1
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Johnson AO, Shipman BM, Hunt BC, Learman BS, Brauer AL, Zhou SP, Hageman Blair R, De Nisco NJ, Armbruster CE. Function and contribution of two putative Enterococcus faecalis glycosaminoglycan degrading enzymes to bacteremia and catheter-associated urinary tract infection. Infect Immun 2024; 92:e0019924. [PMID: 38842305 DOI: 10.1128/iai.00199-24] [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: 05/04/2024] [Accepted: 05/13/2024] [Indexed: 06/07/2024] Open
Abstract
Enterococcus faecalis is a common cause of healthcare-acquired bloodstream infections and catheter-associated urinary tract infections (CAUTIs) in both adults and children. Treatment of E. faecalis infection is frequently complicated by multi-drug resistance. Based on protein homology, E. faecalis encodes two putative hyaluronidases, EF3023 (HylA) and EF0818 (HylB). In other Gram-positive pathogens, hyaluronidases have been shown to contribute to tissue damage and immune evasion, but the function in E. faecalis has yet to be explored. Here, we show that both hylA and hylB contribute to E. faecalis pathogenesis. In a CAUTI model, ΔhylA exhibited defects in bladder colonization and dissemination to the bloodstream, and ΔhylB exhibited a defect in kidney colonization. Furthermore, a ΔhylAΔhylB double mutant exhibited a severe colonization defect in a model of bacteremia while the single mutants colonized to a similar level as the wild-type strain, suggesting potential functional redundancy within the bloodstream. We next examined enzymatic activity, and demonstrate that HylB is capable of digesting both hyaluronic acid (HA) and chondroitin sulfate in vitro, while HylA exhibits only a very modest activity against heparin. Importantly, HA degradation by HylB provided a modest increase in cell density during the stationary phase and also contributed to dampening of lipopolysaccharide-mediated NF-κB activation. Overall, these data demonstrate that glycosaminoglycan degradation is important for E. faecalis pathogenesis in the urinary tract and during bloodstream infection.
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Affiliation(s)
- Alexandra O Johnson
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Braden M Shipman
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Benjamin C Hunt
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Brian S Learman
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Aimee L Brauer
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Serena P Zhou
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
| | - Rachael Hageman Blair
- Department of Biostatistics, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, New York, USA
| | - Nicole J De Nisco
- Department of Biological Sciences, University of Texas at Dallas, Richardson, Texas, USA
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chelsie E Armbruster
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
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2
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Snell A, Manias DA, Elbehery RR, Dunny GM, Willett JLE. Arginine impacts aggregation, biofilm formation, and antibiotic susceptibility in Enterococcus faecalis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.30.596650. [PMID: 38853917 PMCID: PMC11160706 DOI: 10.1101/2024.05.30.596650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Enterococcus faecalis is a commensal bacterium in the gastrointestinal tract (GIT) of humans and other organisms. E. faecalis also causes infections in root canals, wounds, the urinary tract, and on heart valves. E. faecalis metabolizes arginine through the arginine deiminase (ADI) pathway, which converts arginine to ornithine and releases ATP, ammonia, and CO2. E. faecalis arginine metabolism also affects virulence of other pathogens during co-culture. E. faecalis may encounter elevated levels of arginine in the GIT or the oral cavity, where arginine is used as a dental therapeutic. Little is known about how E. faecalis responds to growth in arginine in the absence of other bacteria. To address this, we used RNAseq and additional assays to measure growth, gene expression, and biofilm formation in E. faecalis OG1RF grown in arginine. We demonstrate that arginine decreases E. faecalis biofilm production and causes widespread differential expression of genes related to metabolism, quorum sensing, and polysaccharide synthesis. Growth in arginine also increases aggregation of E. faecalis and promotes decreased susceptibility to the antibiotics ampicillin and ceftriaxone. This work provides a platform for understanding of how the presence of arginine in biological niches affects E. faecalis physiology and virulence of surrounding microbes.
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Affiliation(s)
- Alex Snell
- University of Minnesota Medical School, Minneapolis, MN, 55455
| | - Dawn A. Manias
- University of Minnesota Medical School, Minneapolis, MN, 55455
| | | | - Gary M. Dunny
- University of Minnesota Medical School, Minneapolis, MN, 55455
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3
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Johnson AO, Shipman BM, Hunt BC, Learman BS, Brauer AL, Zhou SP, Blair RH, De Nisco NJ, Armbruster CE. Function and contribution of two putative Enterococcus faecalis glycosaminoglycan degrading enzymes to bacteremia and catheter-associated urinary tract infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593205. [PMID: 38766094 PMCID: PMC11100720 DOI: 10.1101/2024.05.08.593205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Enterococcus faecalis is a common cause of healthcare acquired bloodstream infections and catheter associated urinary tract infections (CAUTI) in both adults and children. Treatment of E. faecalis infection is frequently complicated by multi-drug resistance. Based on protein homology, E. faecalis encodes two putative hyaluronidases, EF3023 (HylA) and EF0818 (HylB). In other Gram-positive pathogens, hyaluronidases have been shown to contribute to tissue damage and immune evasion, but function in E. faecalis has yet to be explored. Here, we show that both hylA and hylB contribute to E. faecalis pathogenesis. In a CAUTI model, Δ hylA exhibited defects in bladder colonization and dissemination to the bloodstream, and Δ hylB exhibited a defect in kidney colonization. Furthermore, a Δ hylA Δ hylB double mutant exhibited a severe colonization defect in a model of bacteremia while the single mutants colonized to a similar level as the wild-type strain, suggesting potential functional redundancy within the bloodstream. We next examined enzymatic activity, and demonstrate that HylB is capable of digesting both HA and CS in vitro while HylA exhibits only a very modest activity against heparin. Importantly, HA degradation by HylB provided a modest increase in cell density during stationary phase and also contributed to dampening of LPS-mediated NF-Bκ activation. Overall, these data demonstrate that glycosaminoglycan degradation is important for E. faecalis pathogenesis in the urinary tract and during bloodstream infection.
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4
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Salamaga B, Turner RD, Elsarmane F, Galley NF, Kulakauskas S, Mesnage S. A moonlighting role for LysM peptidoglycan binding domains underpins Enterococcus faecalis daughter cell separation. Commun Biol 2023; 6:428. [PMID: 37072531 PMCID: PMC10113225 DOI: 10.1038/s42003-023-04808-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/04/2023] [Indexed: 04/20/2023] Open
Abstract
Control of cell size and morphology is of paramount importance for bacterial fitness. In the opportunistic pathogen Enterococcus faecalis, the formation of diplococci and short cell chains facilitates innate immune evasion and dissemination in the host. Minimisation of cell chain size relies on the activity of a peptidoglycan hydrolase called AtlA, dedicated to septum cleavage. To prevent autolysis, AtlA activity is tightly controlled, both temporally and spatially. Here, we show that the restricted localization of AtlA at the septum occurs via an unexpected mechanism. We demonstrate that the C-terminal LysM domain that allows the enzyme to bind peptidoglycan is essential to target this enzyme to the septum inside the cell before its translocation across the membrane. We identify a membrane-bound cytoplasmic protein partner (called AdmA) involved in the recruitment of AtlA via its LysM domains. This work reveals a moonlighting role for LysM domains, and a mechanism evolved to restrict the subcellular localization of a potentially lethal autolysin to its site of action.
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Affiliation(s)
| | - Robert D Turner
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Fathe Elsarmane
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
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5
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Kwan JMC, Qiao Y. Mechanistic Insights into the Activities of Major Families of Enzymes in Bacterial Peptidoglycan Assembly and Breakdown. Chembiochem 2023; 24:e202200693. [PMID: 36715567 DOI: 10.1002/cbic.202200693] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
Serving as an exoskeletal scaffold, peptidoglycan is a polymeric macromolecule that is essential and conserved across all bacteria, yet is absent in mammalian cells; this has made bacterial peptidoglycan a well-established excellent antibiotic target. In addition, soluble peptidoglycan fragments derived from bacteria are increasingly recognised as key signalling molecules in mediating diverse intra- and inter-species communication in nature, including in gut microbiota-host crosstalk. Each bacterial species encodes multiple redundant enzymes for key enzymatic activities involved in peptidoglycan assembly and breakdown. In this review, we discuss recent findings on the biochemical activities of major peptidoglycan enzymes, including peptidoglycan glycosyltransferases (PGT) and transpeptidases (TPs) in the final stage of peptidoglycan assembly, as well as peptidoglycan glycosidases, lytic transglycosylase (LTs), amidases, endopeptidases (EPs) and carboxypeptidases (CPs) in peptidoglycan turnover and metabolism. Biochemical characterisation of these enzymes provides valuable insights into their substrate specificity, regulation mechanisms and potential modes of inhibition.
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Affiliation(s)
- Jeric Mun Chung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), 21 Nanyang Link, Singapore, 637371, Singapore.,LKC School of Medicine, Nanyang Technological University (NTU) Singapore, 11 Mandalay Road, Singapore, Singapore, 208232, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), Singapore, 21 Nanyang Link, Singapore, 637371, Singapore
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6
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Choo PY, Wang CY, VanNieuwenhze MS, Kline KA. Spatial and temporal localization of cell wall associated pili in Enterococcus faecalis. Mol Microbiol 2023; 119:1-18. [PMID: 36420961 PMCID: PMC10107303 DOI: 10.1111/mmi.15008] [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: 05/16/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022]
Abstract
Enterococcus faecalis virulence requires cell wall-associated proteins, including the sortase-assembled endocarditis and biofilm associated pilus (Ebp), important for biofilm formation in vitro and in vivo. The current paradigm for sortase-assembled pilus biogenesis in Gram-positive bacteria is that sortases attach substrates to lipid II peptidoglycan (PG) precursors, prior to their incorporation into the growing cell wall. Contrary to prevailing dogma, by following the distribution of Ebp and PG throughout the E. faecalis cell cycle, we found that cell surface Ebp do not co-localize with newly synthesized PG. Instead, surface-exposed Ebp are localized to the older cell hemisphere and excluded from sites of new PG synthesis at the septum. Moreover, Ebp deposition on the younger hemisphere of the E. faecalis diplococcus appear as foci adjacent to the nascent septum. We propose a new model whereby sortase substrate deposition can occur on older PG rather than at sites of new cell wall synthesis. Consistent with this model, we demonstrate that sequestering lipid II to block PG synthesis via ramoplanin, does not impact new Ebp deposition at the cell surface. These data support an alternative paradigm for sortase substrate deposition in E. faecalis, in which Ebp are anchored directly onto uncrosslinked cell wall, independent of new PG synthesis.
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Affiliation(s)
- Pei Yi Choo
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Charles Y Wang
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | | | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
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7
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Zhong X, Ma J, Bai Q, Zhu Y, Zhang Y, Gu Q, Pan Z, Liu G, Wu Z, Yao H. Identification of the RNA-binding domain-containing protein RbpA that acts as a global regulator of the pathogenicity of Streptococcus suis serotype 2. Virulence 2022; 13:1304-1314. [PMID: 35903019 PMCID: PMC9341378 DOI: 10.1080/21505594.2022.2103233] [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] [Indexed: 11/12/2022] Open
Abstract
Streptococcus suis serotype 2 (SS2), an emerging zoonotic pathogen, causes swine diseases and human cases of streptococcal toxic shock syndrome. RNA-binding proteins (RBPs) can modulate gene expression through post-transcriptional regulation. In this study, we identified an RBP harbouring an S1 domain, named RbpA, which facilitated SS2 adhesion to host epithelial cells and contributed to bacterial pathogenicity. Comparative proteomic analysis identified 145 proteins that were expressed differentially between ΔrbpA strain and wild-type strain, including several virulence-associated factors, such as the extracellular protein factor (EF), SrtF pilus, IgA1 protease, SBP2 pilus, and peptidoglycan-binding LysM’ proteins. The mechanisms underlying the regulatory effects of RbpA on their encoding genes were explored, and it was found that RbpA regulates gene expression through diverse mechanisms, including post-transcriptional regulation, and thus acts as a global regulator. These results partly reveal the pathogenic mechanism mediated by RbpA, improving our understanding of the regulatory systems of S. suis and providing new insights into bacterial pathogenicity.
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Affiliation(s)
- Xiaojun Zhong
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A & F University, Hangzhou, China
| | - Jiale Ma
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Qiankun Bai
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Yinchu Zhu
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,Institute of Animal Husbandry and Veterinary Sciences, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Yue Zhang
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.,College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Qibing Gu
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zihao Pan
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Guangjin Liu
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zongfu Wu
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Huochun Yao
- OIE Reference Lab for Swine Streptococcosis, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
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8
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Davis JL, Hounslow AM, Baxter NJ, Mesnage S, Williamson MP. 1H, 13C, and 15N resonance assignments of a conserved putative cell wall binding domain from Enterococcus faecalis. BIOMOLECULAR NMR ASSIGNMENTS 2022; 16:247-251. [PMID: 35665899 PMCID: PMC9510096 DOI: 10.1007/s12104-022-10087-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Enterococcus faecalis is a major causative agent of hospital acquired infections. The ability of E. faecalis to evade the host immune system is essential during pathogenesis, which has been shown to be dependent on the complete separation of daughter cells by peptidoglycan hydrolases. AtlE is a peptidoglycan hydrolase which is predicted to bind to the cell wall of E. faecalis, via six C-terminal repeat sequences. Here, we report the near complete assignment of one of these six repeats, as well as the predicted backbone structure and dynamics. This data will provide a platform for future NMR studies to explore the ligand recognition motif of AtlE and help to uncover its potential role in E. faecalis virulence.
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Affiliation(s)
- Jessica L Davis
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, UK
| | - Andrea M Hounslow
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, UK
| | - Nicola J Baxter
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, UK
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, UK
| | - Mike P Williamson
- School of Biosciences, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, UK.
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9
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Venkateswaran P, Lakshmanan PM, Muthukrishnan S, Bhagavathi H, Vasudevan S, Neelakantan P, Solomon AP. Hidden agenda of Enterococcus faecalis lifestyle transition: planktonic to sessile state. Future Microbiol 2022; 17:1051-1069. [PMID: 35899477 DOI: 10.2217/fmb-2021-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enterococcus faecalis, a human gastrointestinal tract commensal, is known to cause nosocomial infections. Interestingly, the pathogen's host colonization and persistent infections are possibly linked to its lifestyle changes from planktonic to sessile state. Also, the multidrug resistance and survival fitness acquired in the sessile stage of E. faecalis has challenged treatment regimes. This situation exists because of the critical role played by several root genes and their molecular branches, which are part of quorum sensing, aggregation substance, surface adhesions, stress-related response and sex pheromones in the sessile state. It is therefore imperative to decode the hidden agenda of E. faecalis and understand the significant factors influencing biofilm formation. This would, in turn, augment the development of novel strategies to tackle E. faecalis infections.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Priya M Lakshmanan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sudhiksha Muthukrishnan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Hema Bhagavathi
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | | | - Adline P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
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10
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Roig-Zamboni V, Barelier S, Dixon R, Galley NF, Ghanem A, Nguyen QP, Cahuzac H, Salamaga B, Davis PJ, Bourne Y, Mesnage S, Vincent F. Molecular basis for substrate recognition and septum cleavage by AtlA, the major N-acetylglucosaminidase of Enterococcus faecalis. J Biol Chem 2022; 298:101915. [PMID: 35398351 PMCID: PMC9108991 DOI: 10.1016/j.jbc.2022.101915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/26/2022] Open
Abstract
The cleavage of septal peptidoglycan at the end of cell division facilitates the separation of the two daughter cells. The hydrolases involved in this process (called autolysins) are potentially lethal enzymes that can cause cell death; their activity, therefore, must be tightly controlled during cell growth. In Enterococcus faecalis, the N-acetylglucosaminidase AtlA plays a predominant role in cell separation. atlA mutants form long cell chains and are significantly less virulent in the zebrafish model of infection. The attenuated virulence of atlA mutants is underpinned by a limited dissemination of bacterial chains in the host organism and a more efficient uptake by phagocytes that clear the infection. AtlA has structural homologs in other important pathogens, such as Listeria monocytogenes and Salmonella typhimurium, and therefore represents an attractive model to design new inhibitors of bacterial pathogenesis. Here, we provide a 1.45 Å crystal structure of the E. faecalis AtlA catalytic domain that reveals a closed conformation of a conserved β-hairpin and a complex network of hydrogen bonds that bring two catalytic residues to the ideal distance for an inverting mechanism. Based on the model of the AtlA-substrate complex, we identify key residues critical for substrate recognition and septum cleavage during bacterial growth. We propose that this work will provide useful information for the rational design of specific inhibitors targeting this enterococcal virulence factor and its orthologs in other pathogens.
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Affiliation(s)
| | | | - Robert Dixon
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Amani Ghanem
- CNRS, Aix Marseille University, AFMB, Marseille, France
| | | | - Héloize Cahuzac
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | | | - Peter J Davis
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Yves Bourne
- CNRS, Aix Marseille University, AFMB, Marseille, France
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom.
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11
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Vázquez R, Seoane-Blanco M, Rivero-Buceta V, Ruiz S, van Raaij MJ, García P. Monomodular Pseudomonas aeruginosa phage JG004 lysozyme (Pae87) contains a bacterial surface-active antimicrobial peptide-like region and a possible substrate-binding subdomain. ACTA CRYSTALLOGRAPHICA SECTION D STRUCTURAL BIOLOGY 2022; 78:435-454. [PMID: 35362467 PMCID: PMC8972805 DOI: 10.1107/s2059798322000936] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/27/2022] [Indexed: 11/10/2022]
Abstract
The structure of the monomodular Pseudomonas aeruginosa bacteriophage JG004 lysin Pae87 is presented and investigated in relation to repurposing its function as an antimicrobial agent. The structure with its peptidoglycan ligand revealed a possible cell-wall-binding region. A C-terminal antimicrobial peptide-like region is shown to be important for disrupting the bacterial cell wall. Phage lysins are a source of novel antimicrobials to tackle the bacterial antibiotic-resistance crisis. The engineering of phage lysins is being explored as a game-changing technological strategy to introduce a more precise approach in the way in which antimicrobial therapy is applied. Such engineering efforts will benefit from a better understanding of lysin structure and function. In this work, the antimicrobial activity of the endolysin from Pseudomonas aeruginosa phage JG004, termed Pae87, has been characterized. This lysin had previously been identified as an antimicrobial agent candidate that is able to interact with the Gram-negative surface and disrupt it. Further evidence is provided here based on a structural and biochemical study. A high-resolution crystal structure of Pae87 complexed with a peptidoglycan fragment showed a separate substrate-binding region within the catalytic domain, 18 Å away from the catalytic site and located on the opposite side of the lysin molecule. This substrate-binding region was conserved among phylogenetically related lysins lacking an additional cell-wall-binding domain, but not among those containing such a module. Two glutamic acids were identified to be relevant for the peptidoglycan-degradation activity, although the antimicrobial activity of Pae87 was seemingly unrelated. In contrast, an antimicrobial peptide-like region within the Pae87 C-terminus, named P87, was found to be able to actively disturb the outer membrane and display antibacterial activity by itself. Therefore, an antimicrobial mechanism for Pae87 is proposed in which the P87 peptide plays the role of binding to the outer membrane and disrupting the cell-wall function, either with or without the participation of the catalytic activity of Pae87.
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12
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PplD is a de-N-acetylase of the cell wall linkage unit of streptococcal rhamnopolysaccharides. Nat Commun 2022; 13:590. [PMID: 35105886 PMCID: PMC8807736 DOI: 10.1038/s41467-022-28257-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 01/07/2022] [Indexed: 02/06/2023] Open
Abstract
The cell wall of the human bacterial pathogen Group A Streptococcus (GAS) consists of peptidoglycan decorated with the Lancefield group A carbohydrate (GAC). GAC is a promising target for the development of GAS vaccines. In this study, employing chemical, compositional, and NMR methods, we show that GAC is attached to peptidoglycan via glucosamine 1-phosphate. This structural feature makes the GAC-peptidoglycan linkage highly sensitive to cleavage by nitrous acid and resistant to mild acid conditions. Using this characteristic of the GAS cell wall, we identify PplD as a protein required for deacetylation of linkage N-acetylglucosamine (GlcNAc). X-ray structural analysis indicates that PplD performs catalysis via a modified acid/base mechanism. Genetic surveys in silico together with functional analysis indicate that PplD homologs deacetylate the polysaccharide linkage in many streptococcal species. We further demonstrate that introduction of positive charges to the cell wall by GlcNAc deacetylation protects GAS against host cationic antimicrobial proteins.
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13
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López-Arvizu A, Rocha-Mendoza D, Farrés A, Ponce-Alquicira E, García-Cano I. Improved antimicrobial spectrum of the N-acetylmuramoyl-L-alanine amidase from Latilactobacillus sakei upon LysM domain deletion. World J Microbiol Biotechnol 2021; 37:196. [PMID: 34654973 DOI: 10.1007/s11274-021-03169-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 10/06/2021] [Indexed: 10/20/2022]
Abstract
The gene encoding N-acetylmuramoyl-L-alanine amidase in Latilactobacillus sakei isolated from a fermented meat product was cloned in two forms: its complete sequence (AmiC) and a truncated sequence without one of its anchoring LysM domains (AmiLysM4). The objective of this work was to evaluate the effect of LysM domain deletion on antibacterial activity as well the biochemical characterization of each recombinant protein. AmiC and AmiLysM4 were expressed in Escherichia coli BL21. Using a zymography method, two bands with lytic activity were observed, which were confirmed by LC-MS/MS analysis, with molecular masses of 71 kDa (AmiC) and 66 kDa (AmiLysM4). The recombinant proteins were active against Listeria innocua and Staphylococcus aureus strains. The inhibitory spectrum of AmiLysM4 was broader than AmiC as it showed inhibition of Leuconostoc mesenteroides and Weissella viridescens, both microorganisms associated with food decomposition. Optimal temperature and pH values were determined for both proteins using L-alanine-p-nitroanilide hydrochloride as a substrate for N-acetylmuramoyl-L-alanine amidase activity. Both proteins showed similar maximum activity values for pH (8) and temperature (50 °C). Furthermore, structural predictions did not show differences for the catalytic region, but differences were found for the region called 2dom-AmiLysM4, which includes 4 of the 5 LysM domains. Therefore, modification of the LysM domain offers new tools for the development of novel food biopreservatives.
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Affiliation(s)
- Adriana López-Arvizu
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Unidad Iztapalapa, Mexico, México
| | - Diana Rocha-Mendoza
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA
| | - Amelia Farrés
- Departamento de Alimentos y Biotecnología, Facultad de Química UNAM, Mexico, México
| | - Edith Ponce-Alquicira
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Unidad Iztapalapa, Mexico, México.
| | - Israel García-Cano
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Unidad Iztapalapa, Mexico, México. .,Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA.
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14
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Patel AV, Turner RD, Rifflet A, Acosta-Martin AE, Nichols A, Awad MM, Lyras D, Gomperts Boneca I, Bern M, Collins MO, Mesnage S. PGFinder, a novel analysis pipeline for the consistent, reproducible, and high-resolution structural analysis of bacterial peptidoglycans. eLife 2021; 10:70597. [PMID: 34579805 PMCID: PMC8478412 DOI: 10.7554/elife.70597] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/08/2021] [Indexed: 12/12/2022] Open
Abstract
Many software solutions are available for proteomics and glycomics studies, but none are ideal for the structural analysis of peptidoglycan (PG), the essential and major component of bacterial cell envelopes. It icomprises glycan chains and peptide stems, both containing unusual amino acids and sugars. This has forced the field to rely on manual analysis approaches, which are time-consuming, labour-intensive, and prone to error. The lack of automated tools has hampered the ability to perform high-throughput analyses and prevented the adoption of a standard methodology. Here, we describe a novel tool called PGFinder for the analysis of PG structure and demonstrate that it represents a powerful tool to quantify PG fragments and discover novel structural features. Our analysis workflow, which relies on open-access tools, is a breakthrough towards a consistent and reproducible analysis of bacterial PGs. It represents a significant advance towards peptidoglycomics as a full-fledged discipline.
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Affiliation(s)
- Ankur V Patel
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Robert D Turner
- Department of Computer Science, University of Sheffield, Sheffield, United Kingdom
| | - Aline Rifflet
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France.,INSERM, Équipe Avenir, Paris, France.,CNRS, UMR 2001 "Microbiologie intégrative et moléculaire", Paris, France
| | - Adelina E Acosta-Martin
- biOMICS Facility, Faculty of Science Mass Spectrometry Centre, University of Sheffield, Sheffield, United Kingdom
| | | | - Milena M Awad
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia.,Department of Microbiology, Monash University, Clayton, Australia
| | - Ivo Gomperts Boneca
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France.,INSERM, Équipe Avenir, Paris, France.,CNRS, UMR 2001 "Microbiologie intégrative et moléculaire", Paris, France
| | | | - Mark O Collins
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom.,biOMICS Facility, Faculty of Science Mass Spectrometry Centre, University of Sheffield, Sheffield, United Kingdom
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
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15
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Comparative Biofilm Assays Using Enterococcus faecalis OG1RF Identify New Determinants of Biofilm Formation. mBio 2021; 12:e0101121. [PMID: 34126766 PMCID: PMC8262879 DOI: 10.1128/mbio.01011-21] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecalis is a common commensal organism and a prolific nosocomial pathogen that causes biofilm-associated infections. Numerous E. faecalis OG1RF genes required for biofilm formation have been identified, but few studies have compared genetic determinants of biofilm formation and biofilm morphology across multiple conditions. Here, we cultured transposon (Tn) libraries in CDC biofilm reactors in two different media and used Tn sequencing (TnSeq) to identify core and accessory biofilm determinants, including many genes that are poorly characterized or annotated as hypothetical. Multiple secondary assays (96-well plates, submerged Aclar discs, and MultiRep biofilm reactors) were used to validate phenotypes of new biofilm determinants. We quantified biofilm cells and used fluorescence microscopy to visualize biofilms formed by six Tn mutants identified using TnSeq and found that disrupting these genes (OG1RF_10350, prsA, tig, OG1RF_10576, OG1RF_11288, and OG1RF_11456) leads to significant time- and medium-dependent changes in biofilm architecture. Structural predictions revealed potential roles in cell wall homeostasis for OG1RF_10350 and OG1RF_11288 and signaling for OG1RF_11456. Additionally, we identified growth medium-specific hallmarks of OG1RF biofilm morphology. This study demonstrates how E. faecalis biofilm architecture is modulated by growth medium and experimental conditions and identifies multiple new genetic determinants of biofilm formation.
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16
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Oechslin F, Menzi C, Moreillon P, Resch G. The multidomain architecture of a bacteriophage endolysin enables intramolecular synergism and regulation of bacterial lysis. J Biol Chem 2021; 296:100639. [PMID: 33838182 PMCID: PMC8144678 DOI: 10.1016/j.jbc.2021.100639] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/29/2021] [Accepted: 04/05/2021] [Indexed: 01/07/2023] Open
Abstract
Endolysins are peptidoglycan hydrolases produced at the end of the bacteriophage (phage) replication cycle to lyse the host cell. Endolysins in Gram-positive phages come in a variety of multimodular forms that combine different catalytic and cell wall binding domains. However, the reason why phages adopt endolysins with such complex multidomain architecture is not well understood. In this study, we used the Streptococcus dysgalactiae phage endolysin PlySK1249 as a model to investigate the role of multidomain architecture in phage-induced bacterial lysis and lysis regulation. PlySK1249 consists of an amidase (Ami) domain that lyses bacterial cells, a nonbacteriolytic endopeptidase (CHAP) domain that acts as a dechaining enzyme, and a central LysM cell wall binding domain. We observed that the Ami and CHAP domains synergized for peptidoglycan digestion and bacteriolysis in the native enzyme or when expressed individually and reunified. The CHAP endopeptidase resolved complex polymers of stem-peptides to dimers and helped the Ami domain to digest peptidoglycan to completion. We also found that PlySK1249 was subject to proteolytic cleavage by host cell wall proteases both in vitro and after phage induction. Cleavage disconnected the different domains by hydrolyzing their linker regions, thus hindering their bacteriolytic cooperation and possibly modulating the lytic activity of the enzyme. PlySK1249 cleavage by cell-wall-associated proteases may represent another example of phage adaptation toward the use of existing bacterial regulation mechanism for their own advantage. In addition, understanding more thoroughly the multidomain interplay of PlySK1249 broadens our knowledge on the ideal architecture of therapeutic antibacterial endolysins.
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Affiliation(s)
- Frank Oechslin
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
| | - Carmen Menzi
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Philippe Moreillon
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Gregory Resch
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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17
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Sexton DL, Herlihey FA, Brott AS, Crisante DA, Shepherdson E, Clarke AJ, Elliot MA. Roles of LysM and LytM domains in resuscitation-promoting factor (Rpf) activity and Rpf-mediated peptidoglycan cleavage and dormant spore reactivation. J Biol Chem 2020; 295:9171-9182. [PMID: 32434927 PMCID: PMC7335776 DOI: 10.1074/jbc.ra120.013994] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/15/2020] [Indexed: 11/06/2022] Open
Abstract
Bacterial dormancy can take many forms, including formation of Bacillus endospores, Streptomyces exospores, and metabolically latent Mycobacterium cells. In the actinobacteria, including the streptomycetes and mycobacteria, the rapid resuscitation from a dormant state requires the activities of a family of cell-wall lytic enzymes called resuscitation-promoting factors (Rpfs). Whether Rpf activity promotes resuscitation by generating peptidoglycan fragments (muropeptides) that function as signaling molecules for spore germination or by simply remodeling the dormant cell wall has been the subject of much debate. Here, to address this question, we used mutagenesis and peptidoglycan binding and cleavage assays to first gain broader insight into the biochemical function of diverse Rpf enzymes. We show that their LysM and LytM domains enhance Rpf enzyme activity; their LytM domain and, in some cases their LysM domain, also promoted peptidoglycan binding. We further demonstrate that the Rpfs function as endo-acting lytic transglycosylases, cleaving within the peptidoglycan backbone. We also found that unlike in other systems, Rpf activity in the streptomycetes is not correlated with peptidoglycan-responsive Ser/Thr kinases for cell signaling, and the germination of rpf mutant strains could not be stimulated by the addition of known germinants. Collectively, these results suggest that in Streptomyces, Rpfs have a structural rather than signaling function during spore germination, and that in the actinobacteria, any signaling function associated with spore resuscitation requires the activity of additional yet to be identified enzymes.
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Affiliation(s)
- Danielle L Sexton
- Michael G. DeGroote Institute for Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Canada
| | - Francesca A Herlihey
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Ashley S Brott
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - David A Crisante
- Michael G. DeGroote Institute for Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Canada
| | - Evan Shepherdson
- Michael G. DeGroote Institute for Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Canada
| | - Anthony J Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Marie A Elliot
- Michael G. DeGroote Institute for Infectious Disease Research and Department of Biology, McMaster University, Hamilton, Canada.
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18
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Christley S, Shogan B, Levine Z, Koo H, Guyton K, Owens S, Gilbert J, Zaborina O, Alverdy JC. Comparative genetics of Enterococcus faecalis intestinal tissue isolates before and after surgery in a rat model of colon anastomosis. PLoS One 2020; 15:e0232165. [PMID: 32343730 PMCID: PMC7188289 DOI: 10.1371/journal.pone.0232165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/08/2020] [Indexed: 12/17/2022] Open
Abstract
We have recently demonstrated that collagenolytic Enterococcus faecalis plays a key and causative role in the pathogenesis of anastomotic leak, an uncommon but potentially lethal complication characterized by disruption of the intestinal wound following segmental removal of the colon (resection) and its reconnection (anastomosis). Here we hypothesized that comparative genetic analysis of E. faecalis isolates present at the anastomotic wound site before and after surgery would shed insight into the mechanisms by which collagenolytic strains are selected for and predominate at sites of anastomotic disruption. Whole genome optical mapping of four pairs of isolates from rat colonic tissue obtained following surgical resection (herein named “pre-op” isolates) and then 6 days later from the anastomotic site (herein named “post-op” isolates) demonstrated that the isolates with higher collagenolytic activity formed a distinct cluster. In order to perform analysis at a deeper level, a single pair of E. faecalis isolates (16A pre-op and 16A post-op) was selected for whole genome sequencing and assembled using a hybrid assembly algorithm. Comparative genomics demonstrated absence of multiple gene clusters, notably a pathogenicity island in the post-op isolate. No differences were found in the fsr-gelE-sprE genes (EF1817-1822) responsible for regulation and production of collagenolytic activity. Analysis of unique genes among the 16A pre-op and post-op isolates revealed the predominance of transporter systems-related genes in the pre-op isolate and phage-related and hydrolytic enzyme-encoding genes in the post-op isolate. Despite genetic differences observed between pre-op and post-op isolates, the precise genetic determinants responsible for their differential expression of collagenolytic activity remains unknown.
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Affiliation(s)
- Scott Christley
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - Benjamin Shogan
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - Zoe Levine
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - Hyun Koo
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - Kristina Guyton
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - Sarah Owens
- Argonne National Laboratory, Argonne, IL, United States of America
| | - Jack Gilbert
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
- Argonne National Laboratory, Argonne, IL, United States of America
| | - Olga Zaborina
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
| | - John C. Alverdy
- Department of Surgery, University of Chicago, Chicago, IL, United States of America
- * E-mail:
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19
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Kim MH, Kim SY, Son JH, Kim SI, Lee H, Kim S, Shin M, Lee JC. Production of Membrane Vesicles by Enterococcus faecium Cultured With or Without Subinhibitory Concentrations of Antibiotics and Their Pathological Effects on Epithelial Cells. Front Cell Infect Microbiol 2019; 9:295. [PMID: 31475120 PMCID: PMC6702262 DOI: 10.3389/fcimb.2019.00295] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/30/2019] [Indexed: 12/25/2022] Open
Abstract
Enterococcus faecium is a clinically important pathogen associated with opportunistic infection and multi-drug resistance. E. faecium has been shown to produce membrane vesicles (MVs), but MV production by E. faecium under antibiotic stress conditions and the pathogenic traits thereof have yet to be determined. This study investigated the production of MVs in E. faecium ATCC 700221 cultured with sub-minimum inhibitory concentrations (MICs) of vancomycin or linezolid and determined their pathologic effects on colon epithelial Caco-2 cells. E. faecium ATCC 700221 cultured with 1/2 MIC of vancomycin or linezolid produced 3.0 and 1.5 times more MV proteins than bacteria cultured without antibiotics, respectively. Totals of 438, 461, and 513 proteins were identified in MVs from E. faecium cultured in brain heart infusion broth (MVs/BHI), BHI broth with 1/2 MIC of vancomycin (MVs/VAN), or BHI broth with 1/2 MIC of linezolid (MVs/LIN), respectively. Intact MVs/BHI induced cytotoxicity and the expression of pro-inflammatory cytokine and chemokine genes in Caco-2 cells in a dose-dependent manner, but proteinase K-treated MVs significantly suppressed these pro-inflammatory responses. MVs/LIN were more cytotoxic toward Caco-2 cells than MVs/BHI and MVs/VAN, whereas MVs/VAN stimulated more pro-inflammatory cytokine gene expression in Caco-2 cells than MVs/BHI and MVs/LIN. Overall results indicated that antibiotics modulate the biogenesis and proteomes of MVs in E. faecium at subinhibitory concentrations. MVs produced by E. faecium cultured under antibiotic stress conditions induce strong host cell responses that may contribute to the pathogenesis E. faecium.
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Affiliation(s)
- Mi Hyun Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Se Yeon Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Joo Hee Son
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Seung Il Kim
- Drug and Disease Target Team, Korea Basic Science Institute, Ochang, South Korea.,Department of Bio-Analytical Science, University of Science and Technology (UST), Daejeon, South Korea
| | - Hayoung Lee
- Drug and Disease Target Team, Korea Basic Science Institute, Ochang, South Korea.,Department of Bio-Analytical Science, University of Science and Technology (UST), Daejeon, South Korea
| | - Shukho Kim
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Minsang Shin
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Je Chul Lee
- Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, South Korea
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20
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Smith RE, Salamaga B, Szkuta P, Hajdamowicz N, Prajsnar TK, Bulmer GS, Fontaine T, Kołodziejczyk J, Herry JM, Hounslow AM, Williamson MP, Serror P, Mesnage S. Decoration of the enterococcal polysaccharide antigen EPA is essential for virulence, cell surface charge and interaction with effectors of the innate immune system. PLoS Pathog 2019; 15:e1007730. [PMID: 31048927 PMCID: PMC6497286 DOI: 10.1371/journal.ppat.1007730] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/26/2019] [Indexed: 12/13/2022] Open
Abstract
Enterococcus faecalis is an opportunistic pathogen with an intrinsically high resistance to lysozyme, a key effector of the innate immune system. This high level of resistance requires a complex network of transcriptional regulators and several genes (oatA, pgdA, dltA and sigV) acting synergistically to inhibit both the enzymatic and cationic antimicrobial peptide activities of lysozyme. We sought to identify novel genes modulating E. faecalis resistance to lysozyme. Random transposon mutagenesis carried out in the quadruple oatA/pgdA/dltA/sigV mutant led to the identification of several independent insertions clustered on the chromosome. These mutations were located in a locus referred to as the enterococcal polysaccharide antigen (EPA) variable region located downstream of the highly conserved epaA-epaR genes proposed to encode a core synthetic machinery. The epa variable region was previously proposed to be responsible for EPA decorations, but the role of this locus remains largely unknown. Here, we show that EPA decoration contributes to resistance towards charged antimicrobials and underpins virulence in the zebrafish model of infection by conferring resistance to phagocytosis. Collectively, our results indicate that the production of the EPA rhamnopolysaccharide backbone is not sufficient to promote E. faecalis infections and reveal an essential role of the modification of this surface polymer for enterococcal pathogenesis. Enterococcus faecalis is a commensal bacterium colonizing the gastro-intestinal tract of humans. This organism can cause life-threatening opportunistic infections and represents a reservoir for the transmission of antibiotic resistance genes such as resistance to vancomycin. E. faecalis strains responsible for nosocomial infections are also found in healthy individuals and the virulence factors identified so far are not strictly associated with clinical isolates. The molecular basis underpinning E. faecalis infections therefore remains unclear. In this work, we identify several mutations clustered on the chromosome, which play a role in the resistance of E. faecalis to effectors of the innate immune system such as lysozyme and bile salts. We show that the corresponding genes contribute to the decoration of a conserved polysaccharide called the enterococcal polysaccharide antigen and that this decoration is essential for E. faecalis virulence. This mechanism critical for pathogenesis represents an attractive therapeutic target to control enterococcal infections.
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Affiliation(s)
- Robert E. Smith
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Bartłomiej Salamaga
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Piotr Szkuta
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Natalia Hajdamowicz
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Tomasz K. Prajsnar
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Gregory S. Bulmer
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | | | - Justyna Kołodziejczyk
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Jean-Marie Herry
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Andrea M. Hounslow
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Mike P. Williamson
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Pascale Serror
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
- * E-mail: (PS); (SM)
| | - Stéphane Mesnage
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
- * E-mail: (PS); (SM)
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21
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Kitaoku Y, Nishimura S, Hirono T, Suginta W, Ohnuma T, Fukamizo T. Structures and chitin-binding properties of two N-terminal lysin motifs (LysMs) found in a chitinase from Volvox carteri. Glycobiology 2019; 29:565-575. [DOI: 10.1093/glycob/cwz024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 03/18/2019] [Accepted: 04/03/2019] [Indexed: 02/01/2023] Open
Affiliation(s)
- Yoshihito Kitaoku
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara Japan
| | - Shigenori Nishimura
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan
| | - Takeru Hirono
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara Japan
| | - Wipa Suginta
- School of Biomolecular Science and Engineering, VISTEC (Vidyasirimedhi Institute of Science and Technology), Tumbol Payupnai, Wangchan Valley, Rayong, Thailand
| | - Takayuki Ohnuma
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara Japan
| | - Tamo Fukamizo
- Department of Advanced Bioscience, Kindai University, 3327-204 Nakamachi, Nara Japan
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22
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Duchêne MC, Rolain T, Knoops A, Courtin P, Chapot-Chartier MP, Dufrêne YF, Hallet BF, Hols P. Distinct and Specific Role of NlpC/P60 Endopeptidases LytA and LytB in Cell Elongation and Division of Lactobacillus plantarum. Front Microbiol 2019; 10:713. [PMID: 31031721 PMCID: PMC6473061 DOI: 10.3389/fmicb.2019.00713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/21/2019] [Indexed: 11/22/2022] Open
Abstract
Peptidoglycan (PG) is an essential lattice of the bacterial cell wall that needs to be continuously remodeled to allow growth. This task is ensured by the concerted action of PG synthases that insert new material in the pre-existing structure and PG hydrolases (PGHs) that cleave the PG meshwork at critical sites for its processing. Contrasting with Bacillus subtilis that contains more than 35 PGHs, Lactobacillus plantarum is a non-sporulating rod-shaped bacterium that is predicted to possess a minimal set of 12 PGHs. Their role in morphogenesis and cell cycle remains mostly unexplored, except for the involvement of the glucosaminidase Acm2 in cell separation and the NlpC/P60 D, L-endopeptidase LytA in cell shape maintenance. Besides LytA, L. plantarum encodes three additional NlpC/P60 endopeptidases (i.e., LytB, LytC and LytD). The in silico analysis of these four endopeptidases suggests that they could have redundant functions based on their modular organization, forming two pairs of paralogous enzymes. In this work, we investigate the role of each Lyt endopeptidase in cell morphogenesis in order to evaluate their distinct or redundant functions, and eventually their synthetic lethality. We show that the paralogous LytC and LytD enzymes are not required for cell shape maintenance, which may indicate an accessory role such as in PG recycling. In contrast, LytA and LytB appear to be key players of the cell cycle. We show here that LytA is required for cell elongation while LytB is involved in the spatio-temporal regulation of cell division. In addition, both PGHs are involved in the proper positioning of the division site. The absence of LytA activity is responsible for the asymmetrical positioning of septa in round cells while the lack of LytB results in a lateral misplacement of division planes in rod-shaped cells. Finally, we show that the co-inactivation of LytA and LytB is synthetically affecting cell growth, which confirms the key roles played by both enzymes in PG remodeling during the cell cycle of L. plantarum. Based on the large distribution of NlpC/P60 endopeptidases in low-GC Gram-positive bacteria, these enzymes are attractive targets for the discovery of novel antimicrobial compounds.
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Affiliation(s)
- Marie-Clémence Duchêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Thomas Rolain
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Adrien Knoops
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Courtin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | | | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Bernard F Hallet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Hols
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
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23
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Yokoyama CC, Baldridge MT, Leung DW, Zhao G, Desai C, Liu TC, Diaz-Ochoa VE, Huynh JP, Kimmey JM, Sennott EL, Hole CR, Idol RA, Park S, Storek KM, Wang C, Hwang S, Viehmann Milam A, Chen E, Kerrinnes T, Starnbach MN, Handley SA, Mysorekar IU, Allen PM, Monack DM, Dinauer MC, Doering TL, Tsolis RM, Dworkin JE, Stallings CL, Amarasinghe GK, Micchelli CA, Virgin HW. LysMD3 is a type II membrane protein without an in vivo role in the response to a range of pathogens. J Biol Chem 2018; 293:6022-6038. [PMID: 29496999 PMCID: PMC5912457 DOI: 10.1074/jbc.ra117.001246] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/31/2018] [Indexed: 12/22/2022] Open
Abstract
Germline-encoded receptors recognizing common pathogen-associated molecular patterns are a central element of the innate immune system and play an important role in shaping the host response to infection. Many of the innate immune molecules central to these signaling pathways are evolutionarily conserved. LysMD3 is a novel molecule containing a putative peptidoglycan-binding domain that has orthologs in humans, mice, zebrafish, flies, and worms. We found that the lysin motif (LysM) of LysMD3 is likely related to a previously described peptidoglycan-binding LysM found in bacteria. Mouse LysMD3 is a type II integral membrane protein that co-localizes with GM130+ structures, consistent with localization to the Golgi apparatus. We describe here two lines of mLysMD3-deficient mice for in vivo characterization of mLysMD3 function. We found that mLysMD3-deficient mice were born at Mendelian ratios and had no obvious pathological abnormalities. They also exhibited no obvious immune response deficiencies in a number of models of infection and inflammation. mLysMD3-deficient mice exhibited no signs of intestinal dysbiosis by 16S analysis or alterations in intestinal gene expression by RNA sequencing. We conclude that mLysMD3 contains a LysM with cytoplasmic orientation, but we were unable to define a physiological role for the molecule in vivo.
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Affiliation(s)
| | | | - Daisy W Leung
- From the Departments of Pathology and Immunology and
| | - Guoyan Zhao
- From the Departments of Pathology and Immunology and
| | - Chandni Desai
- From the Departments of Pathology and Immunology and
| | - Ta-Chiang Liu
- From the Departments of Pathology and Immunology and
| | - Vladimir E Diaz-Ochoa
- the Department of Medical Microbiology and Immunology, University of California, Davis, California 95161
| | | | | | - Erica L Sennott
- the Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | | | | | - Sunmin Park
- From the Departments of Pathology and Immunology and
| | | | | | - Seungmin Hwang
- the Department of Pathology, University of Chicago, Chicago, Illinois 60637
| | | | - Eric Chen
- the Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720
| | - Tobias Kerrinnes
- the Department of Medical Microbiology and Immunology, University of California, Davis, California 95161
| | - Michael N Starnbach
- the Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | | | - Indira U Mysorekar
- From the Departments of Pathology and Immunology and
- Obstetrics and Gynecology, and
| | - Paul M Allen
- From the Departments of Pathology and Immunology and
| | - Denise M Monack
- the Department of Microbiology and Immunology, Stanford University, Stanford, California 94305
| | | | | | - Renee M Tsolis
- the Department of Medical Microbiology and Immunology, University of California, Davis, California 95161
| | - Jonathan E Dworkin
- the Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, and
| | | | | | - Craig A Micchelli
- Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri 63110
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24
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Serrano-Maldonado CE, García-Cano I, González-Canto A, Ruiz-May E, Elizalde-Contreras JM, Quirasco M. Cloning and Characterization of a Novel N-acetylglucosaminidase (AtlD) from Enterococcus faecalis. J Mol Microbiol Biotechnol 2018; 28:14-27. [PMID: 29510391 DOI: 10.1159/000486757] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 01/10/2018] [Indexed: 12/28/2022] Open
Abstract
The atlD gene from an Enterococcus faecalis strain isolated from a Mexican artisanal cheese was cloned, sequenced and expressed in Escherichia coli in order to perform a biochemical characterization. A partial amino acid sequence of the heterologous protein was obtained by LC-MS/MS, and it corresponded to a novel peptidoglycan hydrolase designated AtlD. Its molecular mass was 62-75 kDa, as determined by SDS-PAGE, zymography, Western blot, and exclusion chromatography. Electrofocusing rendered an isoelectric point (pI) of 4.8. It exhibited N-acetylglucosaminidase activity, with an optimal pH and temperature between 6-7 and 50°C, respectively. It retained 85% activity with NaCl at 1,000 mM, but it was susceptible to divalent ions, particularly Zn2+. It showed antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and enterococcal strains of clinical origin. Due to the fact that it showed activity versus pathogenic bacteria, and because of its capabilities under ionic strength, temperature, and pH values present in food matrices, it could be applied as an additive in the food industry. This study will aid in the design of new antibacterial agents of natural origin to combat food-borne diseases, and it could be used as an industrial or hospital hygiene agent as well.
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Affiliation(s)
- Carlos Eduardo Serrano-Maldonado
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Israel García-Cano
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Augusto González-Canto
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México y Hospital General de México, Mexico City, Mexico
| | - Eliel Ruiz-May
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C., Cluster Científico y Tecnológico BioMimic®, Xalapa, Mexico
| | - Jose Miguel Elizalde-Contreras
- Red de Estudios Moleculares Avanzados, Instituto de Ecología A.C., Cluster Científico y Tecnológico BioMimic®, Xalapa, Mexico
| | - Maricarmen Quirasco
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
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25
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Goh HMS, Yong MHA, Chong KKL, Kline KA. Model systems for the study of Enterococcal colonization and infection. Virulence 2017; 8:1525-1562. [PMID: 28102784 PMCID: PMC5810481 DOI: 10.1080/21505594.2017.1279766] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 12/30/2016] [Accepted: 01/04/2017] [Indexed: 02/07/2023] Open
Abstract
Enterococcus faecalis and Enterococcus faecium are common inhabitants of the human gastrointestinal tract, as well as frequent opportunistic pathogens. Enterococci cause a range of infections including, most frequently, infections of the urinary tract, catheterized urinary tract, bloodstream, wounds and surgical sites, and heart valves in endocarditis. Enterococcal infections are often biofilm-associated, polymicrobial in nature, and resistant to antibiotics of last resort. Understanding Enterococcal mechanisms of colonization and pathogenesis are important for identifying new ways to manage and intervene with these infections. We review vertebrate and invertebrate model systems applied to study the most common E. faecalis and E. faecium infections, with emphasis on recent findings examining Enterococcal-host interactions using these models. We discuss strengths and shortcomings of each model, propose future animal models not yet applied to study mono- and polymicrobial infections involving E. faecalis and E. faecium, and comment on the significance of anti-virulence strategies derived from a fundamental understanding of host-pathogen interactions in model systems.
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Affiliation(s)
- H. M. Sharon Goh
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - M. H. Adeline Yong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kelvin Kian Long Chong
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate School, Nanyang Technological University, Singapore
| | - Kimberly A. Kline
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
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26
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Bacterial size matters: Multiple mechanisms controlling septum cleavage and diplococcus formation are critical for the virulence of the opportunistic pathogen Enterococcus faecalis. PLoS Pathog 2017; 13:e1006526. [PMID: 28742152 PMCID: PMC5542707 DOI: 10.1371/journal.ppat.1006526] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 08/03/2017] [Accepted: 07/12/2017] [Indexed: 12/02/2022] Open
Abstract
Enterococcus faecalis is an opportunistic pathogen frequently isolated in clinical settings. This organism is intrinsically resistant to several clinically relevant antibiotics and can transfer resistance to other pathogens. Although E. faecalis has emerged as a major nosocomial pathogen, the mechanisms underlying the virulence of this organism remain elusive. We studied the regulation of daughter cell separation during growth and explored the impact of this process on pathogenesis. We demonstrate that the activity of the AtlA peptidoglycan hydrolase, an enzyme dedicated to septum cleavage, is controlled by several mechanisms, including glycosylation and recognition of the peptidoglycan substrate. We show that the long cell chains of E. faecalis mutants are more susceptible to phagocytosis and are no longer able to cause lethality in the zebrafish model of infection. Altogether, this work indicates that control of cell separation during division underpins the pathogenesis of E. faecalis infections and represents a novel enterococcal virulence factor. We propose that inhibition of septum cleavage during division represents an attractive therapeutic strategy to control infections. Enterococcus faecalis is a commensal bacterium that colonizes the gastrointestinal tract of humans. This organism is an opportunistic pathogen that can cause a wide range of life-threatening infections in hospital settings. Despite the identification of several virulence factors, the mechanisms by which E. faecalis evades host immunity and causes infections remains poorly understood. Here, we explore how the formation of diplococci and short cell chains, a distinctive property of E. faecalis, contributes to pathogenesis. We describe several mechanisms that control the activity of AtlA, the enzyme dedicated to septum cleavage during division. Using a combination of in vitro assays and flow cytometry analyses of E. faecalis mutants, we show that AtlA activity is regulated by several mechanisms. We reveal that during pathogenesis, AtlA activity is critical for overcoming the host immune response. In the absence of AtlA, the long cell chains of E. faecalis mutants are more susceptible to phagocytosis and can no longer cause lethality in the zebrafish model of infection, thus indicating that control of cell chain length is a novel virulence factor in E. faecalis. This work highlights a link between cell division and pathogenesis and suggests that cell separation represents a step that can be targeted to control bacterial infections.
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27
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Conjugative type IV secretion in Gram-positive pathogens: TraG, a lytic transglycosylase and endopeptidase, interacts with translocation channel protein TraM. Plasmid 2017; 91:9-18. [PMID: 28219792 DOI: 10.1016/j.plasmid.2017.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/30/2017] [Accepted: 02/02/2017] [Indexed: 11/24/2022]
Abstract
Conjugative transfer plays a major role in the transmission of antibiotic resistance in bacteria. pIP501 is a Gram-positive conjugative model plasmid with the broadest transfer host-range known so far and is frequently found in Enterococcus faecalis and Enterococcus faecium clinical isolates. The pIP501 type IV secretion system is encoded by 15 transfer genes. In this work, we focus on the VirB1-like protein TraG, a modular peptidoglycan metabolizing enzyme, and the VirB8-homolog TraM, a potential member of the translocation channel. By providing full-length traG in trans, but not with a truncated variant, we achieved full recovery of wild type transfer efficiency in the traG-knockout mutant E. faecalis pIP501ΔtraG. With peptidoglycan digestion experiments and tandem mass spectrometry we could assign lytic transglycosylase and endopeptidase activity to TraG, with the CHAP domain alone displaying endopeptidase activity. We identified a novel interaction between TraG and TraM in a bacterial-2-hybrid assay. In addition we found that both proteins localize in focal spots at the E. faecalis cell membrane using immunostaining and fluorescence microscopy. Extracellular protease digestion to evaluate protein cell surface exposure revealed that correct membrane localization of TraM requires the transmembrane helix of TraG. Thus, we suggest an essential role for TraG in the assembly of the pIP501 type IV secretion system.
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28
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Wang N, Hasegawa H, Huang CY, Fukase K, Fujimoto Y. Synthesis of Peptidoglycan Fragments from Enterococcus faecalis with Fmoc-Strategy for Glycan Elongation. Chem Asian J 2016; 12:27-30. [PMID: 27868361 DOI: 10.1002/asia.201601357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 11/03/2016] [Indexed: 12/21/2022]
Abstract
Peptidoglycan (PGN) is an essential structural component of the bacterial cell wall conferring cell shape, which can be recognized by host-recognition proteins and receptors as well as bacterial surface proteins. In this work, the PGN partial structures from Enterococcus faecalis that contain a tetrasaccharide and an octasaccharide with a unique heptapeptide were synthesized via an Fmoc-strategy for elongation of the glycan chains. Namely, a 4'-O-Fmoc-protected disaccharide was utilized as the key intermediate in this efficient synthetic pathway for preparing various PGN fragments. Both the tetrasaccharide and octasaccharide with the unique heptapeptide were successfully synthesized for the first time.
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Affiliation(s)
- Ning Wang
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Hiroki Hasegawa
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Cheng-Yuan Huang
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Koichi Fukase
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan
| | - Yukari Fujimoto
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043, Japan.,Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
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29
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DUF3380 Domain from a Salmonella Phage Endolysin Shows Potent N-Acetylmuramidase Activity. Appl Environ Microbiol 2016; 82:4975-81. [PMID: 27287318 DOI: 10.1128/aem.00446-16] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 06/02/2016] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Bacteriophage-encoded endolysins are highly diverse enzymes that cleave the bacterial peptidoglycan layer. Current research focuses on their potential applications in medicine, in food conservation, and as biotechnological tools. Despite the wealth of applications relying on the use of endolysin, little is known about the enzymatic properties of these enzymes, especially in the case of endolysins of bacteriophages infecting Gram-negative species. Automated genome annotations therefore remain to be confirmed. Here, we report the biochemical analysis and cleavage site determination of a novel Salmonella bacteriophage endolysin, Gp110, which comprises an uncharacterized domain of unknown function (DUF3380; pfam11860) in its C terminus and shows a higher specific activity (34,240 U/μM) than that of 14 previously characterized endolysins active against peptidoglycan from Gram-negative bacteria (corresponding to 1.7- to 364-fold higher activity). Gp110 is a modular endolysin with an optimal pH of enzymatic activity of pH 8 and elevated thermal resistance. Reverse-phase high-performance liquid chromatography (RP-HPLC) analysis coupled to mass spectrometry showed that DUF3380 has N-acetylmuramidase (lysozyme) activity cleaving the β-(1,4) glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine residues. Gp110 is active against directly cross-linked peptidoglycans with various peptide stem compositions, making it an attractive enzyme for developing novel antimicrobial agents. IMPORTANCE We report the functional and biochemical characterization of the Salmonella phage endolysin Gp110. This endolysin has a modular structure with an enzymatically active domain and a cell wall binding domain. The enzymatic activity of this endolysin exceeds that of all other endolysins previously characterized using the same methods. A domain of unknown function (DUF3380) is responsible for this high enzymatic activity. We report that DUF3380 has N-acetylmuramidase activity against directly cross-linked peptidoglycans with various peptide stem compositions. This experimentally verified activity allows better classification and understanding of the enzymatic activities of endolysins, which mostly are inferred by sequence similarities. Three-dimensional structure predictions for Gp110 suggest a fold that is completely different from that of known structures of enzymes with the same peptidoglycan cleavage specificity, making this endolysin quite unique. All of these features, combined with increased thermal resistance, make Gp110 an attractive candidate for engineering novel endolysin-based antibacterials.
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30
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Wang N, Hirata A, Nokihara K, Fukase K, Fujimoto Y. Peptidoglycan microarray as a novel tool to explore protein-ligand recognition. Biopolymers 2016; 106:422-9. [DOI: 10.1002/bip.22807] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 12/15/2015] [Accepted: 12/18/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Ning Wang
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Akiyoshi Hirata
- HiPep Laboratories; 486-46 Nakatsukasa-Cho Kamigyo-Ku, Kyoto 602-8158 Japan
| | - Kiyoshi Nokihara
- HiPep Laboratories; 486-46 Nakatsukasa-Cho Kamigyo-Ku, Kyoto 602-8158 Japan
| | - Koichi Fukase
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
| | - Yukari Fujimoto
- Department of Chemistry, Graduate School of Science; Osaka University; 1-1 Machikaneyama Toyonaka Osaka 560-0043 Japan
- Department of Chemistry, Faculty of Science and Technology; Keio University; 3-14-1 Hiyoshi Kohoku-Ku, Yokohama Kanagawa 223-8522 Japan
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31
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Wu Z, Shao J, Ren H, Tang H, Zhou M, Dai J, Lai L, Yao H, Fan H, Chen D, Zong J, Lu C. A Streptococcus suis LysM domain surface protein contributes to bacterial virulence. Vet Microbiol 2016; 187:64-69. [PMID: 27066710 DOI: 10.1016/j.vetmic.2016.03.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/16/2016] [Accepted: 03/25/2016] [Indexed: 01/20/2023]
Abstract
Streptococcus suis (SS) is a major swine pathogen, as well as a zoonotic agent for humans. Numerous factors contribute to SS virulence, but the pathogenesis of SS infection is poorly understood. Here, we show that a novel SS surface protein containing a LysM at the N-terminus (SS9-LysM) contributes to SS virulence. Homology analysis revealed that the amino acid sequence of SS9-LysM from the SS strain GZ0565 shares 99.8-68.7% identity with homologous proteins from other SS strains and 41.2% identity with Group B Streptococcal protective antigen Sip. Immunization experiments showed that 7 out of 30 mice immunized with recombinant SS9-LysM were protected against challenge with the virulent GZ0565 strain, while all of the control mice died within 48h following bacterial challenge. In mouse infection model, the virulence of the SS9-LysM deletion mutant (ΔSS9-LysM) was reduced compared with the wild-type (WT) strain GZ0565 and SS9-LysM complemented strain. In addition, ΔSS9-LysM was significantly more sensitive to killing by pig blood ex vivo and mouse blood in vivo compared with the WT strain and SS9-LysM complemented strain. In vivo transcriptome analysis in mouse blood showed that the WT strain reduced the expression of host genes related to iron-binding by SS9-LysM. Moreover, the total free iron concentration in blood from infected mice was significantly lower for the ΔSS9-LysM strain compared with the WT strain. Together, our data reveal that SS9-LysM facilitates SS survival within blood by releasing more free iron from the host. This represents a new mechanism of SS pathogenesis.
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Affiliation(s)
- Zongfu Wu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China.
| | - Jing Shao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Haiyan Ren
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Huanyu Tang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Mingyao Zhou
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Jiao Dai
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Liying Lai
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Huochun Yao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Dai Chen
- Novel Bioinformatics Co., Ltd., Shanghai, China
| | - Jie Zong
- Novel Bioinformatics Co., Ltd., Shanghai, China
| | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210095, China; OIE Reference Lab for Swine Streptococcosis, Nanjing 210095, China.
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32
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Oliveira H, Vilas Boas D, Mesnage S, Kluskens LD, Lavigne R, Sillankorva S, Secundo F, Azeredo J. Structural and Enzymatic Characterization of ABgp46, a Novel Phage Endolysin with Broad Anti-Gram-Negative Bacterial Activity. Front Microbiol 2016; 7:208. [PMID: 26955368 PMCID: PMC4768612 DOI: 10.3389/fmicb.2016.00208] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 02/08/2016] [Indexed: 12/12/2022] Open
Abstract
The present study demonstrates the antibacterial potential of a phage endolysin against Gram-negative pathogens, particularly against multidrug resistant strains of Acinetobacter baumannii. We have cloned, heterologously expressed and characterized a novel endolysin (ABgp46) from Acinetobacter phage vb_AbaP_CEB1 and tested its antibacterial activity against several multidrug-resistant A. baumannii strains. LC-MS revealed that ABgp46 is an N-acetylmuramidase, that is also active over a broad pH range (4.0-10.0) and temperatures up to 50°C. Interestingly, ABgp46 has intrinsic and specific anti-A. baumannii activity, reducing multidrug resistant strains by up to 2 logs within 2 h. By combining ABgp46 with several organic acids that act as outer membrane permeabilizing agents, it is possible to increase and broaden antibacterial activity to include other Gram-negative bacterial pathogens. In the presence of citric and malic acid, ABgp46 reduces A. baumannii below the detection limit (>5 log) and more than 4 logs Pseudomonas aeruginosa and Salmonella typhimurium strains. Overall, this globular endolysin exhibits a broad and high activity against Gram-negative pathogens, that can be enhanced in presence of citric and malic acid, and be used in human and veterinary medicine.
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Affiliation(s)
- Hugo Oliveira
- Centre of Biological Engineering, Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho Braga, Portugal
| | - Diana Vilas Boas
- Centre of Biological Engineering, Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho Braga, Portugal
| | - Stéphane Mesnage
- Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield Sheffield, UK
| | - Leon D Kluskens
- Centre of Biological Engineering, Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho Braga, Portugal
| | - Rob Lavigne
- Laboratory of Gene Technology, KU Leuven Leuven, Belgium
| | - Sanna Sillankorva
- Centre of Biological Engineering, Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho Braga, Portugal
| | - Francesco Secundo
- Istituto di Chimica del Riconoscimento Molecolare - Consiglio Nazionale delle Ricerche Milano, Italy
| | - Joana Azeredo
- Centre of Biological Engineering, Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho Braga, Portugal
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33
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Structural and Biochemical Insights into the Peptidoglycan Hydrolase Domain of FlgJ from Salmonella typhimurium. PLoS One 2016; 11:e0149204. [PMID: 26871950 PMCID: PMC4752226 DOI: 10.1371/journal.pone.0149204] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 01/28/2016] [Indexed: 11/19/2022] Open
Abstract
FlgJ is a glycoside hydrolase (GH) enzyme belonging to the Carbohydrate Active enZyme (CAZy) family GH73. It facilitates passage of the bacterial flagellum through the peptidoglycan (PG) layer by cleaving the β-1,4 glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid sugars that comprise the glycan strands of PG. Here we describe the crystal structure of the GH domain of FlgJ from bacterial pathogen Salmonella typhimurium (StFlgJ). Interestingly, the active site of StFlgJ was blocked by the C-terminal α-helix of a neighbouring symmetry mate and a β-hairpin containing the putative catalytic glutamic acid residue Glu223 was poorly resolved and could not be completely modeled into the electron density, suggesting it is flexible. Previous reports have shown that the GH73 enzyme Auto from Listeria monocytogenes is inhibited by an N-terminal α-helix that may occlude the active site in similar fashion. To investigate if the C-terminus of StFlgJ inhibits GH activity, the glycolytic activity of StFlgJ was assessed with and without the C-terminal α-helix. The GH activity of StFlgJ was unaffected by the presence or absence of the α-helix, suggesting it is not involved in regulating activity. Removal of the C-terminal α-helix did, however, allow a crystal structure of the domain to be obtained where the flexible β-hairpin containing residue Glu223 was entirely resolved. The β-hairpin was positioned such that the active site groove was fully solvent-exposed, placing Glu223 nearly 21.6 Å away from the putative general acid/base residue Glu184, which is too far apart for these two residues to coordinate glycosidic bond hydrolysis. The mobile nature of the StFlgJ β-hairpin is consistent with structural studies of related GH73 enzymes, suggesting that a dynamic active site may be common to many GH73 enzymes, in which the active site opens to capture substrate and then closes to correctly orient active site residues for catalysis.
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Najjari A, Amairi H, Chaillou S, Mora D, Boudabous A, Zagorec M, Ouzari H. Phenotypic and genotypic characterization of peptidoglycan hydrolases of Lactobacillus sakei. J Adv Res 2016; 7:155-63. [PMID: 26843981 PMCID: PMC4703478 DOI: 10.1016/j.jare.2015.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 11/26/2022] Open
Abstract
Lactobacillus sakei, a lactic acid bacterium naturally found in fresh meat and sea products, is considered to be one of the most important bacterial species involved in meat fermentation and bio-preservation. Several enzymes of Lb. sakei species contributing to microbial safeguarding and organoleptic properties of fermented-meat were studied. However, the specific autolytic mechanisms and associated enzymes involved in Lb. sakei are not well understood. The autolytic phenotype of 22 Lb. sakei strains isolated from Tunisian meat and seafood products was evaluated under starvation conditions, at pH 6.5 and 8.5, and in the presence of different carbon sources. A higher autolytic rate was observed when cells were grown in the presence of glucose and incubated at pH 6.5. Almost all strains showed high resistance to mutanolysin, indicating a minor role of muramidases in Lb. sakei cell lysis. Using Micrococcus lysodeikticus cells as a substrate in activity gels zymogram, peptidoglycan hydrolase (PGH) patterns for all strains was characterized by two lytic bands of ∼80 (B1) and ∼70 kDa (B2), except for strain BMG.167 which harbored two activity signals at a lower MW. Lytic activity was retained in high salt and in acid/basic conditions and was active toward cells of Lb. sakei, Listeria monocytogenes, Listeria ivanovii and Listeria innocua. Analysis of five putative PGH genes found in the Lb. sakei 23 K model strain genome, indicated that one gene, lsa1437, could encode a PGH (N-acetylmuramoyl-L-alanine amidase) containing B1 and B2 as isoforms. According to this hypothesis, strain BMG.167 showed an allelic version of lsa1437 gene deleted of one of the five LysM domains, leading to a reduction in the MW of lytic bands and the high autolytic rate of this strain. Characterization of autolytic phenotype of Lb. sakei should expand the knowledge of their role in fermentation processes where they represent the dominant species.
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Affiliation(s)
- Afef Najjari
- Université Tunis El Manar, Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Campus Universitaire, 2092 Tunis, Tunisia
| | - Houda Amairi
- Université Tunis El Manar, Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Campus Universitaire, 2092 Tunis, Tunisia
| | - Stéphane Chaillou
- Unité Flore Lactique et Environnement Carné, UR309, INRA, Domaine de Vilvert, F-78350 Jouy en Josas, France
| | - Diego Mora
- Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Università degli Studi di Milano, Milan, Italy
| | - Abdellatif Boudabous
- Université Tunis El Manar, Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Campus Universitaire, 2092 Tunis, Tunisia
| | - Monique Zagorec
- Unité Flore Lactique et Environnement Carné, UR309, INRA, Domaine de Vilvert, F-78350 Jouy en Josas, France
| | - Hadda Ouzari
- Université Tunis El Manar, Faculté des Sciences de Tunis, LR03ES03 Laboratoire de Microbiologie et Biomolécules Actives, Campus Universitaire, 2092 Tunis, Tunisia
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Akcapinar GB, Kappel L, Sezerman OU, Seidl-Seiboth V. Molecular diversity of LysM carbohydrate-binding motifs in fungi. Curr Genet 2015; 61:103-13. [PMID: 25589417 PMCID: PMC4392113 DOI: 10.1007/s00294-014-0471-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 11/27/2022]
Abstract
LysM motifs are carbohydrate-binding modules found in prokaryotes and eukaryotes. They bind to N-acetylglucosamine-containing carbohydrates, such as chitin, chitio-oligosaccharides and peptidoglycan. In this review, we summarize the features of the protein architecture of LysM-containing proteins in fungi and discuss their so far known biochemical properties, transcriptional profiles and biological functions. Further, based on data from evolutionary analyses and consensus pattern profiling of fungal LysM motifs, we show that they can be classified into a fungal-specific group and a fungal/bacterial group. This facilitates the classification and selection of further LysM proteins for detailed analyses and will contribute to widening our understanding of the functional spectrum of this protein family in fungi. Fungal LysM motifs are predominantly found in subgroup C chitinases and in LysM effector proteins, which are secreted proteins with LysM motifs but no catalytic domains. In enzymes, LysM motifs mediate the attachment to insoluble carbon sources. In plants, receptors containing LysM motifs are responsible for the perception of chitin-oligosaccharides and are involved in beneficial symbiotic interactions between plants and bacteria or fungi, as well as plant defence responses. In plant pathogenic fungi, LysM effector proteins have already been shown to have important functions in the dampening of host defence responses as well as protective functions of fungal hyphae against chitinases. However, the large number and diversity of proteins with LysM motifs that are being unravelled in fungal genome sequencing projects suggest that the functional repertoire of LysM effector proteins in fungi is only partially discovered so far.
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Affiliation(s)
- Gunseli Bayram Akcapinar
- Faculty of Natural Sciences and Engineering, Biological Sciences and Bioengineering, Sabanci University, Tuzla, 34956 Istanbul, Turkey
- Present Address: Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Lisa Kappel
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
| | - Osman Ugur Sezerman
- Faculty of Natural Sciences and Engineering, Biological Sciences and Bioengineering, Sabanci University, Tuzla, 34956 Istanbul, Turkey
| | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, Vienna University of Technology, Gumpendorfer Strasse 1a, 1060 Vienna, Austria
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Bacteriocin protein BacL1 of Enterococcus faecalis targets cell division loci and specifically recognizes L-Ala2-cross-bridged peptidoglycan. J Bacteriol 2014; 197:286-95. [PMID: 25368300 DOI: 10.1128/jb.02203-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Bacteriocin 41 (Bac41) is produced from clinical isolates of Enterococcus faecalis and consists of two extracellular proteins, BacL1 and BacA. We previously reported that BacL1 protein (595 amino acids, 64.5 kDa) is a bacteriolytic peptidoglycan D-isoglutamyl-L-lysine endopeptidase that induces cell lysis of E. faecalis when an accessory factor, BacA, is copresent. However, the target of BacL1 remains unknown. In this study, we investigated the targeting specificity of BacL1. Fluorescence microscopy analysis using fluorescent dye-conjugated recombinant protein demonstrated that BacL1 specifically localized at the cell division-associated site, including the equatorial ring, division septum, and nascent cell wall, on the cell surface of target E. faecalis cells. This specific targeting was dependent on the triple repeat of the SH3 domain located in the region from amino acid 329 to 590 of BacL1. Repression of cell growth due to the stationary state of the growth phase or to treatment with bacteriostatic antibiotics rescued bacteria from the bacteriolytic activity of BacL1 and BacA. The static growth state also abolished the binding and targeting of BacL1 to the cell division-associated site. Furthermore, the targeting of BacL1 was detectable among Gram-positive bacteria with an L-Ala-L-Ala-cross-bridging peptidoglycan, including E. faecalis, Streptococcus pyogenes, or Streptococcus pneumoniae, but not among bacteria with alternate peptidoglycan structures, such as Enterococcus faecium, Enterococcus hirae, Staphylococcus aureus, or Listeria monocytogenes. These data suggest that BacL1 specifically targets the L-Ala-L-Ala-cross-bridged peptidoglycan and potentially lyses the E. faecalis cells during cell division.
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García-Cano I, Serrano-Maldonado CE, Olvera-García M, Delgado-Arciniega E, Peña-Montes C, Mendoza-Hernández G, Quirasco M. Antibacterial activity produced by Enterococcus spp. isolated from an artisanal Mexican dairy product, Cotija cheese. Lebensm Wiss Technol 2014. [DOI: 10.1016/j.lwt.2014.04.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Lipski A, Hervé M, Lombard V, Nurizzo D, Mengin-Lecreulx D, Bourne Y, Vincent F. Structural and biochemical characterization of the β-N-acetylglucosaminidase from Thermotoga maritima: toward rationalization of mechanistic knowledge in the GH73 family. Glycobiology 2014; 25:319-30. [PMID: 25344445 DOI: 10.1093/glycob/cwu113] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Members of the GH73 glycosidase family cleave the β-1,4-glycosidic bond between the N-acetylglucosaminyl (GlcNAc) and N-acetylmuramyl (MurNAc) moieties in bacterial peptidoglycan. A catalytic mechanism has been proposed for members FlgJ, Auto, AcmA and Atl(WM) and the structural analysis of FlgJ and Auto revealed a conserved α/β fold reminiscent of the distantly related GH23 lysozyme. Comparison of the active site residues reveals variability in the nature of the catalytic general base suggesting two distinct catalytic mechanisms: an inverting mechanism involving two distant glutamate residues and a substrate-assisted mechanism involving anchimeric assistance by the C2-acetamido group of the GlcNAc moiety. Herein, we present the biochemical characterization and crystal structure of TM0633 from the hyperthermophilic bacterium Thermotoga maritima. TM0633 adopts the α/β fold of the family and displays β-N-acetylglucosaminidase activity on intact peptidoglycan sacculi. Site-directed mutagenesis identifies Glu34, Glu65 and Tyr118 as important residues for catalysis. A thorough bioinformatic analysis of the GH73 sequences identified five phylogenetic clusters. TM0633, FlgJ and Auto belong to a group of three clusters that conserve two carboxylate residues involved in a classical inverting acid-base mechanism. Members of the other two clusters lack a conserved catalytic general base supporting a substrate-assisted mechanism. Molecular modeling of representative members from each cluster suggests that variability in length of the β-hairpin region above the active site confers ligand-binding specificity and modulates the catalytic mechanisms within the GH73 family.
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Affiliation(s)
- Alexandra Lipski
- Laboratory for Biocrystallography and Structural Biology of Therapeutic Targets, Molecular and Structural Bases of Infectious Diseases, UMR 5086 CNRS and University of Lyon, 7 passage du Vercors, F-69367 Lyon Cedex 07, France CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Mireille Hervé
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université de Paris-Sud, 91405 Orsay, France
| | - Vincent Lombard
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Didier Nurizzo
- European Synchrotron Radiation Facility, Polygone Scientifique Louis Néel, 6 rue Jules Horowitz, 38000 Grenoble, France
| | - Dominique Mengin-Lecreulx
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619 CNRS, Université de Paris-Sud, 91405 Orsay, France
| | - Yves Bourne
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
| | - Florence Vincent
- CNRS, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France Aix-Marseille University, AFMB UMR7257, 163 avenue de luminy, 13288 Marseille cedex 09, France
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Krawczyk-Balska A, Korsak D, Popowska M. The surface protein Lmo1941 with LysM domain influences cell wall structure and susceptibility of Listeria monocytogenes to cephalosporins. FEMS Microbiol Lett 2014; 357:175-83. [PMID: 24974853 DOI: 10.1111/1574-6968.12518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 06/04/2014] [Accepted: 06/20/2014] [Indexed: 11/30/2022] Open
Abstract
Listeria monocytogenes is a Gram-positive bacterium causing rare but dangerous cases of disease in humans and animals. The β-lactams penicillin G and ampicillin are the antibiotics of choice in the treatment of listeriosis. Recently, lmo1941, encoding a surface protein of L. monocytogenes with unknown function, was identified as a gene transcriptionally upregulated under penicillin G pressure. In this study, the effect of lmo1941 knockout on the susceptibility of L. monocytogenes to β-lactams was examined. Deletion mutant in lmo1941 was constructed and subjected to studies, which revealed that the deletion of lmo1941 had no effect on susceptibility and tolerance to penicillin G and ampicillin but resulted, however, in increased susceptibility of L. monocytogenes to several cephalosporins. Subsequently, the potential effect of lmo1941 mutation on the cell wall of L. monocytogenes was investigated. The analysis revealed quantitative changes in the muropeptide profile of peptidoglycan and a decrease in density of the high-density zone of cell wall of the mutant strain. Both these changes were observed in cells taken from the stationary phase. These results indicate that the surface protein Lmo1941 affects peptidoglycan composition and cell wall structure of L. monocytogenes in the stationary phase of growth.
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Affiliation(s)
- Agata Krawczyk-Balska
- Faculty of Biology, Department of Applied Microbiology, Institute of Microbiology, University of Warsaw, Warsaw, Poland
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Bai XH, Chen HJ, Jiang YL, Wen Z, Huang Y, Cheng W, Li Q, Qi L, Zhang JR, Chen Y, Zhou CZ. Structure of pneumococcal peptidoglycan hydrolase LytB reveals insights into the bacterial cell wall remodeling and pathogenesis. J Biol Chem 2014; 289:23403-16. [PMID: 25002590 DOI: 10.1074/jbc.m114.579714] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Streptococcus pneumoniae causes a series of devastating infections in humans. Previous studies have shown that the endo-β-N-acetylglucosaminidase LytB is critical for pneumococcal cell division and nasal colonization, but the biochemical mechanism of LytB action remains unknown. Here we report the 1.65 Å crystal structure of the catalytic domain (residues Lys-375-Asp-658) of LytB (termed LytBCAT), excluding the choline binding domain. LytBCAT consists of three structurally independent modules: SH3b, WW, and GH73. These modules form a "T-shaped" pocket that accommodates a putative tetrasaccharide-pentapeptide substrate of peptidoglycan. Structural comparison and simulation revealed that the GH73 module of LytB harbors the active site, including the catalytic residue Glu-564. In vitro assays of hydrolytic activity indicated that LytB prefers the peptidoglycan from the lytB-deficient pneumococci, suggesting the existence of a specific substrate of LytB in the immature peptidoglycan. Combined with in vitro cell-dispersing and in vivo cell separation assays, we demonstrated that all three modules are necessary for the optimal activity of LytB. Further functional analysis showed that the full catalytic activity of LytB is required for pneumococcal adhesion to and invasion into human lung epithelial cells. Structure-based alignment indicated that the unique modular organization of LytB is highly conserved in its orthologs from Streptococcus mitis group and Gemella species. These findings provided structural insights into the pneumococcal cell wall remodeling and novel hints for the rational design of therapeutic agents against pneumococcal growth and thereby the related diseases.
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Affiliation(s)
- Xiao-Hui Bai
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Hui-Jie Chen
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Yong-Liang Jiang
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Zhensong Wen
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yubin Huang
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Wang Cheng
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Qiong Li
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Lei Qi
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Yuxing Chen
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
| | - Cong-Zhao Zhou
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China and
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Mesnage S, Dellarole M, Baxter NJ, Rouget JB, Dimitrov JD, Wang N, Fujimoto Y, Hounslow AM, Lacroix-Desmazes S, Fukase K, Foster SJ, Williamson MP. Molecular basis for bacterial peptidoglycan recognition by LysM domains. Nat Commun 2014; 5:4269. [PMID: 24978025 PMCID: PMC4083421 DOI: 10.1038/ncomms5269] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/02/2014] [Indexed: 02/06/2023] Open
Abstract
Carbohydrate recognition is essential for growth, cell adhesion and signalling in all living organisms. A highly conserved carbohydrate binding module, LysM, is found in proteins from viruses, bacteria, fungi, plants and mammals. LysM modules recognize polysaccharides containing N-acetylglucosamine (GlcNAc) residues including peptidoglycan, an essential component of the bacterial cell wall. However, the molecular mechanism underpinning LysM-peptidoglycan interactions remains unclear. Here we describe the molecular basis for peptidoglycan recognition by a multimodular LysM domain from AtlA, an autolysin involved in cell division in the opportunistic bacterial pathogen Enterococcus faecalis. We explore the contribution of individual modules to the binding, identify the peptidoglycan motif recognized, determine the structures of free and bound modules and reveal the residues involved in binding. Our results suggest that peptide stems modulate LysM binding to peptidoglycan. Using these results, we reveal how the LysM module recognizes the GlcNAc-X-GlcNAc motif present in polysaccharides across kingdoms.
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Affiliation(s)
- Stéphane Mesnage
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Mariano Dellarole
- Centre de Biochimie Structurale, CNRS UMR 5048—UM 1—INSERM UMR 1054, F-34090 Montpellier, France
- These authors contributed equally to this work
- Present address: Institut Pasteur, Unité de Virologie Structurale, 28 Rue du Docteur Roux, F-75015 Paris, France
| | - Nicola J. Baxter
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- These authors contributed equally to this work
| | - Jean-Baptiste Rouget
- Centre de Biochimie Structurale, CNRS UMR 5048—UM 1—INSERM UMR 1054, F-34090 Montpellier, France
| | - Jordan D. Dimitrov
- INSERM, U872, Centre de Recherche des Cordeliers, Equipe 16, F-75006 Paris, France
- Université Pierre et Marie Curie, UMR-S 872, F-75006 Paris, France
- Université Paris Descartes, UMR-S 872, F-75006 Paris, France
| | - Ning Wang
- Department of Chemistry, Laboratory for Natural Products Chemistry, Osaka University, Osaka 560-0043, Japan
| | - Yukari Fujimoto
- Department of Chemistry, Laboratory for Natural Products Chemistry, Osaka University, Osaka 560-0043, Japan
| | - Andrea M. Hounslow
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Sébastien Lacroix-Desmazes
- INSERM, U872, Centre de Recherche des Cordeliers, Equipe 16, F-75006 Paris, France
- Université Pierre et Marie Curie, UMR-S 872, F-75006 Paris, France
- Université Paris Descartes, UMR-S 872, F-75006 Paris, France
| | - Koichi Fukase
- Department of Chemistry, Laboratory for Natural Products Chemistry, Osaka University, Osaka 560-0043, Japan
| | - Simon J. Foster
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
| | - Michael P. Williamson
- Krebs Institute, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK
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Carvalho F, Sousa S, Cabanes D. How Listeria monocytogenes organizes its surface for virulence. Front Cell Infect Microbiol 2014; 4:48. [PMID: 24809022 PMCID: PMC4010754 DOI: 10.3389/fcimb.2014.00048] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 04/02/2014] [Indexed: 02/04/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive pathogen responsible for the manifestation of human listeriosis, an opportunistic foodborne disease with an associated high mortality rate. The key to the pathogenesis of listeriosis is the capacity of this bacterium to trigger its internalization by non-phagocytic cells and to survive and even replicate within phagocytes. The arsenal of virulence proteins deployed by L. monocytogenes to successfully promote the invasion and infection of host cells has been progressively unveiled over the past decades. A large majority of them is located at the cell envelope, which provides an interface for the establishment of close interactions between these bacterial factors and their host targets. Along the multistep pathways carrying these virulence proteins from the inner side of the cytoplasmic membrane to their cell envelope destination, a multiplicity of auxiliary proteins must act on the immature polypeptides to ensure that they not only maturate into fully functional effectors but also are placed or guided to their correct position in the bacterial surface. As the major scaffold for surface proteins, the cell wall and its metabolism are critical elements in listerial virulence. Conversely, the crucial physical support and protection provided by this structure make it an ideal target for the host immune system. Therefore, mechanisms involving fine modifications of cell envelope components are activated by L. monocytogenes to render it less recognizable by the innate immunity sensors or more resistant to the activity of antimicrobial effectors. This review provides a state-of-the-art compilation of the mechanisms used by L. monocytogenes to organize its surface for virulence, with special focus on those proteins that work “behind the frontline”, either supporting virulence effectors or ensuring the survival of the bacterium within its host.
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Affiliation(s)
- Filipe Carvalho
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
| | - Sandra Sousa
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
| | - Didier Cabanes
- Group of Molecular Microbiology, Unit of Infection and Immunity, Instituto de Biologia Molecular e Celular, University of Porto Porto, Portugal
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Hendrickx APA, van Schaik W, Willems RJL. The cell wall architecture of Enterococcus faecium: from resistance to pathogenesis. Future Microbiol 2014; 8:993-1010. [PMID: 23902146 DOI: 10.2217/fmb.13.66] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The cell wall of Gram-positive bacteria functions as a surface organelle that continuously interacts with its environment through a plethora of cell wall-associated molecules. Enterococcus faecium is a normal inhabitant of the GI tract of mammals, but has recently become an important etiological agent of hospital-acquired infections in debilitated patients. Insights into the assembly and function of enterococcal cell wall components and their interactions with the host during colonization and infection are essential to explain the worldwide emergence of E. faecium as an important multiantibiotic-resistant nosocomial pathogen. Understanding the biochemistry of cell wall biogenesis and principles of antibiotic resistance at the molecular level may open up new frontiers in research on enterococci, particularly for the development of novel antimicrobial strategies. In this article, we outline the current knowledge on the most important antimicrobial resistance mechanisms that involve peptidoglycan synthesis and the role of cell wall constituents, including lipoteichoic acid, wall teichoic acid, capsular polysaccharides, LPxTG cell wall-anchored surface proteins, WxL-type surface proteins and pili, in the pathogenesis of E. faecium.
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Affiliation(s)
- Antoni P A Hendrickx
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Wong JEMM, Alsarraf HMAB, Kaspersen JD, Pedersen JS, Stougaard J, Thirup S, Blaise M. Cooperative binding of LysM domains determines the carbohydrate affinity of a bacterial endopeptidase protein. FEBS J 2014; 281:1196-208. [PMID: 24355088 DOI: 10.1111/febs.12698] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 12/12/2013] [Accepted: 12/17/2013] [Indexed: 01/01/2023]
Abstract
Cellulose, chitin and peptidoglycan are major long-chain carbohydrates in living organisms, and constitute a substantial fraction of the biomass. Characterization of the biochemical basis of dynamic changes and degradation of these β,1-4-linked carbohydrates is therefore important for both functional studies of biological polymers and biotechnology. Here, we investigated the functional role of multiplicity of the carbohydrate-binding lysin motif (LysM) domain that is found in proteins involved in bacterial peptidoglycan synthesis and remodelling. The Bacillus subtilis peptidoglycan-hydrolysing NlpC/P60 D,L-endopeptidase, cell wall-lytic enzyme associated with cell separation, possesses four LysM domains. The contribution of each LysM domain was determined by direct carbohydrate-binding studies in aqueous solution with microscale thermophoresis. We found that bacterial LysM domains have affinity for N-acetylglucosamine (GlcNac) polymers in the lower-micromolar range. Moreover, we demonstrated that a single LysM domain is able to bind carbohydrate ligands, and that LysM domains act additively to increase the binding affinity. Our study reveals that affinity for GlcNAc polymers correlates with the chain length of the carbohydrate, and suggests that binding of long carbohydrates is mediated by LysM domain cooperativity. We also show that bacterial LysM domains, in contrast to plant LysM domains, do not discriminate between GlcNAc polymers, and recognize both peptidoglycan fragments and chitin polymers with similar affinity. Finally, an Ala replacement study suggested that the carbohydrate-binding site in LysM-containing proteins is conserved across phyla.
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Affiliation(s)
- Jaslyn E M M Wong
- Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Denmark
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The dynamics of peptidoglycan structure and function: conference report on the 3rd Great Wall Symposium. Res Microbiol 2013; 165:60-7. [PMID: 24239960 DOI: 10.1016/j.resmic.2013.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kurushima J, Hayashi I, Sugai M, Tomita H. Bacteriocin protein BacL1 of Enterococcus faecalis is a peptidoglycan D-isoglutamyl-L-lysine endopeptidase. J Biol Chem 2013; 288:36915-25. [PMID: 24235140 DOI: 10.1074/jbc.m113.506618] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Enterococcus faecalis strains are commensal bacteria in humans and other animals, and they are also the causative agent of opportunistic infectious diseases. Bacteriocin 41 (Bac41) is produced by certain E. faecalis clinical isolates, and it is active against other E. faecalis strains. Our genetic analyses demonstrated that the extracellular products of the bacL1 and bacA genes, which are encoded in the Bac41 operon, coordinately express the bacteriocin activity against E. faecalis. In this study, we investigated the molecular functions of the BacL1 and BacA proteins. Immunoblotting and N-terminal amino acid sequence analysis revealed that BacL1 and BacA are secreted without any processing. The coincidental treatment with the recombinant BacL1 and BacA showed complete bacteriocin activity against E. faecalis, but neither BacL1 nor BacA protein alone showed the bacteriocin activity. Interestingly, BacL1 alone demonstrated substantial degrading activity against the cell wall fraction of E. faecalis in the absence of BacA. Furthermore, MALDI-TOF MS analysis revealed that BacL1 has a peptidoglycan D-isoglutamyl-L-lysine endopeptidase activity via a NlpC/P60 homology domain. These results collectively suggest that BacL1 serves as a peptidoglycan hydrolase and, when BacA is present, results in the lysis of viable E. faecalis cells.
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Xu Y, Kong J. Construction and potential application of controlled autolytic systems for Lactobacillus casei in cheese manufacture. J Food Prot 2013; 76:1187-93. [PMID: 23834793 DOI: 10.4315/0362-028x.jfp-12-307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The rapid release of intracellular enzymes into the curd by the autolysis of lactic acid bacteria starters is universally recognized as a critical biological process to accelerate cheese ripening. Lactobacillus casei is typically the dominant nonstarter lactic acid bacterium in the ripening cheese. In this study, two controlled autolytic systems were established in L. casei BL23, based on the exploitation of the autolysins sourced from Lactococcus lactis (AcmA) and Enterococcus faecalis (AtlA). The lysis abilities of the systems were demonstrated both in broth and a model cheese, in which a fivefold increase in lactate dehydrogenase activity was detected in the curd with sufficient viable starter cells being maintained, indicating that they could lead to the timely release of intracellular enzymes.
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Affiliation(s)
- Yi Xu
- State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda South Road, Jinan 250100, People's Republic of China
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Rolain T, Bernard E, Beaussart A, Degand H, Courtin P, Egge-Jacobsen W, Bron PA, Morsomme P, Kleerebezem M, Chapot-Chartier MP, Dufrêne YF, Hols P. O-glycosylation as a novel control mechanism of peptidoglycan hydrolase activity. J Biol Chem 2013; 288:22233-47. [PMID: 23760506 DOI: 10.1074/jbc.m113.470716] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Acm2, the major autolysin of Lactobacillus plantarum, is a tripartite protein. Its catalytic domain is surrounded by an O-glycosylated N-terminal region rich in Ala, Ser, and Thr (AST domain), which is of low complexity and unknown function, and a C-terminal region composed of five SH3b peptidoglycan (PG) binding domains. Here, we investigate the contribution of these two accessory domains and of O-glycosylation to Acm2 functionality. We demonstrate that Acm2 is an N-acetylglucosaminidase and identify the pattern of O-glycosylation (21 mono-N-acetylglucosamines) of its AST domain. The O-glycosylation process is species-specific as Acm2 purified from Lactococcus lactis is not glycosylated. We therefore explored the functional role of O-glycosylation by purifying different truncated versions of Acm2 that were either glycosylated or non-glycosylated. We show that SH3b domains are able to bind PG and are responsible for Acm2 targeting to the septum of dividing cells, whereas the AST domain and its O-glycosylation are not involved in this process. Notably, our data reveal that the lack of O-glycosylation of the AST domain significantly increases Acm2 enzymatic activity, whereas removal of SH3b PG binding domains dramatically reduces this activity. Based on this antagonistic role, we propose a model in which access of the Acm2 catalytic domain to its substrate may be hindered by the AST domain where O-glycosylation changes its conformation and/or mediates interdomain interactions. To the best of our knowledge, this is the first time that O-glycosylation is shown to control the activity of a bacterial enzyme.
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Affiliation(s)
- Thomas Rolain
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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Enterococcus faecium biofilm formation: identification of major autolysin AtlAEfm, associated Acm surface localization, and AtlAEfm-independent extracellular DNA Release. mBio 2013; 4:e00154. [PMID: 23592262 PMCID: PMC3634606 DOI: 10.1128/mbio.00154-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Enterococcus faecium is an important multidrug-resistant nosocomial pathogen causing biofilm-mediated infections in patients with medical devices. Insight into E. faecium biofilm pathogenesis is pivotal for the development of new strategies to prevent and treat these infections. In several bacteria, a major autolysin is essential for extracellular DNA (eDNA) release in the biofilm matrix, contributing to biofilm attachment and stability. In this study, we identified and functionally characterized the major autolysin of E. faecium E1162 by a bioinformatic genome screen followed by insertional gene disruption of six putative autolysin genes. Insertional inactivation of locus tag EfmE1162_2692 resulted in resistance to lysis, reduced eDNA release, deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and significant chaining compared to that of the wild type. Therefore, locus tag EfmE1162_2692 was considered the major autolysin in E. faecium and renamed atlAEfm. In addition, AtlAEfm was implicated in cell surface exposure of Acm, a virulence factor in E. faecium, and thereby facilitates binding to collagen types I and IV. This is a novel feature of enterococcal autolysins not described previously. Furthermore, we identified (and localized) autolysin-independent DNA release in E. faecium that contributes to cell-cell interactions in the atlAEfm mutant and is important for cell separation. In conclusion, AtlAEfm is the major autolysin in E. faecium and contributes to biofilm stability and Acm localization, making AtlAEfm a promising target for treatment of E. faecium biofilm-mediated infections. Nosocomial infections caused by Enterococcus faecium have rapidly increased, and treatment options have become more limited. This is due not only to increasing resistance to antibiotics but also to biofilm-associated infections. DNA is released in biofilm matrix via cell lysis, caused by autolysin, and acts as a matrix stabilizer. In this study, we identified and characterized the major autolysin in E. faecium, which we designated AtlAEfm. atlAEfm disruption resulted in resistance to lysis, reduced extracellular DNA (eDNA), deficient cell attachment, decreased biofilm, decreased cell wall hydrolysis, and chaining. Furthermore, AtlAEfm is associated with Acm cell surface localization, resulting in less binding to collagen types I and IV in the atlAEfm mutant. We also identified AtlAEfm-independent eDNA release that contributes to cell-cell interactions in the atlAEfm mutant. These findings indicate that AtlAEfm is important in biofilm and collagen binding in E. faecium, making AtlAEfm a promising target for treatment of E. faecium infections.
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Kariu T, Yang X, Marks CB, Zhang X, Pal U. Proteolysis of BB0323 results in two polypeptides that impact physiologic and infectious phenotypes in Borrelia burgdorferi. Mol Microbiol 2013; 88:510-22. [PMID: 23489252 DOI: 10.1111/mmi.12202] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2013] [Indexed: 01/12/2023]
Abstract
Borrelia burgdorferi gene product BB0323 is required for cell fission and pathogen persistence in vivo. Here, we show that BB0323, which is conserved among globally prevalent infectious strains, supports normal spirochaete growth and morphology even at early phases of cell division. We demonstrate that native BB0323 undergoes proteolytic processing at the C-terminus, at a site after the first 202 N-terminal amino acids. We further identified a periplasmic BB0323 binding protein in B. burgdorferi, annotated as BB0104, having serine protease activity responsible for the primary cleavage of BB0323 to produce discrete N- and C-terminal polypeptides. These two BB0323 polypeptides interact with each other, and either individually or as a complex, are associated with multiple functions in spirochaete biology and infectivity. While N-terminal BB0323 is adequate to support cell fission, the C-terminal LysM domain is dispensable for this process, despite its ability to bind B. burgdorferi peptidoglycan. However, the LysM domain or the precisely processed BB0323 product is essential for mammalian infection. As BB0323 is a membrane protein crucial for B. burgdorferi survival in vivo, exploring its function may suggest novel ways to interrupt infection while enhancing our understanding of the intricate spirochaete fission process.
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Affiliation(s)
- Toru Kariu
- Department of Veterinary Medicine and Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA
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