggregatibacter, Cardiobacterium, Eikenella, and Kingella. Aggregatibacter actinomycetemcomitans, a bacterium of the Pasteurellaceae family, is classically associated with Aggressive Periodontitis and is also concomitant with the chronic form of the disease. Bacterial colonization of the oral cavity serves as a reservoir for infection at distal body sites via hematological spreading. A. actinomycetemcomitans adheres to and causes disease at multiple physiologic niches using a diverse array of bacterial cell surface structures, which include both fimbrial and nonfimbrial adhesins. The nonfimbrial adhesin EmaA (extracellular matrix binding protein adhesin A), which displays sequence heterogeneity dependent on the serotype of the bacterium, has been identified as a virulence determinant in the initiation of IE. In this chapter, we will discuss the known biochemical, molecular, and structural aspects of this protein, including its interactions with extracellular matrix components and how this multifunctional adhesin may contribute to the pathogenicity of A. actinomycetemcomitans.
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Affiliation(s)
- Keith P. Mintz
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - David R. Danforth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT 05405, USA;
| | - Teresa Ruiz
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA;
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4
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Danforth DR, Melloni M, Thorpe R, Cohen A, Voogt R, Tristano J, Mintz KP. Dual function of the O-antigen WaaL ligase of Aggregatibacter actinomycetemcomitans. Mol Oral Microbiol 2023; 38:471-488. [PMID: 37941494 PMCID: PMC10758912 DOI: 10.1111/omi.12444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 07/14/2023] [Accepted: 10/26/2023] [Indexed: 11/10/2023]
Abstract
Protein glycosylation is critical to the quaternary structure and collagen-binding activity of the extracellular matrix protein adhesin A (EmaA) associated with Aggregatibacter actinomycetemcomitans. The glycosylation of this large, trimeric autotransporter adhesin is postulated to be mediated by WaaL, an enzyme with the canonical function to ligate the O-polysaccharide (O-PS) antigen with a terminal sugar of the lipid A-core oligosaccharide of lipopolysaccharide (LPS). In this study, we have determined that the Escherichia coli waaL ortholog (rflA) does not restore collagen binding of a waaL mutant strain of A. actinomycetemcomitans but does restore O-PS ligase activity following transformation of a plasmid expressing waaL. Therefore, a heterologous E. coli expression system was developed constituted of two independently replicating plasmids expressing either waaL or emaA of A. actinomycetemcomitans to directly demonstrate the necessity of ligase activity for EmaA collagen binding. Proper expression of the protein encoded by each plasmid was characterized, and the individually transformed strains did not promote collagen binding. However, coexpression of the two plasmids resulted in a strain with a significant increase in collagen binding activity and a change in the biochemical properties of the protein. These results provide additional data supporting the novel hypothesis that the WaaL ligase of A. actinomycetemcomitans shares a dual role as a ligase in LPS biosynthesis and is required for collagen binding activity of EmaA.
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Affiliation(s)
- David R. Danforth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Marcella Melloni
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Richard Thorpe
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Avi Cohen
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Richard Voogt
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Jake Tristano
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
| | - Keith P. Mintz
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT
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5
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Li KP, Tan DH, Ou SJ, Gong YS, Shien JH, Chang PC. Regions Important for Hemagglutination Activity and Serotypes of Avibacterium paragallinarum HMTp210 Protein. Avian Dis 2023; 67:153-159. [PMID: 37556294 DOI: 10.1637/aviandiseases-d-22-00084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 04/05/2023] [Indexed: 08/11/2023]
Abstract
Avibacterium paragallinarum is an important respiratory pathogen of domestic chickens. Avibacterium paragallinarum has been subtyped into three serogroups and nine serovars according to the Page and revised Kume schemes. The major hemagglutinin antigen of A. paragallinarum is HMTp210, which is a large protein of about 2000 amino acids (aa), including a 70-aa signal peptide at its N-terminal end. However, the regions important for the hemagglutination (HA) activity and serotypes of HMTp210 remain unclear. In this study we constructed a series of A. paragallinarum strains expressing HMTp210 in-frame deletion mutants and determined their HA titers to identify the regions important for the HA activity and serotypes of HMTp210. Two distinct types of HA activities were found in HMTp210. The type 1 HA activity resided in the region spanning the full-length HA (aa 71-2084), whereas the type 2 resided in the region spanning aa 1003-2084. The putative ligand binding of the type 1 HA activity was located at aa 176-360, which had a structure similar to YadA of Yersinia enterocolitica. The putative ligand binding site of the type 2 HA activity was located at aa 1003-1125, which had a structure similar to UspA1 from Moraxella catarrhalis. The type 1 HA activity appeared to be Page serogroup specific, whereas type 2 appeared to be Kume serovar specific. Finally, sequence analyses of the regions spanning aa 1-400 and aa 1100-1600 of HMTp210 could be useful for the molecular serotyping (the Page and revised Kume schemes) of A. paragallinarum isolates.
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Affiliation(s)
- K-P Li
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan
| | - D-H Tan
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan
| | - S-J Ou
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan
| | - Y-S Gong
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan
| | - J-H Shien
- Department of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan
| | - P-C Chang
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan,
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6
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Kiessling AR, Harris SA, Weimer KM, Wells G, Goldman A. The C-terminal head domain of Burkholderia pseudomallei BpaC has a striking hydrophilic core with an extensive solvent network. Mol Microbiol 2022; 118:77-91. [PMID: 35703459 PMCID: PMC9543794 DOI: 10.1111/mmi.14953] [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: 03/21/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/27/2022]
Abstract
Gram‐negative pathogens like Burkholderia pseudomallei use trimeric autotransporter adhesins such as BpaC as key molecules in their pathogenicity. Our 1.4 Å crystal structure of the membrane‐proximal part of the BpaC head domain shows that the domain is exclusively made of left‐handed parallel β‐roll repeats. This, the largest such structure solved, has two unique features. First, the core, rather than being composed of the canonical hydrophobic Ile and Val, is made up primarily of the hydrophilic Thr and Asn, with two different solvent channels. Second, comparing BpaC to all other left‐handed parallel β‐roll structures showed that the position of the head domain in the protein correlates with the number and type of charged residues. In BpaC, only negatively charged residues face the solvent—in stark contrast to the primarily positive surface charge of the left‐handed parallel β‐roll “type” protein, YadA. We propose extending the definitions of these head domains to include the BpaC‐like head domain as a separate subtype, based on its unusual sequence, position, and charge. We speculate that the function of left‐handed parallel β‐roll structures may differ depending on their position in the structure.
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Affiliation(s)
- Andreas R Kiessling
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Sarah A Harris
- Astbury Centre for Structural Molecular Biology, School of Physics and Astronomy, University of Leeds, Leeds, UK
| | - Kathleen M Weimer
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK.,IGBMC, School of Life and Health Sciences, University of Strasbourg, Strasbourg, France
| | - Geoffrey Wells
- UCL School of Pharmacy, University College London, London, UK
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK.,MIBS, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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7
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Genomic Analysis of Pasteurella atlantica Provides Insight on Its Virulence Factors and Phylogeny and Highlights the Potential of Reverse Vaccinology in Aquaculture. Microorganisms 2021; 9:microorganisms9061215. [PMID: 34199775 PMCID: PMC8226905 DOI: 10.3390/microorganisms9061215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/21/2021] [Accepted: 06/01/2021] [Indexed: 12/20/2022] Open
Abstract
Pasteurellosis in farmed lumpsuckers, Cyclopterus lumpus, has emerged as a serious disease in Norwegian aquaculture in recent years. Genomic characterization of the causative agent is essential in understanding the biology of the bacteria involved and in devising an efficient preventive strategy. The genomes of two clinical Pasteurella atlantica isolates were sequenced (≈2.3 Mbp), and phylogenetic analysis confirmed their position as a novel species within the Pasteurellaceae. In silico analyses revealed 11 genomic islands and 5 prophages, highlighting the potential of mobile elements as driving forces in the evolution of this species. The previously documented pathogenicity of P. atlantica is strongly supported by the current study, and 17 target genes were recognized as putative primary drivers of pathogenicity. The expression level of a predicted vaccine target, an uncharacterized adhesin protein, was significantly increased in both broth culture and following the exposure of P. atlantica to lumpsucker head kidney leucocytes. Based on in silico and functional analyses, the strongest gene target candidates will be prioritized in future vaccine development efforts to prevent future pasteurellosis outbreaks.
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8
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Dautin N. Folding Control in the Path of Type 5 Secretion. Toxins (Basel) 2021; 13:341. [PMID: 34064645 PMCID: PMC8151025 DOI: 10.3390/toxins13050341] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 12/17/2022] Open
Abstract
The type 5 secretion system (T5SS) is one of the more widespread secretion systems in Gram-negative bacteria. Proteins secreted by the T5SS are functionally diverse (toxins, adhesins, enzymes) and include numerous virulence factors. Mechanistically, the T5SS has long been considered the simplest of secretion systems, due to the paucity of proteins required for its functioning. Still, despite more than two decades of study, the exact process by which T5SS substrates attain their final destination and correct conformation is not totally deciphered. Moreover, the recent addition of new sub-families to the T5SS raises additional questions about this secretion mechanism. Central to the understanding of type 5 secretion is the question of protein folding, which needs to be carefully controlled in each of the bacterial cell compartments these proteins cross. Here, the biogenesis of proteins secreted by the Type 5 secretion system is discussed, with a focus on the various factors preventing or promoting protein folding during biogenesis.
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Affiliation(s)
- Nathalie Dautin
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université de Paris, LBPC-PM, CNRS, UMR7099, 75005 Paris, France;
- Institut de Biologie Physico-Chimique, Fondation Edmond de Rothschild pour le Développement de la Recherche Scientifique, 75005 Paris, France
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9
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Rooke JL, Icke C, Wells TJ, Rossiter AE, Browning DF, Morris FC, Leo JC, Schütz MS, Autenrieth IB, Cunningham AF, Linke D, Henderson IR. BamA and BamD Are Essential for the Secretion of Trimeric Autotransporter Adhesins. Front Microbiol 2021; 12:628879. [PMID: 33708185 PMCID: PMC7940764 DOI: 10.3389/fmicb.2021.628879] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022] Open
Abstract
The BAM complex in Escherichia coli is composed of five proteins, BamA-E. BamA and BamD are essential for cell viability and are required for the assembly of β-barrel outer membrane proteins. Consequently, BamA and BamD are indispensable for secretion via the classical autotransporter pathway (Type 5a secretion). In contrast, BamB, BamC, and BamE are not required for the biogenesis of classical autotransporters. Recently, we demonstrated that TamA, a homologue of BamA, and its partner protein TamB, were required for efficient secretion of proteins via the classical autotransporter pathway. The trimeric autotransporters are a subset of the Type 5-secreted proteins. Unlike the classical autotransporters, they are composed of three identical polypeptide chains which must be assembled together to allow secretion of their cognate passenger domains. In contrast to the classical autotransporters, the role of the Bam and Tam complex components in the biogenesis of the trimeric autotransporters has not been investigated fully. Here, using the Salmonella enterica trimeric autotransporter SadA and the structurally similar YadA protein of Yersinia spp., we identify the importance of BamA and BamD in the biogenesis of the trimeric autotransporters and reveal that BamB, BamC, BamE, TamA and TamB are not required for secretion of functional passenger domain on the cell surface. Importance The secretion of trimeric autotransporters (TAA's) has yet to be fully understood. Here we show that efficient secretion of TAAs requires the BamA and D proteins, but does not require BamB, C or E. In contrast to classical autotransporter secretion, neither trimeric autotransporter tested required TamA or B proteins to be functionally secreted.
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Affiliation(s)
- Jessica L Rooke
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD, Australia.,Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Christopher Icke
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD, Australia.,Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Timothy J Wells
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD, Australia.,The University of Queensland Diamantina Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Amanda E Rossiter
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Douglas F Browning
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Faye C Morris
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Jack C Leo
- Department of Biosciences, Nottingham Trent University, Nottingham, United Kingdom.,Department of Biosciences, University of Oslo, Oslo, Norway
| | - Monika S Schütz
- Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Ingo B Autenrieth
- Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Adam F Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Ian R Henderson
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD, Australia.,Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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Rahbar MR, Zarei M, Jahangiri A, Khalili S, Nezafat N, Negahdaripour M, Fattahian Y, Savardashtaki A, Ghasemi Y. Non-adaptive Evolution of Trimeric Autotransporters in Brucellaceae. Front Microbiol 2020; 11:560667. [PMID: 33281759 PMCID: PMC7688925 DOI: 10.3389/fmicb.2020.560667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 10/05/2020] [Indexed: 12/14/2022] Open
Abstract
Brucella species are Gram-negative, facultative intracellular pathogens. They are the main cause of brucellosis, which has led to a global health burden. Adherence of the pathogen to the host cells is the first step in the infection process. The bacteria can adhere to various biotic and abiotic surfaces using their outer membrane proteins. Trimeric autotransporter adhesins (TAAs) are modular homotrimers of various length and domain complexity. They are a diverse, and widespread gene family constituting the type Vc secretion pathway. These adhesins have been established as virulence factors in Brucellaceae. To date, no comprehensive and exhaustive study has been performed on the trimeric autotransporter family in the genus. In the present study, various bioinformatics tools were used to provide a novel evolutionary insight into the sequence and structure of this protein family in Brucellaceae. To this end, a dataset of all trimeric autotransporters from the Brucella genomes was built. Analyses included but were not limited to sequence alignment, phylogenetic tree constructions, codon-based test for selection, clustering of the sequences, and structure (primary to quaternary) predictions. Batch analyzes of the dataset suggested the existence of a few structural domains within the whole population. BatA from the B. abortus 2308 genome was selected as a reference to describe the features of these structural domains. Furthermore, we examined the structural basis for the observed rigidity and resiliency of the protein structure through a molecular dynamics evaluation, which led us to deduce that the random drift results in the non-adaptive evolution of the trimeric autotransporter genes in the Brucella genus. Notably, the modifications have occurred across the genus without interference of gene transmission.
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Affiliation(s)
- Mohammad Reza Rahbar
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahboubeh Zarei
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Saeed Khalili
- Department of Biology Sciences, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Navid Nezafat
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Manica Negahdaripour
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Yaser Fattahian
- Department of Biotechnology, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran
| | - Amir Savardashtaki
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Younes Ghasemi
- Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
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11
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Khalil HS, Øgaard J, Leo JC. Coaggregation properties of trimeric autotransporter adhesins. Microbiologyopen 2020; 9:e1109. [PMID: 32864901 PMCID: PMC7568254 DOI: 10.1002/mbo3.1109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 12/19/2022] Open
Abstract
Trimeric autotransporter adhesins (TAAs) comprise a group of virulence‐related proteins in Gram‐negative bacteria. Members of this family bind to extracellular matrix components such as collagen and fibronectin, but also they exhibit several other functions, such as conferring serum resistance and autoaggregation. Autoaggregation promoted by TAAs is homotypic and mediated by the sticky, globular head domains of these lollipop‐like molecules. However, whether TAAs mediate heterotypic interactions (i.e., coaggregation) has not been studied. To address this question, we investigated the coaggregation of two model TAA groups: YadA from the enteropathogenic Yersiniae and the immunoglobulin‐binding Eib proteins from Escherichia coli. To study TAA coaggregation, we coexpressed a fluorescent label together with a particular TAA and followed the aggregative interactions using fluorescence microscopy and quantified the interactions using a novel script implemented in Fiji. Our results show that there is coaggregation between some populations expressing different TAAs, which can be explained by relatively high sequence similarity between the interacting TAAs. Generally, the level of coaggregation correlated with the sequence similarity. However, some TAAs did not interact despite high sequence similarity, showing exclusion of bacteria producing a noncompatible TAA. These data demonstrate that TAAs can mediate bacterial coaggregation, but in some cases prevent coaggregation of bacteria with disparate TAAs. Our results have implications for the ecology of TAA‐producing bacteria, where coaggregation may promote co‐operation whereas exclusion might be an indication of competition.
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Affiliation(s)
- Hawzeen S Khalil
- Section for Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jonas Øgaard
- Research Institute of Internal Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Jack C Leo
- Section for Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway.,Antimicrobial Resistance, Omics and Microbiota Group, Department of Biosciences, School of Science and Technology, Nottingham Trent University, Nottingham, UK
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12
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Thibau A, Dichter AA, Vaca DJ, Linke D, Goldman A, Kempf VAJ. Immunogenicity of trimeric autotransporter adhesins and their potential as vaccine targets. Med Microbiol Immunol 2020; 209:243-263. [PMID: 31788746 PMCID: PMC7247748 DOI: 10.1007/s00430-019-00649-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022]
Abstract
The current problem of increasing antibiotic resistance and the resurgence of numerous infections indicate the need for novel vaccination strategies more than ever. In vaccine development, the search for and the selection of adequate vaccine antigens is the first important step. In recent years, bacterial outer membrane proteins have become of major interest, as they are the main proteins interacting with the extracellular environment. Trimeric autotransporter adhesins (TAAs) are important virulence factors in many Gram-negative bacteria, are localised on the bacterial surface, and mediate the first adherence to host cells in the course of infection. One example is the Neisseria adhesin A (NadA), which is currently used as a subunit in a licensed vaccine against Neisseria meningitidis. Other TAAs that seem promising vaccine candidates are the Acinetobacter trimeric autotransporter (Ata), the Haemophilus influenzae adhesin (Hia), and TAAs of the genus Bartonella. Here, we review the suitability of various TAAs as vaccine candidates.
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Affiliation(s)
- Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Alexander A. Dichter
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Diana J. Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK
- Molecular and Integrative Biosciences Program, University of Helsinki, Helsinki, Finland
| | - Volkhard A. J. Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
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Lomovatskaya LA, Romanenko AS. Secretion Systems of Bacterial Phytopathogens and Mutualists (Review). APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s0003683820020106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Ryoo D, Rydmark MO, Pang YT, Lundquist KP, Linke D, Gumbart JC. BamA is required for autotransporter secretion. Biochim Biophys Acta Gen Subj 2020; 1864:129581. [PMID: 32114025 DOI: 10.1016/j.bbagen.2020.129581] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 02/01/2020] [Accepted: 02/22/2020] [Indexed: 01/24/2023]
Abstract
BACKGROUND In Gram-negative bacteria, type Va and Vc autotransporters are proteins that contain both a secreted virulence factor (the "passenger" domain) and a β-barrel that aids its export. While it is known that the folding and insertion of the β-barrel domain utilize the β-barrel assembly machinery (BAM) complex, how the passenger domain is secreted and folded across the membrane remains to be determined. The hairpin model states that passenger domain secretion occurs independently through the fully-formed and membrane-inserted β-barrel domain via a hairpin folding intermediate. In contrast, the BamA-assisted model states that the passenger domain is secreted through a hybrid of BamA, the essential subunit of the BAM complex, and the β-barrel domain of the autotransporter. METHODS To ascertain the models' plausibility, we have used molecular dynamics to simulate passenger domain secretion for two autotransporters, EspP and YadA. RESULTS We observed that each protein's β-barrel is unable to accommodate the secreting passenger domain in a hairpin configuration without major structural distortions. Additionally, the force required for secretion through EspP's β-barrel is more than that through the BamA β-barrel. CONCLUSIONS Secretion of autotransporters most likely occurs through an incompletely formed β-barrel domain of the autotransporter in conjunction with BamA. GENERAL SIGNIFICANCE Secretion of virulence factors is a process used by practically all pathogenic Gram-negative bacteria. Understanding this process is a necessary step towards limiting their infectious capacity.
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Affiliation(s)
- David Ryoo
- Interdisciplinary Bioengineering Graduate Program, Georgia Institute of Technology, Atlanta, GA 30332, United States of America
| | | | - Yui Tik Pang
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30313, United States of America
| | - Karl P Lundquist
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, United States of America
| | - Dirk Linke
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30313, United States of America.
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Vaca DJ, Thibau A, Schütz M, Kraiczy P, Happonen L, Malmström J, Kempf VAJ. Interaction with the host: the role of fibronectin and extracellular matrix proteins in the adhesion of Gram-negative bacteria. Med Microbiol Immunol 2019; 209:277-299. [PMID: 31784893 PMCID: PMC7248048 DOI: 10.1007/s00430-019-00644-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/14/2019] [Indexed: 01/03/2023]
Abstract
The capacity of pathogenic microorganisms to adhere to host cells and avoid clearance by the host immune system is the initial and most decisive step leading to infections. Bacteria have developed different strategies to attach to diverse host surface structures. One important strategy is the adhesion to extracellular matrix (ECM) proteins (e.g., collagen, fibronectin, laminin) that are highly abundant in connective tissue and basement membranes. Gram-negative bacteria express variable outer membrane proteins (adhesins) to attach to the host and to initiate the process of infection. Understanding the underlying molecular mechanisms of bacterial adhesion is a prerequisite for targeting this interaction by “anti-ligands” to prevent colonization or infection of the host. Future development of such “anti-ligands” (specifically interfering with bacteria-host matrix interactions) might result in the development of a new class of anti-infective drugs for the therapy of infections caused by multidrug-resistant Gram-negative bacteria. This review summarizes our current knowledge about the manifold interactions of adhesins expressed by Gram-negative bacteria with ECM proteins and the use of this information for the generation of novel therapeutic antivirulence strategies.
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Affiliation(s)
- Diana J Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Monika Schütz
- Institute for Medical Microbiology and Infection Control, University Hospital, Eberhard Karls-University, Tübingen, Germany
| | - Peter Kraiczy
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Johan Malmström
- Division of Infection Medicine, Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Volkhard A J Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University Frankfurt am Main, Paul-Ehrlich-Str. 40, 60596, Frankfurt, Germany.
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Sequential Translocation of Polypeptides across the Bacterial Outer Membrane through the Trimeric Autotransporter Pathway. mBio 2019; 10:mBio.01973-19. [PMID: 31641085 PMCID: PMC6805991 DOI: 10.1128/mbio.01973-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Trimeric autotransporter adhesins (TAAs) are a family of bacterial outer membrane (OM) proteins that are comprised of three identical subunits. Each subunit contains an N-terminal extracellular ("passenger") domain and a short C-terminal segment that contributes four β strands to a single 12-stranded β barrel. The mechanism by which the passenger domains are translocated across the OM and the energetics of the translocation reaction are poorly understood. To address these issues, we examined the secretion of modified versions of the passenger domain of UpaG, a TAA produced by Escherichia coli CFT073. Using the SpyTag-SpyCatcher system to probe passenger domain localization, we found that both intrinsically disordered polypeptides fused to the UpaG passenger domain and artificially disulfide-bonded polypeptides were secreted effectively but relatively slowly. Surprisingly, we also found that in some cases, the three nonnative passenger domain segments associated with a single trimer were secreted sequentially. Photo-cross-linking experiments indicated that incompletely assembled UpaG derivatives remained bound to the barrel assembly machinery (Bam) complex until all three passenger domains were fully secreted. Taken together, our results strongly suggest that the secretion of polypeptides through the TAA pathway is coordinated with the assembly of the β barrel domain and that the folding of passenger domains in the extracellular space maximizes the rate of secretion. Furthermore, our work provides evidence for an unprecedented sequential mode of protein translocation, at least under specific experimental conditions.IMPORTANCE Trimeric autotransporter adhesins (TAAs) are specialized bacterial outer membrane proteins consisting of three identical subunits. TAAs contain large extracellular domains that trimerize and promote virulence, but the mechanism by which they are secreted is poorly understood. We found that the extracellular domains of a native TAA were secreted rapidly but that disordered and artificially folded polypeptides fused to native passenger domains were secreted in a slow, sequential fashion. Our results strongly suggest that the efficient secretion of native extracellular domains is driven by their trimerization following export but that alternative energy sources can be harnessed to secrete nonnative polypeptides. Furthermore, we obtained evidence that TAA extracellular domains are secreted before the assembly of the linked membrane spanning domain is completed.
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Pierce into the Native Structure of Ata, a Trimeric Autotransporter of Acinetobacter baumannii ATCC 17978. Int J Pept Res Ther 2019. [DOI: 10.1007/s10989-019-09920-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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Mikula KM, Kolodziejczyk R, Goldman A. Structure of the UspA1 protein fragment from Moraxella catarrhalis responsible for C3d binding. J Struct Biol 2019; 208:77-85. [PMID: 31400508 PMCID: PMC6839023 DOI: 10.1016/j.jsb.2019.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/03/2019] [Accepted: 08/05/2019] [Indexed: 01/26/2023]
Abstract
UspA1299–452 is a left-handed coiled-coil structure that follows TAA rules. Structure of UspA1299–452 contains part of the long neck domain and of the stalk. UspA1-C3d binding does not saturate at C3d physiological concentrations. The binding constant as measured by thermophoresis is at least 140 μM. Full-length proteins or other factors are important for UspA1-C3d interactions.
The gram-negative bacterium Moraxella catarrhalis infects humans exclusively, causing various respiratory tract diseases, including acute otitis media in children, septicaemia or meningitis in adults, and pneumonia in the elderly. To do so, M. catarrhalis expresses virulence factors facilitating its entry and survival in the host. Among them are the ubiquitous surface proteins (Usps): A1, A2, and A2H, which all belong to the trimeric autotransporter adhesin family. They bind extracellular matrix molecules and inhibit the classical and alternative pathways of the complement cascade by recruiting complement regulators C3d and C4b binding protein. Here, we report the 2.5 Å resolution X-ray structure of UspA1299–452, which previous work had suggested contained the canonical C3d binding site found in both UspA1 and UspA2. We show that this fragment of the passenger domain contains part of the long neck domain (residues 299–336) and a fragment of the stalk (residues 337–452). The coiled-coil stalk is left-handed, with 7 polar residues from each chain facing the core and coordinating chloride ions or water molecules. Despite the previous reports of tight binding in serum-based assays, we were not able to demonstrate binding between C3d and UspA1299–452 using ELISA or biolayer interferometry, and the two proteins run separately on size-exclusion chromatography. Microscale thermophoresis suggested that the dissociation constant was 140.5 ± 8.4 μM. We therefore suggest that full-length proteins or other additional factors are important in UspA1-C3d interactions. Other molecules on the bacterial surface or present in serum may enhance binding of those two molecules.
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Affiliation(s)
- Kornelia M Mikula
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Robert Kolodziejczyk
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Adrian Goldman
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland; Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK.
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19
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Interactions between the Trimeric Autotransporter Adhesin EmaA and Collagen Revealed by Three-Dimensional Electron Tomography. J Bacteriol 2019; 201:JB.00297-19. [PMID: 31160398 DOI: 10.1128/jb.00297-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 05/24/2019] [Indexed: 11/20/2022] Open
Abstract
Bacterial adhesion to host tissues is considered the first and critical step of microbial infection. The extracellular matrix protein adhesin A (EmaA) is a collagen-binding adhesin of the periodontal pathogen Aggregatibacter actinomycetemcomitans Three 202-kDa EmaA monomers form antenna-like structures on the bacterial surface with the functional domain located at the apical end. The structure of the 30-nm functional domain has been determined by three-dimensional (3D) electron tomography and subvolume averaging. The region exhibits a complex architecture composed of three subdomains (SI to SIII) and a linker between subdomains SII and SIII. However, the molecular interaction between the adhesin receptor complexes has yet to be revealed. This study provides the first detailed 3D structure of reconstituted EmaA/collagen complexes obtained using 3D electron tomography and image processing techniques. The observed interactions of EmaA with collagen were not to whole, intact fibrils, but rather to individual collagen triple helices dissociated from the fibrils. The majority of the contacts with the EmaA functional domain encompassed subdomains SII and SIII and in some cases the tip of the apical domain, involving SI. These data suggest a multipronged mechanism for the interaction of Gram-negative bacteria with collagen.IMPORTANCE Bacterial adhesion is a crucial step for bacterial colonization and infection. In recent years, the number of antibiotic-resistant strains has dramatically increased; therefore, there is a need to search for novel antimicrobial agents. Thus, great efforts are being devoted to develop a clear understanding of the bacterial adhesion mechanism for preventing infections. In host/pathogen interactions, once repulsive forces are overcome, adhesins recognize and tightly bind to specific receptors on the host cell or tissue components. Here, we present the first 3D structure of the interaction between the collagen-binding adhesin EmaA and collagen, which is critical for the development of endocarditis in humans.
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20
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Paxman JJ, Lo AW, Sullivan MJ, Panjikar S, Kuiper M, Whitten AE, Wang G, Luan CH, Moriel DG, Tan L, Peters KM, Phan MD, Gee CL, Ulett GC, Schembri MA, Heras B. Unique structural features of a bacterial autotransporter adhesin suggest mechanisms for interaction with host macromolecules. Nat Commun 2019; 10:1967. [PMID: 31036849 PMCID: PMC6488583 DOI: 10.1038/s41467-019-09814-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/28/2019] [Indexed: 12/31/2022] Open
Abstract
Autotransporters are the largest family of outer membrane and secreted proteins in Gram-negative bacteria. Most autotransporters are localised to the bacterial surface where they promote colonisation of host epithelial surfaces. Here we present the crystal structure of UpaB, an autotransporter that is known to contribute to uropathogenic E. coli (UPEC) colonisation of the urinary tract. We provide evidence that UpaB can interact with glycosaminoglycans and host fibronectin. Unique modifications to its core β-helical structure create a groove on one side of the protein for interaction with glycosaminoglycans, while the opposite face can bind fibronectin. Our findings reveal far greater diversity in the autotransporter β-helix than previously thought, and suggest that this domain can interact with host macromolecules. The relevance of these interactions during infection remains unclear.
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Affiliation(s)
- Jason J Paxman
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, VIC, Australia
| | - Alvin W Lo
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Matthew J Sullivan
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, 4222, QLD, Australia
| | - Santosh Panjikar
- Macromolecular Crystallography, Australian Synchrotron, Clayton, 3168, VIC, Australia
- Department of Molecular Biology and Biochemistry, Monash University, Melbourne, 3800, VIC, Australia
| | - Michael Kuiper
- Molecular & Materials Modelling group Data61, CSIRO, Docklands, Melbourne, 8012, VIC, Australia
| | - Andrew E Whitten
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, 2234, NSW, Australia
| | - Geqing Wang
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, VIC, Australia
| | - Chi-Hao Luan
- High Throughput Analysis Laboratory and Department of Molecular Biosciences, Northwestern University, Chicago, 60208, IL, USA
| | - Danilo G Moriel
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Kate M Peters
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia
| | - Christine L Gee
- Macromolecular Crystallography, Australian Synchrotron, Clayton, 3168, VIC, Australia
| | - Glen C Ulett
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, 4222, QLD, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, 4072, QLD, Australia.
| | - Begoña Heras
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, 3086, VIC, Australia.
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García-Bayona L, Gozzi K, Laub MT. Mechanisms of Resistance to the Contact-Dependent Bacteriocin CdzC/D in Caulobacter crescentus. J Bacteriol 2019; 201:e00538-18. [PMID: 30692171 PMCID: PMC6436349 DOI: 10.1128/jb.00538-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/22/2019] [Indexed: 01/02/2023] Open
Abstract
The Cdz bacteriocin system allows the aquatic oligotrophic bacterium Caulobacter crescentus to kill closely related species in a contact-dependent manner. The toxin, which aggregates on the surfaces of producer cells, is composed of two small hydrophobic proteins, CdzC and CdzD, each bearing an extended glycine-zipper motif, that together induce inner membrane depolarization and kill target cells. To further characterize the mechanism of Cdz delivery and toxicity, we screened for mutations that render a target strain resistant to Cdz-mediated killing. These mutations mapped to four loci, including a TonB-dependent receptor, a three-gene operon (named zerRAB for zipper envelope resistance), and perA (for pentapeptide envelope resistance). Mutations in the zerRAB locus led to its overproduction and to potential changes in cell envelope composition, which may diminish the susceptibility of cells to Cdz toxins. The perA gene is also required to maintain a normal cell envelope, but our screen identified mutations that confer resistance to Cdz toxins without substantially affecting the cell envelope functions of PerA. We demonstrate that PerA, which encodes a pentapeptide repeat protein predicted to form a quadrilateral β-helix, localizes primarily to the outer membrane of cells, where it may serve as a receptor for the Cdz toxins. Collectively, these results provide new insights into the function and mechanisms of an atypical, contact-dependent bacteriocin system.IMPORTANCE Bacteriocins are commonly used by bacteria to kill neighboring cells that compete for resources. Although most bacteriocins are secreted, the aquatic, oligotrophic bacterium Caulobacter crescentus produces a two-peptide bacteriocin, CdzC/D, that remains attached to the outer membranes of cells, enabling contact-dependent killing of cells lacking the immunity protein CdzI. The receptor for CdzC/D has not previously been reported. Here, we describe a genetic screen for mutations that confer resistance to CdzC/D. One locus identified, perA, encodes a pentapeptide repeat protein that resides in the outer membrane of target cells, where it may act as the direct receptor for CdzC/D. Collectively, our results provide new insight into bacteriocin function and diversity.
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Affiliation(s)
- Leonor García-Bayona
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Cambridge, Massachusetts, USA
- Graduate Program in Microbiology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kevin Gozzi
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Cambridge, Massachusetts, USA
- Graduate Program in Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Michael T Laub
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Cambridge, Massachusetts, USA
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Chauhan N, Hatlem D, Orwick-Rydmark M, Schneider K, Floetenmeyer M, van Rossum B, Leo JC, Linke D. Insights into the autotransport process of a trimeric autotransporter, Yersinia Adhesin A (YadA). Mol Microbiol 2019; 111:844-862. [DOI: 10.1111/mmi.14195] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Nandini Chauhan
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
| | - Daniel Hatlem
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
| | | | - Kenneth Schneider
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
| | - Matthias Floetenmeyer
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
- The Centre for Microscopy and Microanalysis, The University of Queensland; 4072 St. Lucia Queensland Australia
| | - Barth van Rossum
- Forschungsinstitut für Molekulare Pharmakologie; Department of NMR-Supported Structural Biology; Berlin Germany
| | - Jack C. Leo
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
| | - Dirk Linke
- Department of Biosciences; University of Oslo; Blindernveien 31 0371 Oslo Norway
- Max Planck Institute for Developmental Biology, Department 1; 72076 Tübingen Germany
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23
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Abstract
Type V, or "autotransporter," secretion is a term used to refer to several simple protein export pathways that are found in a wide range of Gram-negative bacteria. Autotransporters are generally single polypeptides that consist of an extracellular ("passenger") domain and a β barrel domain that anchors the protein to the outer membrane (OM). Although it was originally proposed that the passenger domain is secreted through a channel formed solely by the covalently linked β barrel domain, experiments performed primarily on the type Va, or "classical," autotransporter pathway have challenged this hypothesis. Several lines of evidence strongly suggest that both the secretion of the passenger domain and the membrane integration of the β barrel domain are catalyzed by the barrel assembly machinery (Bam) complex, a conserved hetero-oligomer that plays an essential role in the assembly of most integral OM proteins. The secretion reaction appears to be driven at least in part by the folding of the passenger domain in the extracellular space. Although many aspects of autotransporter biogenesis remain to be elucidated, it will be especially interesting to determine whether the different classes of proteins that fall under the type V rubric-most of which have not been examined in detail-are assembled by the same basic mechanism as classical autotransporters.
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Rapid detection of extra-intestinal pathogenic Escherichia coli multi-locus sequence type 127 using a specific PCR assay. J Med Microbiol 2019; 68:188-196. [DOI: 10.1099/jmm.0.000902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Alex A, Antunes A. Genus-wide comparison of Pseudovibrio bacterial genomes reveal diverse adaptations to different marine invertebrate hosts. PLoS One 2018; 13:e0194368. [PMID: 29775460 PMCID: PMC5959193 DOI: 10.1371/journal.pone.0194368] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 03/01/2018] [Indexed: 11/18/2022] Open
Abstract
Bacteria belonging to the genus Pseudovibrio have been frequently found in association with a wide variety of marine eukaryotic invertebrate hosts, indicative of their versatile and symbiotic lifestyle. A recent comparison of the sponge-associated Pseudovibrio genomes has shed light on the mechanisms influencing a successful symbiotic association with sponges. In contrast, the genomic architecture of Pseudovibrio bacteria associated with other marine hosts has received less attention. Here, we performed genus-wide comparative analyses of 18 Pseudovibrio isolated from sponges, coral, tunicates, flatworm, and seawater. The analyses revealed a certain degree of commonality among the majority of sponge- and coral-associated bacteria. Isolates from other marine invertebrate host, tunicates, exhibited a genetic repertoire for cold adaptation and specific metabolic abilities including mucin degradation in the Antarctic tunicate-associated bacterium Pseudovibrio sp. Tun.PHSC04_5.I4. Reductive genome evolution was simultaneously detected in the flatworm-associated bacteria and the sponge-associated bacterium P. axinellae AD2, through the loss of major secretion systems (type III/VI) and virulence/symbioses factors such as proteins involved in adhesion and attachment to the host. Our study also unraveled the presence of a CRISPR-Cas system in P. stylochi UST20140214-052 a flatworm-associated bacterium possibly suggesting the role of CRISPR-based adaptive immune system against the invading virus particles. Detection of mobile elements and genomic islands (GIs) in all bacterial members highlighted the role of horizontal gene transfer for the acquisition of novel genetic features, likely enhancing the bacterial ecological fitness. These findings are insightful to understand the role of genome diversity in Pseudovibrio as an evolutionary strategy to increase their colonizing success across a wide range of marine eukaryotic hosts.
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Affiliation(s)
- Anoop Alex
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- * E-mail: (AA); (AA)
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- * E-mail: (AA); (AA)
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Tsugo K, Nakamura SI, Yamanaka H, Une Y. A study on the efficacy of the recombinant Yersinia adhesin A vaccine against yersiniosis in the early phase. J Vet Med Sci 2017; 79:855-863. [PMID: 28320976 PMCID: PMC5447973 DOI: 10.1292/jvms.16-0528] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Yersinia pseudotuberculosis (Y. ptb) is a zoonotic pathogenic bacterial species of the family Enterobacteriaceae and causes yersiniosis, an acute intestinal infection in humans and animals.
Y. ptb is often implicated in lethal epidemics in zoo animals and reductions in the breeding population, but a valid prevention method has not been established. Therefore, this study aimed to develop a vaccine
for yersiniosis control. The immunogenicity of one of the adhesion factors involved in pathogenic mechanisms of Y. ptb, Yersinia adhesin A (YadA), was investigated. BALB/c mice were divided into 3
groups: in group 1, mice received insoluble recombinant YadA (rYadA) produced in genetically engineered Escherichia coli (100 µg/dose); in group 2, mice received inactivated Y.
ptb with strong expression of YadA (20 mg/dose);and in group 3, mice received phosphate-buffered saline (0.2 ml/dose). All interventions were administered subcutaneously twice at an interval of 1 week.
One week after the second administration, Y. ptb (107 cells/mouse) was inoculated orally. As a result, the survival rate was 100% in group 1, 60% in group 2, and 0% in group 3. The anti-YadA antibody
titer increased in a stepwise fashion in groups 1 and 2. The present study results suggest that rYadA shows promise as a protective antigen against yersiniosis. This study concluded that vaccination against Y. ptb
may become available as a new method to prevent lethal epidemics in animals.
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Affiliation(s)
- Kosuke Tsugo
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Shin-Ichi Nakamura
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Hiroko Yamanaka
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Yumi Une
- Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
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Wright J, Thomsen M, Kolodziejczyk R, Ridley J, Sinclair J, Carrington G, Singh B, Riesbeck K, Goldman A. The crystal structure of PD1, a Haemophilus surface fibril domain. Acta Crystallogr F Struct Biol Commun 2017; 73:101-108. [PMID: 28177321 PMCID: PMC5297931 DOI: 10.1107/s2053230x17001406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/27/2017] [Indexed: 11/12/2022] Open
Abstract
The Haemophilus surface fibril (Hsf) is an unusually large trimeric autotransporter adhesin (TAA) expressed by the most virulent strains of H. influenzae. Hsf is known to mediate adhesion between pathogen and host, allowing the establishment of potentially deadly diseases such as epiglottitis, meningitis and pneumonia. While recent research has suggested that this TAA might adopt a novel `hairpin-like' architecture, the characterization of Hsf has been limited to in silico modelling and electron micrographs, with no high-resolution structural data available. Here, the crystal structure of Hsf putative domain 1 (PD1) is reported at 3.3 Å resolution. The structure corrects the previous domain annotation by revealing the presence of an unexpected N-terminal TrpRing domain. PD1 represents the first Hsf domain to be solved, and thus paves the way for further research on the `hairpin-like' hypothesis.
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Affiliation(s)
- Jack Wright
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
| | - Maren Thomsen
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
| | - Robert Kolodziejczyk
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
- Pure Biologics Ltd, Dunska 11, 54-427 Wroclaw, Poland
| | - Joshua Ridley
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
| | - Jessica Sinclair
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
| | - Glenn Carrington
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
| | - Birendra Singh
- Department of Clinical Microbiology, Lund University, Jan Waldenströms gata 59, SE-205 02 Malmö, Sweden
| | - Kristian Riesbeck
- Department of Clinical Microbiology, Lund University, Jan Waldenströms gata 59, SE-205 02 Malmö, Sweden
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Science, University of Leeds, Leeds LS2 9JT, England
- Division of Biochemistry, University of Helsinki, FIN-00014 Helsinki, Finland
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Abstract
Type V secretion denotes a variety of secretion systems that cross the outer membrane in Gram-negative bacteria but that depend on the Sec machinery for transport through the inner membrane. They are possibly the simplest bacterial secretion systems, because they consist only of a single polypeptide chain (or two chains in the case of two-partner secretion). Their seemingly autonomous transport through the outer membrane has led to the term "autotransporters" for various subclasses of type V secretion. In this chapter, we review the structure and function of these transporters and review recent findings on additional factors involved in the secretion process, which have put the term "autotransporter" to debate.
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Mühlenkamp MC, Hallström T, Autenrieth IB, Bohn E, Linke D, Rinker J, Riesbeck K, Singh B, Leo JC, Hammerschmidt S, Zipfel PF, Schütz MS. Vitronectin Binds to a Specific Stretch within the Head Region of Yersinia Adhesin A and Thereby Modulates Yersinia enterocolitica Host Interaction. J Innate Immun 2016; 9:33-51. [PMID: 27798934 DOI: 10.1159/000449200] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/17/2016] [Indexed: 01/02/2023] Open
Abstract
Complement resistance is an important virulence trait of Yersinia enterocolitica (Ye). The predominant virulence factor expressed by Ye is Yersinia adhesin A (YadA), which enables bacterial attachment to host cells and extracellular matrix and additionally allows the acquisition of soluble serum factors. The serum glycoprotein vitronectin (Vn) acts as an inhibitory regulator of the terminal complement complex by inhibiting the lytic pore formation. Here, we show YadA-mediated direct interaction of Ye with Vn and investigated the role of this Vn binding during mouse infection in vivo. Using different Yersinia strains, we identified a short stretch in the YadA head domain of Ye O:9 E40, similar to the 'uptake region' of Y. pseudotuberculosis YPIII YadA, as crucial for efficient Vn binding. Using recombinant fragments of Vn, we found the C-terminal part of Vn, including heparin-binding domain 3, to be responsible for binding to YadA. Moreover, we found that Vn bound to the bacterial surface is still functionally active and thus inhibits C5b-9 formation. In a mouse infection model, we demonstrate that Vn reduces complement-mediated killing of Ye O:9 E40 and, thus, improved bacterial survival. Taken together, these findings show that YadA-mediated Vn binding influences Ye pathogenesis.
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Affiliation(s)
- Melanie C Mühlenkamp
- Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany
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Pakharukova N, Roy S, Tuittila M, Rahman MM, Paavilainen S, Ingars AK, Skaldin M, Lamminmäki U, Härd T, Teneberg S, Zavialov AV. Structural basis for Myf and Psa fimbriae-mediated tropism of pathogenic strains of Yersinia for host tissues. Mol Microbiol 2016; 102:593-610. [PMID: 27507539 DOI: 10.1111/mmi.13481] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2016] [Indexed: 02/06/2023]
Abstract
Three pathogenic species of the genus Yersinia assemble adhesive fimbriae via the FGL-chaperone/usher pathway. Closely related Y. pestis and Y. pseudotuberculosis elaborate the pH6 antigen (Psa), which mediates bacterial attachment to alveolar cells of the lung. Y. enterocolitica, instead, assembles the homologous fimbriae Myf of unknown function. Here, we discovered that Myf, like Psa, specifically recognizes β1-3- or β1-4-linked galactose in glycosphingolipids, but completely lacks affinity for phosphatidylcholine, the main receptor for Psa in alveolar cells. The crystal structure of a subunit of Psa (PsaA) complexed with choline together with mutagenesis experiments revealed that PsaA has four phosphatidylcholine binding pockets that enable super-high-avidity binding of Psa-fibres to cell membranes. The pockets are arranged as six tyrosine residues, which are all missing in the MyfA subunit of Myf. Conversely, the crystal structure of the MyfA-galactose complex revealed that the galactose-binding site is more extended in MyfA, enabling tighter binding to lactosyl moieties. Our results suggest that during evolution, Psa has acquired a tyrosine-rich surface that enables it to bind to phosphatidylcholine and mediate adhesion of Y. pestis/pseudotuberculosis to alveolar cells, whereas Myf has specialized as a carbohydrate-binding adhesin, facilitating the attachment of Y. enterocolitica to intestinal cells.
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Affiliation(s)
- Natalia Pakharukova
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Saumendra Roy
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
| | - Minna Tuittila
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Mohammad M Rahman
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Sari Paavilainen
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland
| | - Anna-Karin Ingars
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, P.O. BOX 440, Göteborg, 40530, Sweden
| | - Maksym Skaldin
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Biochemistry/Biotechnology, University of Turku, Tykistökatu 6A, Turku, 20014, Finland
| | - Urpo Lamminmäki
- Department of Biochemistry/Biotechnology, University of Turku, Tykistökatu 6A, Turku, 20014, Finland
| | - Torleif Härd
- Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, P.O. BOX 440, Göteborg, 40530, Sweden
| | - Anton V Zavialov
- Department of Chemistry, University of Turku, Turku, Joint Biotechnology Laboratory, Arcanum, Vatselankatu 2, Turku, 20500, Finland.,Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCentre, P.O. BOX 7016, Uppsala, 75007, Sweden
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Sasaki H, Ishikawa H, Terayama H, Asano R, Kawamoto E, Ishibashi H, Boot R. Identification of a virulence determinant that is conserved in the Jawetz and Heyl biotypes of [Pasteurella] pneumotropica. Pathog Dis 2016; 74:ftw066. [PMID: 27402782 DOI: 10.1093/femspd/ftw066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2016] [Indexed: 11/12/2022] Open
Abstract
[Pasteurella] pneumotropica is a ubiquitous bacterium frequently isolated from laboratory rodents. Although this bacterium causes various diseases in immunosuppressed animals, little is known about major virulence factors and their roles in pathogenicity. To identify virulence factors, we sequenced the genome of [P.] pneumotropica biotype Heyl strain ATCC 12555, and compared the resulting non-contiguous draft genome sequence with the genome of biotype Jawetz strain ATCC 35149. Among a large number of genes encoding virulence-associated factors in both strains, four genes encoding for YadA-like proteins, which are known virulence factors that function in host cell adherence and invasion in many pathogens. In this study, we assessed YadA distribution and biological activity as an example of one of virulence-associated factor shared, with biotype Jawetz and Heyl. More than half of mouse isolates were found to have at least one of these genes; whereas, the majority of rat isolates did not. Autoagglutination activity, and ability to bind to mouse collagen type IV and mouse fibroblast cells, was significantly higher in YadA-positive than YadA-negative strains. To conclude, we identified a large number of candidate genes predicted to influence [P.] pneumotropica pathogenesis.
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Affiliation(s)
- Hiraku Sasaki
- Department of Health Science, School of Health and Sports Science, Juntendo University, 1-1 Hiraga-gakuendai, Inzai, Chiba 270-1695, Japan
| | - Hiroki Ishikawa
- Department of Microbiology and Immunology, Showa University School of Medicine, 1-5-8 Hatanodai, Tokyo 142-8555, Japan
| | - Hayato Terayama
- Department of Anatomy, Division of Basic Medical Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 259-1193, Japan
| | - Ryoki Asano
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University, 41-438 Kaidobata-Nishi, Shimoshinjo-Nakano, Akita 010-0195, Japan
| | - Eiichi Kawamoto
- Animal Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Tokyo 160-8402, Japan
| | - Hidetoshi Ishibashi
- Animal Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Tokyo 160-8402, Japan
| | - Ron Boot
- National Institute of Public Health and the Environment, Antonie van Leeuwenhoeklaan 9 3721 MA Bilthoven, the Netherlands
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Abstract
UNLABELLED Moraxella catarrhalis is a human respiratory pathogen that causes acute otitis media in children and is associated with exacerbations in patients suffering from chronic obstructive pulmonary disease (COPD). The first step in M. catarrhalis colonization is adherence to the mucosa, epithelial cells, and extracellular matrix (ECM). The objective of this study was to evaluate the role of M. catarrhalis interactions with collagens from various angles. Clinical isolates (n= 43) were tested for collagen binding, followed by a detailed analysis of protein-protein interactions using recombinantly expressed proteins.M. catarrhalis-dependent interactions with collagen produced by human lung fibroblasts and tracheal tissues were studied by utilizing confocal immunohistochemistry and high-resolution scanning electron microscopy. A mouse smoke-induced chronic obstructive pulmonary disease (COPD) model was used to estimate the adherence of M. catarrhalis in vivo. We found that all M. catarrhalis clinical isolates tested adhered to fibrillar collagen types I, II, and III and network-forming collagens IV and VI. The trimeric autotransporter adhesins ubiquitous surface protein A2(UspA2) and UspA2H were identified as major collagen-binding receptors.M. catarrhalis wild type adhered to human tracheal tissue and collagen-producing lung fibroblasts, whereas UspA2 and UspA2H deletion mutants did not. Moreover, in the COPD mouse model, bacteria devoid of UspA2 and UspA2H had a reduced level of adherence to the respiratory tract compared to the adherence of wild-type bacteria. Our data therefore suggest that theM. catarrhalisUspA2 and UspA2H-dependent interaction with collagens is highly critical for adherence in the host and, furthermore, may play an important role in the establishment of disease. IMPORTANCE The respiratory tract pathogen Moraxella catarrhalis adheres to the host by interacting with several components, including the ECM. Collagen accounts for 30% of total body proteins, and therefore, bacterial adherence to abundant host collagens mediates bacterial persistence and colonization. In this study, we characterized previously unknown M. catarrhalis-dependent interactions with host collagens and found that the trimeric autotransporter adhesins ubiquitous surface protein A2(UspA2) and UspA2H are highly important. Our observations also suggested that collagen-mediated adherence ofM. catarrhalis is indispensable for bacterial survival in the host, as exemplified by a mouse COPD model.
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Louros NN, Baltoumas FA, Hamodrakas SJ, Iconomidou VA. A β-solenoid model of the Pmel17 repeat domain: insights to the formation of functional amyloid fibrils. J Comput Aided Mol Des 2016; 30:153-64. [PMID: 26754844 DOI: 10.1007/s10822-015-9892-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022]
Abstract
Pmel17 is a multidomain protein involved in biosynthesis of melanin. This process is facilitated by the formation of Pmel17 amyloid fibrils that serve as a scaffold, important for pigment deposition in melanosomes. A specific luminal domain of human Pmel17, containing 10 tandem imperfect repeats, designated as repeat domain (RPT), forms amyloid fibrils in a pH-controlled mechanism in vitro and has been proposed to be essential for the formation of the fibrillar matrix. Currently, no three-dimensional structure has been resolved for the RPT domain of Pmel17. Here, we examine the structure of the RPT domain by performing sequence threading. The resulting model was subjected to energy minimization and validated through extensive molecular dynamics simulations. Structural analysis indicated that the RPT model exhibits several distinct properties of β-solenoid structures, which have been proposed to be polymerizing components of amyloid fibrils. The derived model is stabilized by an extensive network of hydrogen bonds generated by stacking of highly conserved polar residues of the RPT domain. Furthermore, the key role of invariant glutamate residues is proposed, supporting a pH-dependent mechanism for RPT domain assembly. Conclusively, our work attempts to provide structural insights into the RPT domain structure and to elucidate its contribution to Pmel17 amyloid fibril formation.
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Affiliation(s)
- Nikolaos N Louros
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, 157 01, Athens, Greece
| | - Fotis A Baltoumas
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, 157 01, Athens, Greece
| | - Stavros J Hamodrakas
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, 157 01, Athens, Greece
| | - Vassiliki A Iconomidou
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, 157 01, Athens, Greece.
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Koiwai K, Hartmann MD, Linke D, Lupas AN, Hori K. Structural Basis for Toughness and Flexibility in the C-terminal Passenger Domain of an Acinetobacter Trimeric Autotransporter Adhesin. J Biol Chem 2015; 291:3705-24. [PMID: 26698633 DOI: 10.1074/jbc.m115.701698] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Indexed: 11/06/2022] Open
Abstract
Trimeric autotransporter adhesins (TAAs) on the cell surface of Gram-negative pathogens mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific high adhesiveness to abiotic material surfaces as well as to biotic surfaces. It consists of a passenger domain secreted by the C-terminal transmembrane anchor domain (TM), and the passenger domain contains an N-terminal head, N-terminal stalk, C-terminal head (Chead), and C-terminal stalk (Cstalk). The Chead-Cstalk-TM fragment, which is conserved in many Acinetobacter TAAs, has by itself the head-stalk-anchor architecture of a complete TAA. Here, we show the crystal structure of the Chead-Cstalk fragment, AtaA_C-terminal passenger domain (CPSD), providing the first view of several conserved TAA domains. The YadA-like head (Ylhead) of the fragment is capped by a unique structure (headCap), composed of three β-hairpins and a connector motif; it also contains a head insert motif (HIM1) before its last inner β-strand. The headCap, Ylhead, and HIM1 integrally form a stable Chead structure. Some of the major domains of the CPSD fragment are inherently flexible and provide bending sites for the fiber between segments whose toughness is ensured by topological chain exchange and hydrophobic core formation inside the trimer. Thus, although adherence assays using in-frame deletion mutants revealed that the characteristic adhesive sites of AtaA reside in its N-terminal part, the flexibility and toughness of the CPSD part provide the resilience that enables the adhesive properties of the full-length fiber across a wide range of conditions.
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Affiliation(s)
- Kotaro Koiwai
- From the Department of Biotechnology, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan, the Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba 305-0801, Japan
| | - Marcus D Hartmann
- the Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany, and
| | - Dirk Linke
- the Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany, and the Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Andrei N Lupas
- the Department of Protein Evolution, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany, and
| | - Katsutoshi Hori
- From the Department of Biotechnology, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan,
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Abstract
The autotransporter and two-partner secretion (TPS) pathways are used by E. coli and many other Gram-negative bacteria to delivervirulence factors into the extracellular milieu.Autotransporters arecomprised of an N-terminal extracellular ("passenger") domain and a C-terminal β barrel domain ("β domain") that anchors the protein to the outer membrane and facilitates passenger domain secretion. In the TPS pathway, a secreted polypeptide ("exoprotein") is coordinately expressed with an outer membrane protein that serves as a dedicated transporter. Bothpathways are often grouped together under the heading "type V secretion" because they have many features in common and are used for the secretion of structurally related polypeptides, but it is likely that theyhave distinct evolutionary origins. Although it was proposed many years ago that autotransporterpassenger domains are transported across the outer membrane through a channel formed by the covalently linked β domain, there is increasing evidence that additional factors are involved in the translocation reaction. Furthermore, details of the mechanism of protein secretion through the TPS pathway are only beginning to emerge. In this chapter I discussour current understanding ofboth early and late steps in the biogenesis of polypeptides secreted through type V pathways and current modelsofthe mechanism of secretion.
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Chahales P, Thanassi DG. Structure, Function, and Assembly of Adhesive Organelles by Uropathogenic Bacteria. Microbiol Spectr 2015; 3:10.1128/microbiolspec.UTI-0018-2013. [PMID: 26542038 PMCID: PMC4638162 DOI: 10.1128/microbiolspec.uti-0018-2013] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 01/02/2023] Open
Abstract
Bacteria assemble a wide range of adhesive proteins, termed adhesins, to mediate binding to receptors and colonization of surfaces. For pathogenic bacteria, adhesins are critical for early stages of infection, allowing the bacteria to initiate contact with host cells, colonize different tissues, and establish a foothold within the host. The adhesins expressed by a pathogen are also critical for bacterial-bacterial interactions and the formation of bacterial communities, including biofilms. The ability to adhere to host tissues is particularly important for bacteria that colonize sites such as the urinary tract, where the flow of urine functions to maintain sterility by washing away non-adherent pathogens. Adhesins vary from monomeric proteins that are directly anchored to the bacterial surface to polymeric, hair-like fibers that extend out from the cell surface. These latter fibers are termed pili or fimbriae, and were among the first identified virulence factors of uropathogenic Escherichia coli. Studies since then have identified a range of both pilus and non-pilus adhesins that contribute to bacterial colonization of the urinary tract, and have revealed molecular details of the structures, assembly pathways, and functions of these adhesive organelles. In this review, we describe the different types of adhesins expressed by both Gram-negative and Gram-positive uropathogens, what is known about their structures, how they are assembled on the bacterial surface, and the functions of specific adhesins in the pathogenesis of urinary tract infections.
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Affiliation(s)
- Peter Chahales
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
| | - David G Thanassi
- Center for Infectious Diseases and Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794
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Qin W, Wang L, Lei L. New findings on the function and potential applications of the trimeric autotransporter adhesin. Antonie van Leeuwenhoek 2015; 108:1-14. [PMID: 26014492 DOI: 10.1007/s10482-015-0477-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/08/2015] [Indexed: 11/27/2022]
Abstract
Trimeric autotransporter adhesins (TAAs) are located on the surface of many pathogenic Gram-negative bacteria. TAAs belong to the autotransporter protein family and consist of three identical monomers. These obligate homotrimeric proteins are secreted through the bacterial type Vc secretion system and share a common molecular organization that each monomer consists of a N-terminal "passenger" domain and a C-terminal translocation domain. TAAs are important virulence factors that are involved in bacterial life cycle and participate in mediating infection, invasion, dissemination and evasion of host immune responses. TAAs have also proved to be useful for many applications, such as vaccines and disease biomarkers. We here mainly focused on new findings on bio-function and application of TAAs in addition to their common structure and secretion mechanisms.
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Affiliation(s)
- Wanhai Qin
- College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun, China,
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Sheibani-Tezerji R, Naveed M, Jehl MA, Sessitsch A, Rattei T, Mitter B. The genomes of closely related Pantoea ananatis maize seed endophytes having different effects on the host plant differ in secretion system genes and mobile genetic elements. Front Microbiol 2015; 6:440. [PMID: 26029184 PMCID: PMC4428218 DOI: 10.3389/fmicb.2015.00440] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/23/2015] [Indexed: 11/13/2022] Open
Abstract
The seed as a habitat for microorganisms is as yet under-explored and has quite distinct characteristics as compared to other vegetative plant tissues. In this study, we investigated three closely related P. ananatis strains (named S6, S7, and S8), which were isolated from maize seeds of healthy plants. Plant inoculation experiments revealed that each of these strains exhibited a different phenotype ranging from weak pathogenic (S7), commensal (S8), to a beneficial, growth-promoting effect (S6) in maize. We performed a comparative genomics analysis in order to find genetic determinants responsible for the differences observed. Recent studies provided exciting insight into the genetic drivers of niche adaption and functional diversification of the genus Pantoea. However, we report here for the first time on the analysis of P. ananatis strains colonizing the same ecological niche but showing distinct interaction strategies with the host plant. Our comparative analysis revealed that genomes of these three strains are highly similar. However, genomic differences in genes encoding protein secretion systems and putative effectors, and transposase/integrases/phage related genes could be observed.
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Affiliation(s)
- Raheleh Sheibani-Tezerji
- Bioresources Unit, Health and Environment Department, AIT Austrian Institute of Technology GmbHTulln, Austria
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of ViennaVienna, Austria
| | - Muhammad Naveed
- Bioresources Unit, Health and Environment Department, AIT Austrian Institute of Technology GmbHTulln, Austria
| | - Marc-André Jehl
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of ViennaVienna, Austria
| | - Angela Sessitsch
- Bioresources Unit, Health and Environment Department, AIT Austrian Institute of Technology GmbHTulln, Austria
| | - Thomas Rattei
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of ViennaVienna, Austria
| | - Birgit Mitter
- Bioresources Unit, Health and Environment Department, AIT Austrian Institute of Technology GmbHTulln, Austria
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Barlag B, Hensel M. The giant adhesin SiiE of Salmonella enterica. Molecules 2015; 20:1134-50. [PMID: 25587788 PMCID: PMC6272769 DOI: 10.3390/molecules20011134] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Accepted: 01/04/2015] [Indexed: 01/12/2023] Open
Abstract
Salmonella enterica is a Gram-negative, food-borne pathogen, which colonizes the intestinal tract and invades enterocytes. Invasion of polarized cells depends on the SPI1-encoded type III secretion system (T3SS) and the SPI4-encoded type I secretion system (T1SS). The substrate of this T1SS is the non-fimbrial giant adhesin SiiE. With a size of 595 kDa, SiiE is the largest protein of the Salmonella proteome and consists of 53 repetitive bacterial immunoglobulin (BIg) domains, each containing several conserved residues. As known for other T1SS substrates, such as E. coli HlyA, Ca2+ ions bound by conserved D residues within the BIg domains stabilize the protein and facilitate secretion. The adhesin SiiE mediates the first contact to the host cell and thereby positions the SPI1-T3SS to initiate the translocation of a cocktail of effector proteins. This leads to actin remodeling, membrane ruffle formation and bacterial internalization. SiiE binds to host cell apical membranes in a lectin-like manner. GlcNAc and α2–3 linked sialic acid-containing structures are ligands of SiiE. Since SiiE shows repetitive domain architecture, we propose a zipper-like binding mediated by each individual BIg domain. In this review, we discuss the characteristics of the SPI4-T1SS and the giant adhesin SiiE.
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Affiliation(s)
- Britta Barlag
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, Osnabrück 49076, Germany.
| | - Michael Hensel
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, Osnabrück 49076, Germany.
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Bassler J, Hernandez Alvarez B, Hartmann MD, Lupas AN. A domain dictionary of trimeric autotransporter adhesins. Int J Med Microbiol 2014; 305:265-75. [PMID: 25583454 DOI: 10.1016/j.ijmm.2014.12.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Trimeric autotransporter adhesins (TAAs) are modular, highly repetitive outer membrane proteins that mediate adhesion to external surfaces in many Gram-negative bacteria. In recent years, several TAAs have been investigated in considerable detail, also at the structural level. However, in their vast majority, putative TAAs in prokaryotic genomes remain poorly annotated, due to their sequence diversity and changeable domain architecture. In order to achieve an automated annotation of these proteins that is both detailed and accurate we have taken a domain dictionary approach, in which we identify recurrent domains by sequence comparisons, produce bioinformatic descriptors for each domain type, and connect these to structural information where available. We implemented this approach in a web-based platform, daTAA, in 2008 and demonstrated its applicability by reconstructing the complete fiber structure of a TAA conserved in enterobacteria. Here we review current knowledge on the domain structure of TAAs.
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Affiliation(s)
- Jens Bassler
- Department of Protein Evolution, Max-Planck-Institute for Developmental Biology, Spemannstr. 35, 72076 Tuebingen, Germany
| | - Birte Hernandez Alvarez
- Department of Protein Evolution, Max-Planck-Institute for Developmental Biology, Spemannstr. 35, 72076 Tuebingen, Germany
| | - Marcus D Hartmann
- Department of Protein Evolution, Max-Planck-Institute for Developmental Biology, Spemannstr. 35, 72076 Tuebingen, Germany
| | - Andrei N Lupas
- Department of Protein Evolution, Max-Planck-Institute for Developmental Biology, Spemannstr. 35, 72076 Tuebingen, Germany.
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Haemophilus influenzae surface fibril (Hsf) is a unique twisted hairpin-like trimeric autotransporter. Int J Med Microbiol 2014; 305:27-37. [PMID: 25465160 DOI: 10.1016/j.ijmm.2014.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 10/08/2014] [Accepted: 10/18/2014] [Indexed: 11/21/2022] Open
Abstract
The Haemophilus surface fibril (Hsf) is an extraordinary large (2413 amino acids) trimeric autotransporter, present in all encapsulated Haemophilus influenzae. It contributes to virulence by directly functioning as an adhesin. Furthermore, Hsf recruits the host factor vitronectin thereby inhibiting the host innate immune response resulting in enhanced survival in serum. Here we observed by electron microscopy that Hsf appears as an 100 nm long fibril at the bacterial surface albeit the length is approximately 200 nm according to a bioinformatics based model. To unveil this discrepancy, we denaturated Hsf at the surface of Hib by using guanidine hydrochloride (GuHCl). Partial denaturation induced in the presence of GuHCl unfolded the Hsf molecules, and resulted in an increased length of fibres in comparison to the native trimeric form. Importantly, our findings were also verified by E. coli expressing Hsf at its surface. In addition, a set of Hsf-specific peptide antibodies also indicated that the N-terminal of Hsf is located near the C-terminal at the base of the fibril. Taken together, our results demonstrated that Hsf is not a straight molecule but is folded and doubled over. This is the first report that provides the unique structural features of the trimeric autotransporter Hsf.
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Lafontaine ER, Balder R, Michel F, Hogan RJ. Characterization of an autotransporter adhesin protein shared by Burkholderia mallei and Burkholderia pseudomallei. BMC Microbiol 2014; 14:92. [PMID: 24731253 PMCID: PMC4021183 DOI: 10.1186/1471-2180-14-92] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 04/08/2014] [Indexed: 12/21/2022] Open
Abstract
Background Autotransporters form a large family of outer membrane proteins specifying diverse biological traits of Gram-negative bacteria. In this study, we report the identification and characterization of a novel autotransporter gene product of Burkholderia mallei (locus tag BMA1027 in strain ATCC 23344). Results Database searches identified the gene in at least seven B. mallei isolates and the encoded proteins were found to be 84% identical. Inactivation of the gene encoding the autotransporter in the genome of strain ATCC 23344 substantially reduces adherence to monolayers of HEp-2 laryngeal cells and A549 type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, expression of the autotransporter on the surface of recombinant E. coli bacteria increases adherence to these cell types by 5–7 fold. The gene specifying the autotransporter was identified in the genome of 29 B. pseudomallei isolates and disruption of the gene in strain DD503 reduced adherence to NHBE cultures by 61%. Unlike B. mallei, the mutation did not impair binding of B. pseudomallei to A549 or HEp-2 cells. Analysis of sera from mice infected via the aerosol route with B. mallei and B. pseudomallei revealed that animals inoculated with as few as 10 organisms produce antibodies against the autotransporter, therefore indicating expression in vivo. Conclusions Our data demonstrate that we have identified an autotransporter protein common to the pathogenic species B. mallei and B. pseudomallei which mediates adherence to respiratory epithelial cells and is expressed in vivo during the course of aerosol infection.
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Affiliation(s)
- Eric R Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, 30602 Athens, GA, USA.
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Solar M, Buehler MJ. Tensile deformation and failure of amyloid and amyloid-like protein fibrils. NANOTECHNOLOGY 2014; 25:105703. [PMID: 24532127 DOI: 10.1088/0957-4484/25/10/105703] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Here we report a series of full atomistic molecular dynamics simulations of six amyloid or amyloid-like protein fibrils in order to systematically understand the effect of different secondary structure motifs on the mechanical tensile and failure response of cross-β protein fibrils. We find a similar failure behavior across the six structures; an initial failure event occurs at small strains involving cooperative rupture of a group of hydrogen bonds, followed by a slow one-by-one hydrogen bond rupture process as the remaining β-sheets peel off with very low applied stress. We also find that the ultimate tensile strength of the protein fibrils investigated scales directly with the number of hydrogen bonds per unit area which break in the initial rupture event. Our results provide insights into structure-property relationships in protein fibrils important for disease and engineering applications and lay the groundwork for the development of materials selection criteria for the design of de novo amyloid-based functional biomaterials.
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Affiliation(s)
- Max Solar
- Laboratory for Atomistic and Molecular Mechanics (LAMM), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA. Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, USA
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The Haemophilus cryptic genospecies Cha adhesin has at least two variants that differ in host cell binding, bacterial aggregation, and biofilm formation properties. J Bacteriol 2014; 196:1780-8. [PMID: 24584499 DOI: 10.1128/jb.01409-13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Haemophilus cryptic genospecies (HCG) causes genital tract infections in pregnant and postpartum women and respiratory infections in neonates. The major surface adhesin in HCG is called Cha, which mediates bacterial adherence to cultured human epithelial cells. In this study, we report that there are two antigenically distinct variants of Cha, dubbed Cha1 and Cha2. These variants are encoded by the same genetic locus in diverse strains and have nearly identical N-terminal export and C-terminal surface anchoring domains but significantly different internal adhesive domains. Based on the comparison of derivatives of a laboratory strain of Haemophilus influenzae expressing either surface-associated Cha1 or surface-associated Cha2, Cha1 mediates a higher level of adherence to cultured human epithelial cells and Cha2 mediates a higher level of adherence to abiotic surfaces. We hypothesize that variation in the Cha1 and Cha2 internal region results in changes in binding specificity or binding affinity and may be associated with adaptation to different host environments during colonization and disease.
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Wagner C, Barlag B, Gerlach RG, Deiwick J, Hensel M. TheSalmonella entericagiant adhesin SiiE binds to polarized epithelial cells in a lectin-like manner. Cell Microbiol 2014; 16:962-75. [DOI: 10.1111/cmi.12253] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 12/04/2013] [Accepted: 12/10/2013] [Indexed: 12/14/2022]
Affiliation(s)
- Carolin Wagner
- Abteilung Mikrobiologie; Universität Osnabrück; Osnabrück Germany
- Mikrobiologisches Institut; Universitätsklinikum Erlangen; Erlangen Germany
| | - Britta Barlag
- Abteilung Mikrobiologie; Universität Osnabrück; Osnabrück Germany
| | | | - Jörg Deiwick
- Abteilung Mikrobiologie; Universität Osnabrück; Osnabrück Germany
| | - Michael Hensel
- Abteilung Mikrobiologie; Universität Osnabrück; Osnabrück Germany
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Chagnot C, Zorgani MA, Astruc T, Desvaux M. Proteinaceous determinants of surface colonization in bacteria: bacterial adhesion and biofilm formation from a protein secretion perspective. Front Microbiol 2013; 4:303. [PMID: 24133488 PMCID: PMC3796261 DOI: 10.3389/fmicb.2013.00303] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 09/22/2013] [Indexed: 01/30/2023] Open
Abstract
Bacterial colonization of biotic or abiotic surfaces results from two quite distinct physiological processes, namely bacterial adhesion and biofilm formation. Broadly speaking, a biofilm is defined as the sessile development of microbial cells. Biofilm formation arises following bacterial adhesion but not all single bacterial cells adhering reversibly or irreversibly engage inexorably into a sessile mode of growth. Among molecular determinants promoting bacterial colonization, surface proteins are the most functionally diverse active components. To be present on the bacterial cell surface, though, a protein must be secreted in the first place. Considering the close association of secreted proteins with their cognate secretion systems, the secretome (which refers both to the secretion systems and their protein substrates) is a key concept to apprehend the protein secretion and related physiological functions. The protein secretion systems are here considered in light of the differences in the cell-envelope architecture between diderm-LPS (archetypal Gram-negative), monoderm (archetypal Gram-positive) and diderm-mycolate (archetypal acid-fast) bacteria. Besides, their cognate secreted proteins engaged in the bacterial colonization process are regarded from single protein to supramolecular protein structure as well as the non-classical protein secretion. This state-of-the-art on the complement of the secretome (the secretion systems and their cognate effectors) involved in the surface colonization process in diderm-LPS and monoderm bacteria paves the way for future research directions in the field.
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Affiliation(s)
- Caroline Chagnot
- UR454 Microbiologie, INRA Saint-Genès Champanelle, France ; UR370 Qualité des Produits Animaux, INRA Saint-Genès Champanelle, France
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Kumar S, Puniya BL, Parween S, Nahar P, Ramachandran S. Identification of novel adhesins of M. tuberculosis H37Rv using integrated approach of multiple computational algorithms and experimental analysis. PLoS One 2013; 8:e69790. [PMID: 23922800 PMCID: PMC3726780 DOI: 10.1371/journal.pone.0069790] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/18/2013] [Indexed: 01/24/2023] Open
Abstract
Pathogenic bacteria interacting with eukaryotic host express adhesins on their surface. These adhesins aid in bacterial attachment to the host cell receptors during colonization. A few adhesins such as Heparin binding hemagglutinin adhesin (HBHA), Apa, Malate Synthase of M. tuberculosis have been identified using specific experimental interaction models based on the biological knowledge of the pathogen. In the present work, we carried out computational screening for adhesins of M. tuberculosis. We used an integrated computational approach using SPAAN for predicting adhesins, PSORTb, SubLoc and LocTree for extracellular localization, and BLAST for verifying non-similarity to human proteins. These steps are among the first of reverse vaccinology. Multiple claims and attacks from different algorithms were processed through argumentative approach. Additional filtration criteria included selection for proteins with low molecular weights and absence of literature reports. We examined binding potential of the selected proteins using an image based ELISA. The protein Rv2599 (membrane protein) binds to human fibronectin, laminin and collagen. Rv3717 (N-acetylmuramoyl-L-alanine amidase) and Rv0309 (L,D-transpeptidase) bind to fibronectin and laminin. We report Rv2599 (membrane protein), Rv0309 and Rv3717 as novel adhesins of M. tuberculosis H37Rv. Our results expand the number of known adhesins of M. tuberculosis and suggest their regulated expression in different stages.
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Affiliation(s)
- Sanjiv Kumar
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Bhanwar Lal Puniya
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Shahila Parween
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Pradip Nahar
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
| | - Srinivasan Ramachandran
- Functional Genomics Unit, Council of Scientific and Industrial Research -Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, India
- * E-mail:
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Hao G, Boyle M, Zhou L, Duan Y. The intracellular citrus huanglongbing bacterium, 'Candidatus Liberibacter asiaticus' encodes two novel autotransporters. PLoS One 2013; 8:e68921. [PMID: 23874813 PMCID: PMC3708911 DOI: 10.1371/journal.pone.0068921] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 06/04/2013] [Indexed: 01/09/2023] Open
Abstract
Proteins secreted by the type V secretion system (T5SS), known as autotransporters, are large extracellular virulence proteins localized to the bacterial poles. In this study, we characterized two novel autotransporter proteins of 'Candidatus Liberibacter asiaticus' (Las), and redesignated them as LasAI and LasAII in lieu of the previous names HyvI and HyvII. As a phloem-limited, intracellular bacterial pathogen, Las has a significantly reduced genome and causes huanglongbing (HLB), a devastating disease of citrus worldwide. Bioinformatic analyses revealed that LasAI and LasAII share the structural features of an autotransporter family containing large repeats of a passenger domain and a unique C-terminal translocator domain. When fused to the GFP gene and expressed in E. coli, the LasAI C-terminus and the full length LasAII were localized to the bacterial poles, similar to other members of autotransporter family. Despite the absence of a typical signal peptide, LasAI was found to localize at the cell surface by immuno-dot blot using a monoclonal antibody against the partial LasAI protein. Its surface localization was also confirmed by the removal of the LasAI antigen using a proteinase K treatment of the intact bacterial cells. When co-inoculated with a P19 gene silencing suppressor and transiently expressed in tobacco leaves, the GFP-LasAI translocator targeted to the mitochondria. This is the first report that Las encodes novel autotransporters that target to mitochondria when expressed in the plants. These findings may lead to a better understanding of the pathogenesis of this intracellular bacterium.
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Affiliation(s)
- Guixia Hao
- United States Horticultural Research Laboratory, United States Department of Agriculture-Agriculture Research Service, Fort Pierce, Florida, United States of America
| | - Michael Boyle
- Smithsonian Marine Station, Fort Pierce, Florida, United States of America
| | - Lijuan Zhou
- United States Horticultural Research Laboratory, United States Department of Agriculture-Agriculture Research Service, Fort Pierce, Florida, United States of America
| | - Yongping Duan
- United States Horticultural Research Laboratory, United States Department of Agriculture-Agriculture Research Service, Fort Pierce, Florida, United States of America
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