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Olczak T, Śmiga M, Antonyuk SV, Smalley JW. Hemophore-like proteins of the HmuY family in the oral and gut microbiome: unraveling the mystery of their evolution. Microbiol Mol Biol Rev 2024; 88:e0013123. [PMID: 38305743 PMCID: PMC10966948 DOI: 10.1128/mmbr.00131-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024] Open
Abstract
SUMMARY Heme (iron protoporphyrin IX, FePPIX) is the main source of iron and PPIX for host-associated pathogenic bacteria, including members of the Bacteroidota (formerly Bacteroidetes) phylum. Porphyromonas gingivalis, a keystone oral pathogen, uses a unique heme uptake (Hmu) system, comprising a hemophore-like protein, designated as the first member of the novel HmuY family. Compared to classical, secreted hemophores utilized by Gram-negative bacteria or near-iron transporter domain-based hemophores utilized by Gram-positive bacteria, the HmuY family comprises structurally similar proteins that have undergone diversification during evolution. The best characterized are P. gingivalis HmuY and its homologs from Tannerella forsythia (Tfo), Prevotella intermedia (PinO and PinA), Bacteroides vulgatus (Bvu), and Bacteroides fragilis (BfrA, BfrB, and BfrC). In contrast to the two histidine residues coordinating heme iron in P. gingivalis HmuY, Tfo, PinO, PinA, Bvu, and BfrA preferentially use two methionine residues. Interestingly, BfrB, despite conserved methionine residue, binds the PPIX ring without iron coordination. BfrC binds neither heme nor PPIX in keeping with the lack of conserved histidine or methionine residues used by other members of the HmuY family. HmuY competes for heme binding and heme sequestration from host hemoproteins with other members of the HmuY family to increase P. gingivalis competitiveness. The participation of HmuY in the host immune response confirms its relevance in relation to the survival of P. gingivalis and its ability to induce dysbiosis not only in the oral microbiome but also in the gut microbiome or other host niches, leading to local injuries and involvement in comorbidities.
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Affiliation(s)
- Teresa Olczak
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Michał Śmiga
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | - Svetlana V. Antonyuk
- Molecular Biophysics Group, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, the University of Liverpool, Liverpool, United Kingdom
| | - John W. Smalley
- Institute of Life Course and Medical Sciences, School of Dentistry, the University of Liverpool, Liverpool, United Kingdom
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2
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Ouyang P, Yang J, Zhong Q, Yuan Y, Gao Y, Wang H, Yang ST. Toxicity of VO 2 micro/nanoparticles to nitrogen-fixing bacterium Azotobacter vinelandii. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133553. [PMID: 38266589 DOI: 10.1016/j.jhazmat.2024.133553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/06/2024] [Accepted: 01/16/2024] [Indexed: 01/26/2024]
Abstract
Vanadium dioxide (VO2) has been used in a variety of products due to its outstanding phase transition properties. However, as potential heavy metal contaminants, the environmental hazards and risks of VO2 should be systematically investigated. Biological nitrogen fixation is one of the most dominant processes in biogeochemical cycle, which is associated with nitrogen-fixing bacteria. In this study, we reported the environmental bio-effects of VO2 micro/nanoparticles on the nitrogen-fixing bacterium Azotobacter vinelandii. VO2 at 10 and 30 mg/L caused severe hazards to A. vinelandii, such as cell apoptosis, oxidative damage, physical damage, genotoxicity, and the loss of nitrogen fixation activity. The up-regulated differentially expressed genes of A. vinelandii were related to stress response, and the down-regulated genes were mainly related to energy metabolism. Surprisingly, VO2 of 10 mg/L decreased the nif gene expression but elevated the vnf gene expression, which enhanced the ability of A. vinelandii to reduce acetylene in anaerobic environment. In addition, under tested conditions, VO2 nanoparticles exhibited insignificantly higher toxicity than VO2 microparticles.
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Affiliation(s)
- Peng Ouyang
- Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China; College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Jinwei Yang
- Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China
| | - Qinmei Zhong
- Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China
| | - Yue Yuan
- Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China
| | - Yanfeng Gao
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Haifang Wang
- Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444, China.
| | - Sheng-Tao Yang
- Key Laboratory of Pollution Control Chemistry and Environmental Functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission, Key Laboratory of General Chemistry of the National Ethnic Affairs Commission, School of Chemistry and Environment, Southwest Minzu University, Chengdu 610041, China.
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3
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Hussein SM, Sofoluwe A, Paleja A, Duhme-Klair A, Thomas MS. Identification of a system for hydroxamate xenosiderophore-mediated iron transport in Burkholderia cenocepacia. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001425. [PMID: 38189440 PMCID: PMC10866019 DOI: 10.1099/mic.0.001425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/19/2023] [Indexed: 01/09/2024]
Abstract
One of the mechanisms employed by the opportunistic pathogen Burkholderia cenocepacia to acquire the essential element iron is the production and release of two ferric iron chelating compounds (siderophores), ornibactin and pyochelin. Here we show that B. cenocepacia is also able to take advantage of a range of siderophores produced by other bacteria and fungi ('xenosiderophores') that chelate iron exclusively by means of hydroxamate groups. These include the tris-hydroxamate siderophores ferrioxamine B, ferrichrome, ferricrocin and triacetylfusarinine C, the bis-hydroxamates alcaligin and rhodotorulic acid, and the monohydroxamate siderophore cepabactin. We also show that of the 24 TonB-dependent transporters encoded by the B. cenocepacia genome, two (FhuA and FeuA) are involved in the uptake of hydroxamate xenosiderophores, with FhuA serving as the exclusive transporter of iron-loaded ferrioxamine B, triacetylfusarinine C, alcaligin and rhodotorulic acid, while both FhuA and FeuA are able to translocate ferrichrome-type siderophores across the outer membrane. Finally, we identified FhuB, a putative cytoplasmic membrane-anchored ferric-siderophore reductase, as being obligatory for utilization of all of the tested bis- and tris-hydroxamate xenosiderophores apart from alcaligin.
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Affiliation(s)
- Syakira Mohammed Hussein
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
| | - Aderonke Sofoluwe
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
- Department of Immunobiology, School of Immunology & Microbial Sciences, King’s College London, London WC2R 2LS, UK
| | - Ameya Paleja
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
| | - Anne Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Mark S. Thomas
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
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4
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Lenoir C, Pelletier A, Manuse S, Millat H, Ducret A, Galinier A, Doan T, Grangeasse C. The morphogenic protein CopD controls the spatio-temporal dynamics of PBP1a and PBP2b in Streptococcus pneumoniae. mBio 2023; 14:e0141123. [PMID: 37728370 PMCID: PMC10653890 DOI: 10.1128/mbio.01411-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/25/2023] [Indexed: 09/21/2023] Open
Abstract
IMPORTANCE Penicillin-binding proteins (PBPs) are essential for proper bacterial cell division and morphogenesis. The genome of Streptococcus pneumoniae encodes for two class B PBPs (PBP2x and 2b), which are required for the assembly of the peptidoglycan framework and three class A PBPs (PBP1a, 1b and 2a), which remodel the peptidoglycan mesh during cell division. Therefore, their activities should be finely regulated in space and time to generate the pneumococcal ovoid cell shape. To date, two proteins, CozE and MacP, are known to regulate the function of PBP1a and PBP2a, respectively. In this study, we describe a novel regulator (CopD) that acts on both PBP1a and PBP2b. These findings provide valuable information for understanding bacterial cell division. Furthermore, knowing that ß-lactam antibiotic resistance often arises from PBP mutations, the characterization of such a regulator represents a promising opportunity to develop new strategies to resensitize resistant strains.
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Affiliation(s)
- Cassandra Lenoir
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
| | - Anaïs Pelletier
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
| | - Sylvie Manuse
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
| | - Hugo Millat
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
| | - Adrien Ducret
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne, UMR, Aix-Marseille Université, CNRS, Marseille, France
| | - Thierry Doan
- Laboratoire d’Ingénierie des Systèmes Macromoléculaires, UMR, Aix-Marseille Université, Marseille, France
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, UMR, Université de Lyon, CNRS, Lyon, France
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5
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Brogan AP, Habib C, Hobbs SJ, Kranzusch PJ, Rudner DZ. Bacterial SEAL domains undergo autoproteolysis and function in regulated intramembrane proteolysis. Proc Natl Acad Sci U S A 2023; 120:e2310862120. [PMID: 37756332 PMCID: PMC10556640 DOI: 10.1073/pnas.2310862120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Gram-positive bacteria use SigI/RsgI-family sigma factor/anti-sigma factor pairs to sense and respond to cell wall defects and plant polysaccharides. In Bacillus subtilis, this signal transduction pathway involves regulated intramembrane proteolysis (RIP) of the membrane-anchored anti-sigma factor RsgI. However, unlike most RIP signaling pathways, site-1 cleavage of RsgI on the extracytoplasmic side of the membrane is constitutive and the cleavage products remain stably associated, preventing intramembrane proteolysis. The regulated step in this pathway is their dissociation, which is hypothesized to involve mechanical force. Release of the ectodomain enables intramembrane cleavage by the RasP site-2 protease and activation of SigI. The constitutive site-1 protease has not been identified for any RsgI homolog. Here, we report that RsgI's extracytoplasmic domain has structural and functional similarities to eukaryotic SEA domains that undergo autoproteolysis and have been implicated in mechanotransduction. We show that site-1 proteolysis in B. subtilis and Clostridial RsgI family members is mediated by enzyme-independent autoproteolysis of these SEA-like domains. Importantly, the site of proteolysis enables retention of the ectodomain through an undisrupted β-sheet that spans the two cleavage products. Autoproteolysis can be abrogated by relief of conformational strain in the scissile loop, in a mechanism analogous to eukaryotic SEA domains. Collectively, our data support the model that RsgI-SigI signaling is mediated by mechanotransduction in a manner that has striking parallels with eukaryotic mechanotransducive signaling pathways.
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Affiliation(s)
- Anna P. Brogan
- Department of Microbiology, Harvard Medical School, Boston, MA02115
| | - Cameron Habib
- Department of Microbiology, Harvard Medical School, Boston, MA02115
| | - Samuel J. Hobbs
- Department of Microbiology, Harvard Medical School, Boston, MA02115
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA02115
| | - Philip J. Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA02115
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA02115
| | - David Z. Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA02115
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6
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Nwankwo C, Hou J, Cui HL. Extracellular proteases from halophiles: diversity and application challenges. Appl Microbiol Biotechnol 2023; 107:5923-5934. [PMID: 37566160 DOI: 10.1007/s00253-023-12721-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023]
Abstract
Halophilic extracellular proteases offer promising application in various fields. Information on these prominent proteins including the synthesizing organisms, biochemical properties, domain organisation, purification, and application challenges has never been covered in recent reviews. Although extracellular proteases from bacteria pioneered the study of proteases in halophiles, progress is being made in proteases from halophilic archaea. Recent advances in extracellular proteases from archaea revealed that archaeal proteases are more robust and applicable. Extracellular proteases are composed of domains that determine their mechanisms of action. The intriguing domain structure of halophilic extracellular proteases consists of N-terminal domain, catalytic domain, and C-terminal extension. The role of C-terminal domains varies among different organisms. A high diversity of C-terminal domains would endow the proteases with diverse functions. With the development of genomics, culture-independent methods involving heterologous expression, affinity chromatography, and in vitro refolding are deployed with few challenges on purification and presenting novel research opportunities. Halophilic extracellular proteases have demonstrated remarkable potentials in industries such as detergent, leather, peptide synthesis, and biodegradation, with desirable properties and ability to withstand harsh industrial processes. KEY POINTS: • Halophilic extracellular proteases have robust properties suitable for applications. • A high diversity of C-terminal domains may endow proteases with diverse properties. • Novel protease extraction methods present novel application opportunities.
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Affiliation(s)
- Chidiebele Nwankwo
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Jingkou District, Zhenjiang, 212013, Jiangsu, People's Republic of China
- Natural Sciences Unit, School of General Studies, University of Nigeria, Nsukka, 410002, Enugu State, Nigeria
- Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, 410002, Enugu State, Nigeria
| | - Jing Hou
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Jingkou District, Zhenjiang, 212013, Jiangsu, People's Republic of China.
| | - Heng-Lin Cui
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Jingkou District, Zhenjiang, 212013, Jiangsu, People's Republic of China.
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7
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Brogan AP, Habib C, Hobbs SJ, Kranzusch PJ, Rudner DZ. Bacterial SEAL domains undergo autoproteolysis and function in regulated intramembrane proteolysis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.27.546760. [PMID: 37425962 PMCID: PMC10327162 DOI: 10.1101/2023.06.27.546760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Gram-positive bacteria use SigI/RsgI-family sigma factor/anti-sigma factor pairs to sense and respond to cell wall defects and plant polysaccharides. In Bacillus subtilis this signal transduction pathway involves regulated intramembrane proteolysis (RIP) of the membrane-anchored anti-sigma factor RsgI. However, unlike most RIP signaling pathways, site-1 cleavage of RsgI on the extracytoplasmic side of the membrane is constitutive and the cleavage products remain stably associated, preventing intramembrane proteolysis. The regulated step in this pathway is their dissociation, which is hypothesized to involve mechanical force. Release of the ectodomain enables intramembrane cleavage by the RasP site-2 protease and activation of SigI. The constitutive site-1 protease has not been identified for any RsgI homolog. Here, we report that RsgI's extracytoplasmic domain has structural and functional similarities to eukaryotic SEA domains that undergo autoproteolysis and have been implicated in mechanotransduction. We show that site-1 proteolysis in B. subtilis and Clostridial RsgI family members is mediated by enzyme-independent autoproteolysis of these SEA-like (SEAL) domains. Importantly, the site of proteolysis enables retention of the ectodomain through an undisrupted ß-sheet that spans the two cleavage products. Autoproteolysis can be abrogated by relief of conformational strain in the scissile loop, in a mechanism analogous to eukaryotic SEA domains. Collectively, our data support the model that RsgI-SigI signaling is mediated by mechanotransduction in a manner that has striking parallels with eukaryotic mechanotransducive signaling pathways. SIGNIFICANCE SEA domains are broadly conserved among eukaryotes but absent in bacteria. They are present on diverse membrane-anchored proteins some of which have been implicated in mechanotransducive signaling pathways. Many of these domains have been found to undergo autoproteolysis and remain noncovalently associated following cleavage. Their dissociation requires mechanical force. Here, we identify a family of bacterial SEA-like (SEAL) domains that arose independently from their eukaryotic counterparts but have structural and functional similarities. We show these SEAL domains autocleave and the cleavage products remain stably associated. Importantly, these domains are present on membrane-anchored anti-sigma factors that have been implicated in mechanotransduction pathways analogous to those in eukaryotes. Our findings suggest that bacterial and eukaryotic signaling systems have evolved a similar mechanism to transduce mechanical stimuli across the lipid bilayer.
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Affiliation(s)
- Anna P. Brogan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Cameron Habib
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Samuel J. Hobbs
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115
| | - Philip J. Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115
| | - David Z. Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
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8
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Ong A, O’Brian MR. The Bradyrhizobium japonicum fsrB gene is essential for utilization of structurally diverse ferric siderophores to fulfill its nutritional iron requirement. Mol Microbiol 2023; 119:340-349. [PMID: 36648393 PMCID: PMC10411499 DOI: 10.1111/mmi.15028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/18/2023]
Abstract
In Bradyrhizobium japonicum, iron uptake from ferric siderophores involves selective outer membrane proteins and non-selective periplasmic and cytoplasmic membrane components that accommodate numerous structurally diverse siderophores. Free iron traverses the cytoplasmic membrane through the ferrous (Fe2+ ) transporter system FeoAB, but the other non-selective components have not been described. Here, we identify fsrB as an iron-regulated gene required for growth on iron chelates of catecholate- and hydroxymate-type siderophores, but not on inorganic iron. Utilization of the non-physiological iron chelator EDDHA as an iron source was also dependent on fsrB. Uptake activities of 55 Fe3+ bound to ferrioxamine B, ferrichrome or enterobactin were severely diminished in the fsrB mutant compared with the wild type. Growth of the fsrB or feoB strains on ferrichrome were rescued with plasmid-borne E. coli fhuCDB ferrichrome transport genes, suggesting that FsrB activity occurs in the periplasm rather than the cytoplasm. Whole cells of an fsrB mutant are defective in ferric reductase activity. Both whole cells and spheroplasts catalyzed the demetallation of ferric siderophores that were defective in an fsrB mutant. Collectively, the data support a model whereby FsrB is required for reduction of iron and its dissociation from the siderophore in the periplasm, followed by transport of the ferrous ion into the cytoplasm by FeoAB.
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Affiliation(s)
- Alasteir Ong
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, 955 Main Street, Room 4102, Buffalo, New York 14203-1121
| | - Mark R. O’Brian
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, The University at Buffalo, 955 Main Street, Room 4102, Buffalo, New York 14203-1121
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9
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Hemmann JL, Keller P, Hemmerle L, Vonderach T, Ochsner AM, Bortfeld-Miller M, Günther D, Vorholt JA. Lanpepsy is a novel lanthanide-binding protein involved in the lanthanide response of the obligate methylotroph Methylobacillus flagellatus. J Biol Chem 2023; 299:102940. [PMID: 36702252 PMCID: PMC9988556 DOI: 10.1016/j.jbc.2023.102940] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
Lanthanides were recently discovered as metals required in the active site of certain methanol dehydrogenases. Since then, the characterization of the lanthanome, that is, proteins involved in sensing, uptake, and utilization of lanthanides, has become an active field of research. Initial exploration of the response to lanthanides in methylotrophs has revealed that the lanthanome is not conserved and that multiple mechanisms for lanthanide utilization must exist. Here, we investigated the lanthanome in the obligate model methylotroph Methylobacillus flagellatus. We used a proteomic approach to analyze differentially regulated proteins in the presence of lanthanum. While multiple known proteins showed induction upon growth in the presence of lanthanum (Xox proteins, TonB-dependent receptor), we also identified several novel proteins not previously associated with lanthanide utilization. Among these was Mfla_0908, a periplasmic 19 kDa protein without functional annotation. The protein comprises two characteristic PepSY domains, which is why we termed the protein lanpepsy (LanP). Based on bioinformatic analysis, we speculated that LanP could be involved in lanthanide binding. Using dye competition assays, quantification of protein-bound lanthanides by inductively coupled plasma mass spectrometry, as well as isothermal titration calorimetry, we demonstrated the presence of multiple lanthanide binding sites that showed selectivity over the chemically similar calcium ion. LanP thus represents the first member of the PepSY family that binds lanthanides. Although the physiological role of LanP is still unclear, its identification is of interest for applications toward the sustainable purification and separation of rare-earth elements.
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Affiliation(s)
- Jethro L Hemmann
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
| | - Philipp Keller
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Lucas Hemmerle
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Thomas Vonderach
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Andrea M Ochsner
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | | | - Detlef Günther
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland.
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10
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Scheithauer L, Karagöz MS, Mayer BE, Steinert M. Protein sociology of ProA, Mip and other secreted virulence factors at the Legionella pneumophila surface. Front Cell Infect Microbiol 2023; 13:1140688. [PMID: 36936764 PMCID: PMC10017501 DOI: 10.3389/fcimb.2023.1140688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
The pathogenicity of L. pneumophila, the causative agent of Legionnaires' disease, depends on an arsenal of interacting proteins. Here we describe how surface-associated and secreted virulence factors of this pathogen interact with each other or target extra- and intracellular host proteins resulting in host cell manipulation and tissue colonization. Since progress of computational methods like AlphaFold, molecular dynamics simulation, and docking allows to predict, analyze and evaluate experimental proteomic and interactomic data, we describe how the combination of these approaches generated new insights into the multifaceted "protein sociology" of the zinc metalloprotease ProA and the peptidyl-prolyl cis/trans isomerase Mip (macrophage infectivity potentiator). Both virulence factors of L. pneumophila interact with numerous proteins including bacterial flagellin (FlaA) and host collagen, and play important roles in virulence regulation, host tissue degradation and immune evasion. The recent progress in protein-ligand analyses of virulence factors suggests that machine learning will also have a beneficial impact in early stages of drug discovery.
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Affiliation(s)
- Lina Scheithauer
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Mustafa Safa Karagöz
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Benjamin E. Mayer
- Computational Biology & Simulation, Technische Universität Darmstadt, Darmstadt, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Michael Steinert,
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11
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Liu Y, Gao J, Wang N, Li X, Fang N, Zhuang X. Diffusible signal factor enhances the saline-alkaline resistance and rhizosphere colonization of Stenotrophomonas rhizophila by coordinating optimal metabolism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155403. [PMID: 35469877 DOI: 10.1016/j.scitotenv.2022.155403] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 06/14/2023]
Abstract
Quorum sensing (QS) regulates various physiological processes in a cell density-dependent mode via cell-cell communication. Stenotrophomonas rhizophila DSM14405T having the diffusible signal factor (DSF)-QS system, is a plant growth-promoting rhizobacteria (PGPR) that enables host plants to tolerate saline-alkaline stress. However, the regulatory mechanism of DSF-QS in S. rhizophila is not fully understood. In this study, we used S. rhizophila DSM14405T wild-type (WT) and an incompetent DSF production rpfF-knockout mutant to explore the regulatory role of QS in S. rhizophila growth, stress responses, biofilm formation, and colonization under saline-alkaline stress. We found that a lack of DSF-QS reduces the tolerance of S. rhizosphere ΔrpfF to saline-alkaline stress, with a nearly 25-fold reduction in the ΔrpfF population compared with WT at 24 h under stress. Transcriptome analysis revealed that QS helps S. rhizophila WT respond to saline-alkaline stress by enhancing metabolism associated with the cell wall and membrane, oxidative stress response, cell adhesion, secretion systems, efflux pumps, and TonB systems. These metabolic systems enhance penetration defense, Na+ efflux, iron uptake, and reactive oxygen species scavenging. Additionally, the absence of DSF-QS causes overexpression of biofilm-associated genes under the regulation of sigma 54 and other transcriptional regulators. However, greater biofilm formation capacity confers no advantage on S. rhizosphere ΔrpfF in rhizosphere colonization. Altogether, our results show the importance of QS in PGPR growth and colonization; QS gives PGPR a collective adaptive advantage in harsh natural environments.
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Affiliation(s)
- Ying Liu
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Life Sciences, Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Jie Gao
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Wang
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianglong Li
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Na Fang
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Institute of International Rivers and Eco-security, Yunan University, Kunming 650500, China
| | - Xuliang Zhuang
- CAS Key Laboratory of Environment Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
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12
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Gallois N, Alpha-Bazin B, Bremond N, Ortet P, Barakat M, Piette L, Mohamad Ali A, Lemaire D, Legrand P, Theodorakopoulos N, Floriani M, Février L, Den Auwer C, Arnoux P, Berthomieu C, Armengaud J, Chapon V. Discovery and characterization of UipA, a uranium- and iron-binding PepSY protein involved in uranium tolerance by soil bacteria. THE ISME JOURNAL 2022; 16:705-716. [PMID: 34556817 PMCID: PMC8857325 DOI: 10.1038/s41396-021-01113-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 09/01/2021] [Accepted: 09/08/2021] [Indexed: 02/08/2023]
Abstract
Uranium is a naturally occurring radionuclide. Its redistribution, primarily due to human activities, can have adverse effects on human and non-human biota, which poses environmental concerns. The molecular mechanisms of uranium tolerance and the cellular response induced by uranium exposure in bacteria are not yet fully understood. Here, we carried out a comparative analysis of four actinobacterial strains isolated from metal and radionuclide-rich soils that display contrasted uranium tolerance phenotypes. Comparative proteogenomics showed that uranyl exposure affects 39-47% of the total proteins, with an impact on phosphate and iron metabolisms and membrane proteins. This approach highlighted a protein of unknown function, named UipA, that is specific to the uranium-tolerant strains and that had the highest positive fold-change upon uranium exposure. UipA is a single-pass transmembrane protein and its large C-terminal soluble domain displayed a specific, nanomolar binding affinity for UO22+ and Fe3+. ATR-FTIR and XAS-spectroscopy showed that mono and bidentate carboxylate groups of the protein coordinated both metals. The crystal structure of UipA, solved in its apo state and bound to uranium, revealed a tandem of PepSY domains in a swapped dimer, with a negatively charged face where uranium is bound through a set of conserved residues. This work reveals the importance of UipA and its PepSY domains in metal binding and radionuclide tolerance.
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Affiliation(s)
- Nicolas Gallois
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Béatrice Alpha-Bazin
- grid.5583.b0000 0001 2299 8025Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, 30200 Bagnols-sur-Cèze, France
| | - Nicolas Bremond
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Philippe Ortet
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Mohamed Barakat
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Laurie Piette
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Abbas Mohamad Ali
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - David Lemaire
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Pierre Legrand
- grid.426328.9Synchrotron SOLEIL. L’Orme des Merisiers Saint-Aubin. BP 48, 91192 Gif-sur-Yvette, France
| | - Nicolas Theodorakopoulos
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France ,grid.418735.c0000 0001 1414 6236IRSN, PSE-ENV/SRTE/LR2T, B.P. 3, 13115 Saint Paul-lez-Durance, Cedex France
| | - Magali Floriani
- grid.418735.c0000 0001 1414 6236IRSN, PSE-ENV/SRTE/LECO, B.P. 3, 13115 Saint Paul-lez-Durance, Cedex France
| | - Laureline Février
- grid.418735.c0000 0001 1414 6236IRSN, PSE-ENV/SRTE/LR2T, B.P. 3, 13115 Saint Paul-lez-Durance, Cedex France
| | - Christophe Den Auwer
- grid.462124.70000 0004 0384 8488Université Côte d’Azur, CNRS, ICN, 06108 Nice, France
| | - Pascal Arnoux
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Catherine Berthomieu
- grid.5399.60000 0001 2176 4817Aix Marseille Université, CEA, CNRS, BIAM, 13108 Saint Paul-Lez-Durance, France
| | - Jean Armengaud
- grid.5583.b0000 0001 2299 8025Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, 30200 Bagnols-sur-Cèze, France
| | - Virginie Chapon
- Aix Marseille Université, CEA, CNRS, BIAM, 13108, Saint Paul-Lez-Durance, France.
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13
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Cheng JH, Zhang XY, Wang Z, Zhang X, Liu SC, Song XY, Zhang YZ, Ding JM, Chen XL, Xu F. Potential of Thermolysin-like Protease A69 in Preparation of Bovine Collagen Peptides with Moisture-Retention Ability and Antioxidative Activity. Mar Drugs 2021; 19:md19120676. [PMID: 34940675 PMCID: PMC8708487 DOI: 10.3390/md19120676] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/18/2021] [Accepted: 11/25/2021] [Indexed: 12/28/2022] Open
Abstract
Bovine bone is rich in collagen and is a good material for collagen peptide preparation. Although thermolysin-like proteases (TLPs) have been applied in different fields, the potential of TLPs in preparing bioactive collagen peptides has rarely been evaluated. Here, we characterized a thermophilic TLP, A69, from a hydrothermal bacterium Anoxybacillus caldiproteolyticus 1A02591, and evaluated its potential in preparing bioactive collagen peptides. A69 showed the highest activity at 60 °C and pH 7.0. We optimized the conditions for bovine bone collagen hydrolysis and set up a process with high hydrolysis efficiency (99.4%) to prepare bovine bone collagen peptides, in which bovine bone collagen was hydrolyzed at 60 °C for 2 h with an enzyme-substrate ratio of 25 U/g. The hydrolysate contained 96.5% peptides that have a broad molecular weight distribution below 10000 Da. The hydrolysate showed good moisture-retention ability and a high hydroxyl radical (•OH) scavenging ratio of 73.2%, suggesting that the prepared collagen peptides have good antioxidative activity. Altogether, these results indicate that the thermophilic TLP A69 has promising potential in the preparation of bioactive collagen peptides, which may have potentials in cosmetics, food and pharmaceutical industries. This study lays a foundation for the high-valued utilization of bovine bone collagen.
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Affiliation(s)
- Jun-Hui Cheng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China;
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Xiao-Yu Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Zhen Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Xia Zhang
- Department of Molecular Biology, Qingdao Vland Biotech Inc., Qingdao 266102, China; (X.Z.); (S.-C.L.)
| | - Shi-Cheng Liu
- Department of Molecular Biology, Qingdao Vland Biotech Inc., Qingdao 266102, China; (X.Z.); (S.-C.L.)
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Yu-Zhong Zhang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China;
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Jun-Mei Ding
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, China
- Correspondence: (J.-M.D.); (X.-L.C.); (F.X.)
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Correspondence: (J.-M.D.); (X.-L.C.); (F.X.)
| | - Fei Xu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; (J.-H.C.); (X.-Y.Z.); (Z.W.); (X.-Y.S.)
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Correspondence: (J.-M.D.); (X.-L.C.); (F.X.)
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14
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Structural insights into a novel family of integral membrane siderophore reductases. Proc Natl Acad Sci U S A 2021; 118:2101952118. [PMID: 34417315 DOI: 10.1073/pnas.2101952118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gram-negative bacteria take up the essential ion Fe3+ as ferric-siderophore complexes through their outer membrane using TonB-dependent transporters. However, the subsequent route through the inner membrane differs across many bacterial species and siderophore chemistries and is not understood in detail. Here, we report the crystal structure of the inner membrane protein FoxB (from Pseudomonas aeruginosa) that is involved in Fe-siderophore uptake. The structure revealed a fold with two tightly bound heme molecules. In combination with in vitro reduction assays and in vivo iron uptake studies, these results establish FoxB as an inner membrane reductase involved in the release of iron from ferrioxamine during Fe-siderophore uptake.
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15
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Delisle J, Cordier B, Audebert S, Pophillat M, Cluzel C, Espinosa L, Grangeasse C, Galinier A, Doan T. Characterization of TseB: A new actor in cell wall elongation in Bacillus subtilis. Mol Microbiol 2021; 116:1099-1112. [PMID: 34411374 DOI: 10.1111/mmi.14798] [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: 02/26/2021] [Revised: 08/16/2021] [Accepted: 08/16/2021] [Indexed: 11/30/2022]
Abstract
Penicillin-binding proteins (PBPs) are crucial enzymes of peptidoglycan assembly and targets of β-lactam antibiotics. However, little is known about their regulation. Recently, membrane proteins were shown to regulate the bifunctional transpeptidases/glycosyltransferases aPBPs in some bacteria. However, up to now, regulators of monofunctional transpeptidases bPBPs have yet to be revealed. Here, we propose that TseB could be such a PBP regulator. This membrane protein was previously found to suppress tetracycline sensitivity of a Bacillus subtilis strain deleted for ezrA, a gene encoding a regulator of septation ring formation. In this study, we show that TseB is required for B. subtilis normal cell shape, tseB mutant cells being shorter and wider than wild-type cells. We observed that TseB interacts with PBP2A, a monofunctional transpeptidase. While TseB is not required for PBP2A activity, stability, and localization, we show that the overproduction of PBP2A is deleterious in the absence of TseB. In addition, we showed that TseB is necessary not only for efficient cell wall elongation during exponential phase but also during spore outgrowth, as it was also observed for PBP2A. Altogether, our results suggest that TseB is a new member of the elongasome that regulates PBP2A function during cell elongation and spore germination.
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Affiliation(s)
- Jordan Delisle
- Laboratoire de Chimie Bactérienne, UMR 7283, CNRS/Aix-Marseille Univ, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Baptiste Cordier
- Laboratoire de Chimie Bactérienne, UMR 7283, CNRS/Aix-Marseille Univ, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Stéphane Audebert
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Matthieu Pophillat
- Aix-Marseille Univ, INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Caroline Cluzel
- Laboratoire de Biologie Tissulaire et Ingénierie Thérapeutique, UMR 5305, CNRS/Université Lyon I, Lyon, France
| | - Leon Espinosa
- Laboratoire de Chimie Bactérienne, UMR 7283, CNRS/Aix-Marseille Univ, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, UMR 5086, CNRS/Université Lyon I, Lyon, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne, UMR 7283, CNRS/Aix-Marseille Univ, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Thierry Doan
- Laboratoire de Chimie Bactérienne, UMR 7283, CNRS/Aix-Marseille Univ, Institut de Microbiologie de la Méditerranée, Marseille, France
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16
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Méheust R, Huang S, Rivera-Lugo R, Banfield JF, Light SH. Post-translational flavinylation is associated with diverse extracytosolic redox functionalities throughout bacterial life. eLife 2021; 10:66878. [PMID: 34032212 PMCID: PMC8238504 DOI: 10.7554/elife.66878] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/24/2021] [Indexed: 12/11/2022] Open
Abstract
Disparate redox activities that take place beyond the bounds of the prokaryotic cell cytosol must connect to membrane or cytosolic electron pools. Proteins post-translationally flavinylated by the enzyme ApbE mediate electron transfer in several characterized extracytosolic redox systems but the breadth of functions of this modification remains unknown. Here, we present a comprehensive bioinformatic analysis of 31,910 prokaryotic genomes that provides evidence of extracytosolic ApbEs within ~50% of bacteria and the involvement of flavinylation in numerous uncharacterized biochemical processes. By mining flavinylation-associated gene clusters, we identify five protein classes responsible for transmembrane electron transfer and two domains of unknown function (DUF2271 and DUF3570) that are flavinylated by ApbE. We observe flavinylation/iron transporter gene colocalization patterns that implicate functions in iron reduction and assimilation. We find associations with characterized and uncharacterized respiratory oxidoreductases that highlight roles of flavinylation in respiratory electron transport chains. Finally, we identify interspecies gene cluster variability consistent with flavinylation/cytochrome functional redundancies and discover a class of ‘multi-flavinylated proteins’ that may resemble multi-heme cytochromes in facilitating longer distance electron transfer. These findings provide mechanistic insight into an important facet of bacterial physiology and establish flavinylation as a functionally diverse mediator of extracytosolic electron transfer. In bacteria, certain chemical reactions required for life do not take place directly inside the cells. For instance, ‘redox’ reactions essential to gather minerals, repair proteins and obtain energy are localised in the membranes and space that surround a bacterium. These chemical reactions involve electrons being transferred from one molecule to another in a cascade that connects the exterior of a cell to its internal space. The enzyme ApbE allows proteins to perform electron transfer by equipping them with ring-like compounds called flavins, through a process known as flavinylation. Yet, the prevelance of flavinylation in bacteria and the scope of redox reactions it facilitates has remained unclear. To investigate this question, Méheust, Huang et al. analysed over 30,000 bacterial genomes, finding genes essential for ApbE flavinylation in about half of all bacterial species across the tree of life. The role of ApbE-flavinylated proteins was then deciphered using a ‘guilt by association’ approach. In bacteria, genes that perform similar roles are often close to each other in the genome, which helps to infer the function of a protein coded by a specific gene. This approach revealed that flavinylation is involved in processes that allow bacteria to acquire iron and to use various energy sources. A number of interesting proteins were also identified, including a group that carry multiple flavins, and could therefore, in theory, transfer electrons over long distances. This discovery could be relevant to bioelectronic applications, which are already considering another class of bacterial electron-carrying molecules as candidates to form minuscule electric wires.
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Affiliation(s)
- Raphaël Méheust
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, United States.,Innovative Genomics Institute, Berkeley, United States.,LABGeM, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, Evry, France
| | - Shuo Huang
- Duchossois Family Institute, University of Chicago, Chicago, United States.,Department of Microbiology, University of Chicago, Chicago, United States
| | - Rafael Rivera-Lugo
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, United States.,Innovative Genomics Institute, Berkeley, United States
| | - Samuel H Light
- Duchossois Family Institute, University of Chicago, Chicago, United States.,Department of Microbiology, University of Chicago, Chicago, United States
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17
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Emanuel E, Dubrovin I, Pogreb R, Pinhasi GA, Cahan R. Resuscitation of Pulsed Electric Field-Treated Staphylococcus aureus and Pseudomonas putida in a Rich Nutrient Medium. Foods 2021; 10:foods10030660. [PMID: 33808827 PMCID: PMC8003612 DOI: 10.3390/foods10030660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 03/04/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
Abstract
Pulsed electric fields (PEFs) technology was reported to be useful as a disinfection method in the liquid food industry. This technology may lead to membrane permeabilization and bacterial death. However, resuscitation of viable but non-culturable cells and sublethally injured microorganisms in food was reported to be associated with foodborne outbreaks. The main aim of this study was to investigate the possible recovery of injured PEF-treated bacteria. The PEF treatment of Staphylococcus aureus and Pseudomonas putida led to a reduction of 3.2 log10 and 4.8 log10, respectively. After 5 h, no colony forming units (CFUs) were observed when the bacteria were suspended in phosphate buffer saline (PBS); and for 24 h, no recovery was observed. The PEF-treated S. aureus in brain-heart infusion (BHI) medium were maintained at 1.84 × 104 CFU mL−1 for about 1.5 h. While P. putida decreased to zero CFU mL−1 by the 4th hour. However, after that, both bacteria recovered and began to multiply. Flow cytometry analysis showed that PEF treatment led to significant membrane permeabilization. Mass spectrometry analysis of PEF-treated P. putida which were suspended in BHI revealed over-expression of 22 proteins, where 55% were related to stress conditions. Understanding the recovery conditions of PEF-treated bacteria is particularly important in food industry pasteurization. To our knowledge, this is the first comprehensive study describing the recovery of injured PEF-treated S. aureus and P. putida bacteria.
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Affiliation(s)
- Efrat Emanuel
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel; (E.E.); (I.D.); (G.A.P.)
| | - Irina Dubrovin
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel; (E.E.); (I.D.); (G.A.P.)
| | - Roman Pogreb
- Department of Physics, Ariel University, Ariel 40700, Israel;
| | - Gad A. Pinhasi
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel; (E.E.); (I.D.); (G.A.P.)
| | - Rivka Cahan
- Department of Chemical Engineering, Ariel University, Ariel 40700, Israel; (E.E.); (I.D.); (G.A.P.)
- Correspondence: ; Tel.: +972-54-7740293
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18
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Scheithauer L, Thiem S, Schmelz S, Dellmann A, Büssow K, Brouwer RMHJ, Ünal CM, Blankenfeldt W, Steinert M. Zinc metalloprotease ProA of Legionella pneumophila increases alveolar septal thickness in human lung tissue explants by collagen IV degradation. Cell Microbiol 2021; 23:e13313. [PMID: 33491325 DOI: 10.1111/cmi.13313] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 01/25/2023]
Abstract
ProA is a secreted zinc metalloprotease of Legionella pneumophila causing lung damage in animal models of Legionnaires' disease. Here we demonstrate that ProA promotes infection of human lung tissue explants (HLTEs) and dissect the contribution to cell type specific replication and extracellular virulence mechanisms. For the first time, we reveal that co-incubation of HLTEs with purified ProA causes a significant increase of the alveolar septal thickness. This destruction of connective tissue fibres was further substantiated by collagen IV degradation assays. The moderate attenuation of a proA-negative mutant in A549 epithelial cells and THP-1 macrophages suggests that effects of ProA in tissue mainly result from extracellular activity. Correspondingly, ProA contributes to dissemination and serum resistance of the pathogen, which further expands the versatile substrate spectrum of this thermolysin-like protease. The crystal structure of ProA at 1.48 Å resolution showed high congruence to pseudolysin of Pseudomonas aeruginosa, but revealed deviations in flexible loops, the substrate binding pocket S1 ' and the repertoire of cofactors, by which ProA can be distinguished from respective homologues. In sum, this work specified virulence features of ProA at different organisational levels by zooming in from histopathological effects in human lung tissue to atomic details of the protease substrate determination.
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Affiliation(s)
- Lina Scheithauer
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefanie Thiem
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefan Schmelz
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Ansgar Dellmann
- Institut für Pathologie, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, Germany
| | - Konrad Büssow
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - René M H J Brouwer
- Herz-, Thorax-, Gefäßchirurgie, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, Germany.,Institut für Psychologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Can M Ünal
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Fen Fakültesi, Turkish-German University, Istanbul, Turkey
| | - Wulf Blankenfeldt
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.,Institut für Biochemie, Biotechnologie und Bioinformatik, Technische Universität Braunschweig, Braunschweig, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
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19
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Hasan R, Rony MNH, Ahmed R. In silico characterization and structural modeling of bacterial metalloprotease of family M4. J Genet Eng Biotechnol 2021; 19:25. [PMID: 33528696 PMCID: PMC7851659 DOI: 10.1186/s43141-020-00105-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 12/15/2020] [Indexed: 01/20/2023]
Abstract
BACKGROUND The M4 family of metalloproteases is comprised of a large number of zinc-containing metalloproteases. A large number of these enzymes are important virulence factors of pathogenic bacteria and therefore potential drug targets. Whereas some enzymes have potential for biotechnological applications, the M4 family of metalloproteases is known almost exclusively from bacteria. The aim of the study was to identify the structure and properties of M4 metalloprotease proteins. RESULTS A total of 31 protein sequences of M4 metalloprotease retrieved from UniProt representing different species of bacteria have been characterized for various physiochemical properties. They were thermostable, hydrophillic protein of a molecular mass ranging from 38 to 66 KDa. Correlation on the basis of both enzymes and respective genes has also been studied by phylogenetic tree. B. cereus M4 metalloprotease (PDB ID: 1NPC) was selected as a representative species for secondary and tertiary structures among the M4 metalloprotease proteins. The secondary structure displaying 11 helices (H1-H11) is involved in 15 helix-helix interactions, while 4 β-sheet motifs composed of 15 β-strands in PDBsum. Possible disulfide bridges were absent in most of the cases. The tertiary structure of B. cereus M4 metalloprotease was validated by QMEAN4 and SAVES server (Ramachandran plot, verify 3D, and ERRAT) which proved the stability, reliability, and consistency of the tertiary structure of the protein. Functional analysis was done in terms of membrane protein topology, disease-causing region prediction, proteolytic cleavage sites prediction, and network generation. Transmembrane helix prediction showed absence of transmembrane helix in protein. Protein-protein interaction networks demonstrated that bacillolysin of B. cereus interacted with ten other proteins in a high confidence score. Five disorder regions were identified. Active sites analysis showed the zinc-binding residues-His-143, His-147, and Glu-167, with Glu-144 acting as the catalytic residues. CONCLUSION Moreover, this theoretical overview will help researchers to get a details idea about the protein structure and it may also help to design enzymes with desirable characteristics for exploiting them at industrial level or potential drug targets.
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Affiliation(s)
- Rajnee Hasan
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207 Bangladesh
| | - Md. Nazmul Haq Rony
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207 Bangladesh
| | - Rasel Ahmed
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207 Bangladesh
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20
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Identification of signaling pathways, matrix-digestion enzymes, and motility components controlling Vibrio cholerae biofilm dispersal. Proc Natl Acad Sci U S A 2020; 117:32639-32647. [PMID: 33288715 PMCID: PMC7768729 DOI: 10.1073/pnas.2021166117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The global pathogen Vibrio cholerae alternates between free swimming and existing in sessile multicellular communities known as biofilms. Transitioning between these lifestyles is key for disease transmission. V. cholerae biofilm formation is well studied; however, almost nothing is known about how V. cholerae cells disperse from biofilms, precluding our understanding of a central pathogenicity step. Here, we conducted an imaging screen for V. cholerae mutants that failed to disperse. Our screen revealed three classes of components required for dispersal: signal transduction, matrix degradation, and motility factors. We characterized these components to reveal the sequence of molecular events that choreograph V. cholerae biofilm dispersal. Our report provides a framework for developing strategies to modulate biofilm dispersal to prevent or treat disease. Bacteria alternate between being free-swimming and existing as members of sessile multicellular communities called biofilms. The biofilm lifecycle occurs in three stages: cell attachment, biofilm maturation, and biofilm dispersal. Vibrio cholerae biofilms are hyperinfectious, and biofilm formation and dispersal are considered central to disease transmission. While biofilm formation is well studied, almost nothing is known about biofilm dispersal. Here, we conducted an imaging screen for V. cholerae mutants that fail to disperse, revealing three classes of dispersal components: signal transduction proteins, matrix-degradation enzymes, and motility factors. Signaling proteins dominated the screen and among them, we focused on an uncharacterized two-component sensory system that we term DbfS/DbfR for dispersal of biofilm sensor/regulator. Phospho-DbfR represses biofilm dispersal. DbfS dephosphorylates and thereby inactivates DbfR, which permits dispersal. Matrix degradation requires two enzymes: LapG, which cleaves adhesins, and RbmB, which digests matrix polysaccharides. Reorientation in swimming direction, mediated by CheY3, is necessary for cells to escape from the porous biofilm matrix. We suggest that these components act sequentially: signaling launches dispersal by terminating matrix production and triggering matrix digestion, and subsequent cell motility permits escape from biofilms. This study lays the groundwork for interventions aimed at modulating V. cholerae biofilm dispersal to ameliorate disease.
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21
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Kopeckova M, Pavkova I, Link M, Rehulka P, Stulik J. Identification of Bacterial Protein Interaction Partners Points to New Intracellular Functions of Francisella tularensis Glyceraldehyde-3-Phosphate Dehydrogenase. Front Microbiol 2020; 11:576618. [PMID: 33013814 PMCID: PMC7513575 DOI: 10.3389/fmicb.2020.576618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/19/2020] [Indexed: 11/13/2022] Open
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is well known for its involvement in numerous non-metabolic processes inside mammalian cells. Alternative functions of prokaryotic GAPDH are mainly deduced from its extracellular localization ability to bind to selected host proteins. Data on its participation in intracellular bacterial processes are scarce as there has been to date only one study dealing with this issue. We previously have reported several points of evidence that the GAPDH homolog of Francisella tularensis GapA might also exert additional non-enzymatic functions. Following on from our earlier observations we decided to identify GapA's interacting partners within the bacterial proteome to explore its new roles at intracellular level. The quantitative proteomics approach based on stable isotope labeling of amino acids in cell culture (SILAC) in combination with affinity purification mass spectrometry enabled us to identify 18 proteins potentially interacting with GapA. Six of those interactions were further confirmed by alternative methods. Half of the identified proteins were involved in non-metabolic processes. Further analysis together with quantitative label-free comparative analysis of proteomes isolated from the wild-type strain strain with deleted gapA gene suggests that GapA is implicated in DNA repair processes. Absence of GapA promotes secretion of its most potent interaction partner the hypothetical protein with peptidase propeptide domain (PepSY) thereby indicating that it impacts on subcellular distribution of some proteins.
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Affiliation(s)
- Monika Kopeckova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
| | - Ivona Pavkova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
| | - Marek Link
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
| | - Pavel Rehulka
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
| | - Jiri Stulik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
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22
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Galdino ACM, de Oliveira MP, Ramalho TC, de Castro AA, Branquinha MH, Santos ALS. Anti-Virulence Strategy against the Multidrug-Resistant Bacterial Pathogen Pseudomonas aeruginosa: Pseudolysin (Elastase B) as a Potential Druggable Target. Curr Protein Pept Sci 2019; 20:471-487. [PMID: 30727891 DOI: 10.2174/1389203720666190207100415] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/26/2019] [Accepted: 01/31/2019] [Indexed: 11/22/2022]
Abstract
Pseudomonas aeruginosa is a non-fermentative, gram-negative bacterium that is one of the most common pathogens responsible for hospital-acquired infections worldwide. The management of the infections caused by P. aeruginosa represents a huge challenge in the healthcare settings due to the increased emergence of resistant isolates, some of them resistant to all the currently available antimicrobials, which results in elevated morbimortality rates. Consequently, the development of new therapeutic strategies against multidrug-resistant P. aeruginosa is urgent and needful. P. aeruginosa is wellrecognized for its extreme genetic versatility and its ability to produce a lush variety of virulence factors. In this context, pseudolysin (or elastase B) outstands as a pivotal virulence attribute during the infectious process, playing multifunctional roles in different aspects of the pathogen-host interaction. This protein is a 33-kDa neutral zinc-dependent metallopeptidase that is the most abundant peptidase found in pseudomonal secretions, which contributes to the invasiveness of P. aeruginosa due to its ability to cleave several extracellular matrix proteins and to disrupt the basolateral intercellular junctions present in the host tissues. Moreover, pseudolysin makes P. aeruginosa able to overcome host defenses by the hydrolysis of many immunologically relevant molecules, including antibodies and complement components. The attenuation of this striking peptidase therefore emerges as an alternative and promising antivirulence strategy to combat antibiotic-refractory infections caused by P. aeruginosa. The anti-virulence approach aims to disarm the P. aeruginosa infective arsenal by inhibiting the expression/activity of bacterial virulence factors in order to reduce the invasiveness of P. aeruginosa, avoiding the emergence of resistance since the proliferation is not affected. This review summarizes the most relevant features of pseudolysin and highlights this enzyme as a promising target for the development of new anti-virulence compounds.
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Affiliation(s)
- Anna Clara M Galdino
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Matheus P de Oliveira
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA, United States
| | - Teodorico C Ramalho
- Departamento de Quimica, Universidade Federal de Lavras, Minas Gerais, Brazil
| | | | - Marta H Branquinha
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - André L S Santos
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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23
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Towards functional characterization of archaeal genomic dark matter. Biochem Soc Trans 2019; 47:389-398. [PMID: 30710061 PMCID: PMC6393860 DOI: 10.1042/bst20180560] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 01/07/2023]
Abstract
A substantial fraction of archaeal genes, from ∼30% to as much as 80%, encode ‘hypothetical' proteins or genomic ‘dark matter'. Archaeal genomes typically contain a higher fraction of dark matter compared with bacterial genomes, primarily, because isolation and cultivation of most archaea in the laboratory, and accordingly, experimental characterization of archaeal genes, are difficult. In the present study, we present quantitative characteristics of the archaeal genomic dark matter and discuss comparative genomic approaches for functional prediction for ‘hypothetical' proteins. We propose a list of top priority candidates for experimental characterization with a broad distribution among archaea and those that are characteristic of poorly studied major archaeal groups such as Thaumarchaea, DPANN (Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota and Nanohaloarchaeota) and Asgard.
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24
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Functional annotation of operome from Methanothermobacter thermautotrophicus ΔH: An insight to metabolic gap filling. Int J Biol Macromol 2018; 123:350-362. [PMID: 30445075 DOI: 10.1016/j.ijbiomac.2018.11.100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/10/2018] [Accepted: 11/12/2018] [Indexed: 12/16/2022]
Abstract
Methanothermobacter thermautotrophicus ΔH (MTH) is a potential methanogen known to reduce CO2 with H2 for producing methane biofuel in thermophilic digesters. The genome of this organism contains ~50.5% conserved hypothetical proteins (HPs; operome) whose function is still not determined precisely. Here, we employed a combined bioinformatics approach to annotate a precise function to HPs and categorize them as enzymes, binding proteins, and transport proteins. Results of our study show that 315 (35.6%) HPs have exhibited well-defined functions contributing imperative roles in diverse cellular metabolism. Some of them are responsible for stress-response mechanisms and cell cycle, membrane transport, and regulatory processes. The genome-neighborhood analysis found five important gene clusters (dsr, ehb, kaiC, cmr, and gas) involving in the energetic metabolism and defense systems. MTH operome contains 223 enzymes with 15 metabolic subsystems, 15 cell cycle proteins, 17 transcriptional regulators and 33 binding proteins. Functional annotation of its operome is thus more fundamental to a profound understanding of the molecular and cellular machinery at systems-level.
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25
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Na Pombejra S, Jamklang M, Uhrig JP, Vu K, Gelli A. The structure-function analysis of the Mpr1 metalloprotease determinants of activity during migration of fungal cells across the blood-brain barrier. PLoS One 2018; 13:e0203020. [PMID: 30161190 PMCID: PMC6117016 DOI: 10.1371/journal.pone.0203020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022] Open
Abstract
Cryptococcal meningoencephalitis, the most common form of cryptococcosis, is caused by the opportunistic fungal pathogen, Cryptococcus neoformans. Molecular strategies used by C. neoformans to invade the central nervous system (CNS) have been the focus of several studies. Recently, the role of a novel secreted metalloprotease (Mpr1) in the pathogenicity of C. neoformans was confirmed by studies demonstrating that Mpr1 mediated the migration of fungal cells into the CNS. Given this central function, the aim here was to identify the molecular determinants of Mpr1 activity and resolve their role in the migration of cryptococci across the blood-brain barrier (BBB). The Mpr1 protein belongs to an understudied group of metalloproteases of the M36 class of fungalysins unique to fungi. They are generally synthesized as propeptides with fairly long prodomains and highly conserved regions within their catalytic core. Through structure-function analysis of Mpr1, our study identified the prodomain cleavage sites of Mpr1 and demonstrated that when mutated, the prodomain appears to remain attached to the catalytic C-terminus of Mpr1 rendering a nonfunctional Mpr1 protein and an inability for cryptococci to cross the BBB. We found that proteolytic activity of Mpr1 was dependent on the coordination of zinc with two histidine residues in the active site of Mpr1, since amino acid substitutions in the HExxH motif abolished Mpr1 proteolytic activity and prevented the migration of cryptococci across the BBB. A phylogenetic analysis of Mpr1 revealed a distinct pattern likely reflecting the neurotropic nature of C. neoformans and the specific function of Mpr1 in breaching the BBB. This study contributes to a deeper understanding of the molecular regulation of Mpr1 activity and may lead to the development of specific inhibitors that could be used to restrict fungal penetration of the CNS and thus prevent cryptococcal meningoencephalitis-related deaths.
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Affiliation(s)
- Sarisa Na Pombejra
- Department of Pharmacology, School of Medicine, University of California, Davis, California, United States of America
| | - Mantana Jamklang
- Department of Pharmacology, School of Medicine, University of California, Davis, California, United States of America
| | - John P. Uhrig
- Department of Pharmacology, School of Medicine, University of California, Davis, California, United States of America
| | - Kiem Vu
- Department of Pharmacology, School of Medicine, University of California, Davis, California, United States of America
| | - Angie Gelli
- Department of Pharmacology, School of Medicine, University of California, Davis, California, United States of America
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26
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Zhao H, Roistacher DM, Helmann JD. Aspartate deficiency limits peptidoglycan synthesis and sensitizes cells to antibiotics targeting cell wall synthesis in Bacillus subtilis. Mol Microbiol 2018; 109:826-844. [PMID: 29995990 DOI: 10.1111/mmi.14078] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/02/2018] [Accepted: 07/05/2018] [Indexed: 12/31/2022]
Abstract
Peptidoglycan synthesis is an important target for antibiotics and relies on intermediates derived from central metabolism. As a result, alterations of metabolism may affect antibiotic sensitivity. An aspB mutant is auxotrophic for aspartate (Asp) and asparagine (Asn) and lyses when grown in Difco sporulation medium (DSM), but not in LB medium. Genetic and physiological studies, supported by amino acid analysis, reveal that cell lysis in DSM results from Asp limitation due to a relatively low Asp and high glutamate (Glu) concentrations, with Glu functioning as a competitive inhibitor of Asp uptake by the major Glu/Asp transporter GltT. Lysis can be specifically suppressed by supplementation with 2,6-diaminopimelate (DAP), which is imported by two different cystine uptake systems. These studies suggest that aspartate limitation depletes the peptidoglycan precursor meso-2,6-diaminopimelate (mDAP), inhibits peptidoglycan synthesis, upregulates the cell envelope stress response mediated by σM and eventually leads to cell lysis. Aspartate limitation sensitizes cells to antibiotics targeting late steps of PG synthesis, but not steps prior to the addition of mDAP into the pentapeptide sidechain. This work highlights the ability of perturbations of central metabolism to sensitize cells to peptidoglycan synthesis inhibitors.
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Affiliation(s)
- Heng Zhao
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, NY, USA
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27
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Graf A, Lewis RJ, Fuchs S, Pagels M, Engelmann S, Riedel K, Pané-Farré J. The hidden lipoproteome of Staphylococcus aureus. Int J Med Microbiol 2018; 308:569-581. [PMID: 29454809 DOI: 10.1016/j.ijmm.2018.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/28/2017] [Accepted: 01/27/2018] [Indexed: 01/11/2023] Open
Abstract
Lipoproteins are attached to the outer leaflet of the membrane by a di- or tri-acylglyceryl moiety and are thus positioned in the membrane-cell wall interface. Consequently, lipoproteins are involved in many surface associated functions, including cell wall synthesis, electron transport, uptake of nutrients, surface stress response, signal transduction, and they represent a reservoir of bacterial virulence factors. Inspection of 123 annotated Staphylococcus aureus genome sequences in the public domain revealed that this organism devotes about 2-3% of its coding capacity to lipoproteins, corresponding to about 70 lipoproteins per genome. 60 of these lipoproteins were identified in 95% of the genomes analyzed, which thus constitute the core lipoproteome of S. aureus. 30% of the conserved staphylococcal lipoproteins are substrate-binding proteins of ABC transporters with roles in nutrient transport. With a few exceptions, much less is known about the function of the remaining lipoproteins, representing a large gap in our knowledge of this functionally important group of proteins. Here, we summarize current knowledge, and integrate information from genetic context analysis, expression and regulatory data, domain architecture, sequence and structural information, and phylogenetic distribution to provide potential starting points for experimental evaluation of the biological function of the poorly or uncharacterized lipoproteome of S. aureus.
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Affiliation(s)
- Anica Graf
- Institute of Microbiology, Department of Microbial Physiology and Molecular Biology, Center for Functional Genomics of Microbes (CFGM), University of Greifswald, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Richard J Lewis
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Stephan Fuchs
- FG13 Nosocomial Pathogens and Antibiotic Resistance, Robert Koch Institut (RKI), Burgstr. 37, 38855 Wernigerode, Germany
| | - Martin Pagels
- Institute of Microbiology, Department of Microbial Physiology and Molecular Biology, Center for Functional Genomics of Microbes (CFGM), University of Greifswald, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Susanne Engelmann
- Helmholtz Center for Infection Research GmbH, Microbial Proteomics, Inhoffenstraße 7, 38124 Braunschweig, Germany; Institute for Microbiology, Department of Microbial Proteomics, Technical University Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany
| | - Katharina Riedel
- Institute of Microbiology, Department of Microbial Physiology and Molecular Biology, Center for Functional Genomics of Microbes (CFGM), University of Greifswald, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Jan Pané-Farré
- Institute of Microbiology, Department of Microbial Physiology and Molecular Biology, Center for Functional Genomics of Microbes (CFGM), University of Greifswald, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany.
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Variable Membrane Protein A of Flavescence Dorée Phytoplasma Binds the Midgut Perimicrovillar Membrane of Euscelidius variegatus and Promotes Adhesion to Its Epithelial Cells. Appl Environ Microbiol 2018; 84:AEM.02487-17. [PMID: 29439985 DOI: 10.1128/aem.02487-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/30/2018] [Indexed: 01/27/2023] Open
Abstract
Phytoplasmas are uncultivated plant pathogens and cell wall-less bacteria and are transmitted from plant to plant by hemipteran insects. The phytoplasma's circulative propagative cycle in insects requires the crossing of the midgut and salivary glands, and primary adhesion to cells is an initial step toward the invasion process. The flavescence dorée (FD) phytoplasma possesses a set of variable membrane proteins (Vmps) exposed on its surface, and this pathogen is suspected to interact with insect cells. The results showed that VmpA is expressed by the flavescence dorée phytoplasma present in the midgut and salivary glands. Phytoplasmas cannot be cultivated at present, and no mutant can be produced to investigate the putative role of Vmps in the adhesion of phytoplasma to insect cells. To overcome this difficulty, we engineered the Spiroplasma citri mutant G/6, which lacks the ScARP adhesins, for VmpA expression and used VmpA-coated fluorescent beads to determine if VmpA acts as an adhesin in ex vivo adhesion assays and in vivo ingestion assays. VmpA specifically interacted with Euscelidius variegatus insect cells in culture and promoted the retention of VmpA-coated beads to the midgut of E. variegatus In this latest case, VmpA-coated fluorescent beads were localized and embedded in the perimicrovillar membrane of the insect midgut. Thus, VmpA functions as an adhesin that could be essential in the colonization of the insect by the FD phytoplasmas.IMPORTANCE Phytoplasmas infect a wide variety of plants, ranging from wild plants to cultivated species, and are transmitted by different leafhoppers, planthoppers, and psyllids. The specificity of the phytoplasma-insect vector interaction has a major impact on the phytoplasma plant host range. As entry into insect cells is an obligate process for phytoplasma transmission, the bacterial adhesion to insect cells is a key step. Thus, studying surface-exposed proteins of phytoplasma will help to identify the adhesins implicated in the specific recognition of insect vectors. In this study, it is shown that the membrane protein VmpA of the flavescence dorée (FD) phytoplasma acts as an adhesin that is able to interact with cells of Euscelidius variegatus, the experimental vector of the FD phytoplasma.
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Bradshaw WJ, Roberts AK, Shone CC, Acharya KR. The structure of the S-layer of Clostridium difficile. J Cell Commun Signal 2018; 12:319-331. [PMID: 29170885 PMCID: PMC5842191 DOI: 10.1007/s12079-017-0429-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 10/25/2017] [Indexed: 12/28/2022] Open
Abstract
The nosocomially acquired pathogen Clostridium difficile is the primary causative agent of antibiotic associated diarrhoea and causes tens of thousands of deaths globally each year. C. difficile presents a paracrystalline protein array on the surface of the cell known as an S-layer. S-layers have been demonstrated to possess a wide range of important functions, which, combined with their inherent accessibility, makes them a promising drug target. The unusually complex S-layer of C. difficile is primarily comprised of the high- and low- molecular weight S-layer proteins, HMW SLP and LMW SLP, formed from the cleavage of the S-layer precursor protein, SlpA, but may also contain up to 28 SlpA paralogues. A model of how the S-layer functions as a whole is required if it is to be exploited in fighting the bacterium. Here, we provide a summary of what is known about the S-layer of C. difficile and each of the paralogues and, considering some of the domains present, suggest potential roles for them.
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Affiliation(s)
- William J Bradshaw
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
- Public Health England, Porton Down, Salisbury, SP4 0JG, UK
| | | | | | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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Abstract
Bacterial endospores possess multiple integument layers, one of which is the cortex peptidoglycan wall. The cortex is essential for the maintenance of spore core dehydration and dormancy and contains structural modifications that differentiate it from vegetative cell peptidoglycan and determine its fate during spore germination. Following the engulfment stage of sporulation, the cortex is synthesized within the intermembrane space surrounding the forespore. Proteins responsible for cortex synthesis are produced in both the forespore and mother cell compartments. While some of these proteins also contribute to vegetative cell wall synthesis, others are sporulation specific. In order for the bacterial endospore to germinate and resume metabolism, the cortex peptidoglycan must first be degraded through the action of germination-specific lytic enzymes. These enzymes are present, yet inactive, in the dormant spore and recognize the muramic-δ-lactam modification present in the cortex. Germination-specific lytic enzymes across Bacillaceae and Clostridiaceae share this specificity determinant, which ensures that the spore cortex is hydrolyzed while the vegetative cell wall remains unharmed. Bacillus species tend to possess two redundant enzymes, SleB and CwlJ, capable of sufficient cortex degradation, while the clostridia have only one, SleC. Additional enzymes are often present that cannot initiate the cortex degradation process, but which can increase the rate of release of small fragments into the medium. Between the two families, the enzymes also differ in the enzymatic activities they possess and the mechanisms acting to restrict their activation until germination has been initiated.
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31
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Quintana J, Novoa-Aponte L, Argüello JM. Copper homeostasis networks in the bacterium Pseudomonas aeruginosa. J Biol Chem 2017; 292:15691-15704. [PMID: 28760827 DOI: 10.1074/jbc.m117.804492] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/21/2017] [Indexed: 11/06/2022] Open
Abstract
Bacterial copper (Cu+) homeostasis enables both precise metallation of diverse cuproproteins and control of variable metal levels. To this end, protein networks mobilize Cu+ to cellular targets with remarkable specificity. However, the understanding of these processes is rather fragmented. Here, we use genome-wide transcriptomic analysis by RNA-Seq to characterize the response of Pseudomonas aeruginosa to external 0.5 mm CuSO4, a condition that did not generate pleiotropic effects. Pre-steady-state (5-min) and steady-state (2-h) Cu+ fluxes resulted in distinct transcriptome landscapes. Cells quickly responded to Cu2+ stress by slowing down metabolism. This was restored once steady state was reached. Specific Cu+ homeostasis genes were strongly regulated in both conditions. Our system-wide analysis revealed induction of three Cu+ efflux systems (a P1B-ATPase, a porin, and a resistance-nodulation-division (RND) system) and of a putative Cu+-binding periplasmic chaperone and the unusual presence of two cytoplasmic CopZ proteins. Both CopZ chaperones could bind Cu+ with high affinity. Importantly, novel transmembrane transporters probably mediating Cu+ influx were among those largely repressed upon Cu+ stress. Compartmental Cu+ levels appear independently controlled; the cytoplasmic Cu+ sensor CueR controls cytoplasmic chaperones and plasma membrane transporters, whereas CopR/S responds to periplasmic Cu+ Analysis of ΔcopR and ΔcueR mutant strains revealed a CopR regulon composed of genes involved in periplasmic Cu+ homeostasis and its putative DNA recognition sequence. In conclusion, our study establishes a system-wide model of a network of sensors/regulators, soluble chaperones, and influx/efflux transporters that control the Cu+ levels in P. aeruginosa compartments.
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Affiliation(s)
- Julia Quintana
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - Lorena Novoa-Aponte
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
| | - José M Argüello
- From the Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609
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Patel S, Rauf A, Meher BR. In silico analysis of ChtBD3 domain to find its role in bacterial pathogenesis and beyond. Microb Pathog 2017; 110:519-526. [PMID: 28760454 DOI: 10.1016/j.micpath.2017.07.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 07/24/2017] [Accepted: 07/27/2017] [Indexed: 12/12/2022]
Abstract
Chitin binding domain 3, known by the acronym ChtBD3, is a domain in the enzymes and proteins of several pathogenic virus, bacteria and fungi. As this domain is evolutionarily-conserved in virulence factors of these infectious agents, its detailed investigation is of clinical interest. In this regard, the current in silico study analyzed ChtBD3 domain distribution in bacterial proteins present in publicly-available SMART (simple modular architecture research tool) database. Also, the co-occurring domains of ChtBD3 in the studied proteins were mapped to understand positional rearrangement of the domain and consequent functional diversity. Custom-made scripts were used to interpret the data and to derive patterns. As expected, interesting results were obtained. ChtBD3 domain co-occurred with other critical domains like peptidase, glycol_hydrolase, kinase, hemagglutinin-acting, collagen-binding, among others. The findings are expected to be of clinical relevance.
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Affiliation(s)
- Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego, 92182, USA.
| | - Abdur Rauf
- Department of Chemistry, University of Swabi, Anbar, 23561, Khyber Pakhtunkhwa, Pakistan.
| | - Biswa Ranjan Meher
- Centre for Life Sciences, Central University of Jharkhand, Brambe, Ranchi, 835205, Jharkhand, India
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Poppleton DI, Duchateau M, Hourdel V, Matondo M, Flechsler J, Klingl A, Beloin C, Gribaldo S. Outer Membrane Proteome of Veillonella parvula: A Diderm Firmicute of the Human Microbiome. Front Microbiol 2017; 8:1215. [PMID: 28713344 PMCID: PMC5491611 DOI: 10.3389/fmicb.2017.01215] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/14/2017] [Indexed: 12/24/2022] Open
Abstract
Veillonella parvula is a biofilm-forming commensal found in the lungs, vagina, mouth, and gastro-intestinal tract of humans, yet it may develop into an opportunistic pathogen. Furthermore, the presence of Veillonella has been associated with the development of a healthy immune system in infants. Veillonella belongs to the Negativicutes, a diverse clade of bacteria that represent an evolutionary enigma: they phylogenetically belong to Gram-positive (monoderm) Firmicutes yet maintain an outer membrane (OM) with lipopolysaccharide similar to classic Gram-negative (diderm) bacteria. The OMs of Negativicutes have unique characteristics including the replacement of Braun's lipoprotein by OmpM for tethering the OM to the peptidoglycan. Through phylogenomic analysis, we have recently provided bioinformatic annotation of the Negativicutes diderm cell envelope. We showed that it is a unique type of envelope that was present in the ancestor of present-day Firmicutes and lost multiple times independently in this phylum, giving rise to the monoderm architecture; however, little experimental data is presently available for any Negativicutes cell envelope. Here, we performed the first experimental proteomic characterization of the cell envelope of a diderm Firmicute, producing an OM proteome of V. parvula. We initially conducted a thorough bioinformatics analysis of all 1,844 predicted proteins from V. parvula DSM 2008's genome using 12 different localization prediction programs. These results were complemented by protein extraction with surface exposed (SE) protein tags and by subcellular fractionation, both of which were analyzed by liquid chromatography tandem mass spectrometry. The merging of proteomics and bioinformatics results allowed identification of 78 OM proteins. These include a number of receptors for TonB-dependent transport, the main component of the BAM system for OM protein biogenesis (BamA), the Lpt system component LptD, which is responsible for insertion of LPS into the OM, and several copies of the major OmpM protein. The annotation of V. parvula's OM proteome markedly extends previous inferences on the nature of the cell envelope of Negativicutes, including the experimental evidence of a BAM/TAM system for OM protein biogenesis and of a complete Lpt system for LPS transport to the OM. It also provides important information on the role of OM components in the lifestyle of Veillonella, such as a possible gene cluster for O-antigen synthesis and a large number of adhesins. Finally, many OM hypothetical proteins were identified, which are priority targets for further characterization.
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Affiliation(s)
- Daniel I. Poppleton
- Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut PasteurParis, France
| | - Magalie Duchateau
- Unité de Spectrométrie de Masse Structurale et Protéomique, Plateforme Protéomique, Départment de Biologie Structurale et Chime, Institut Pasteur, USR 2000 Centre National de la Recherche ScientifiqueParis, France
| | - Véronique Hourdel
- Unité de Spectrométrie de Masse Structurale et Protéomique, Plateforme Protéomique, Départment de Biologie Structurale et Chime, Institut Pasteur, USR 2000 Centre National de la Recherche ScientifiqueParis, France
| | - Mariette Matondo
- Unité de Spectrométrie de Masse Structurale et Protéomique, Plateforme Protéomique, Départment de Biologie Structurale et Chime, Institut Pasteur, USR 2000 Centre National de la Recherche ScientifiqueParis, France
| | - Jennifer Flechsler
- Pflanzliche Entwicklungsbiologie und Elektronenmikroskopie, Department I. Botanik, Biozentrum der LMU MünchenPlanegg-Martinsried, Germany
| | - Andreas Klingl
- Pflanzliche Entwicklungsbiologie und Elektronenmikroskopie, Department I. Botanik, Biozentrum der LMU MünchenPlanegg-Martinsried, Germany
| | - Christophe Beloin
- Unité de Génétique des Biofilms, Département de Microbiologie, Institut PasteurParis, France
| | - Simonetta Gribaldo
- Unité de Biologie Moléculaire du Gène chez les Extrêmophiles, Département de Microbiologie, Institut PasteurParis, France
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Vibrio cholerae VciB Mediates Iron Reduction. J Bacteriol 2017; 199:JB.00874-16. [PMID: 28348025 DOI: 10.1128/jb.00874-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 03/19/2017] [Indexed: 11/20/2022] Open
Abstract
Vibrio cholerae is the causative agent of the severe diarrheal disease cholera. V. cholerae thrives within the human host, where it replicates to high numbers, but it also persists within the aquatic environments of ocean and brackish water. To survive within these nutritionally diverse environments, V. cholerae must encode the necessary tools to acquire the essential nutrient iron in all forms it may encounter. A prior study of systems involved in iron transport in V. cholerae revealed the existence of vciB, which, while unable to directly transport iron, stimulates the transport of iron through ferrous (Fe2+) iron transport systems. We demonstrate here a role for VciB in V. cholerae in which VciB stimulates the reduction of Fe3+ to Fe2+, which can be subsequently transported into the cell with the ferrous iron transporter Feo. Iron reduction is independent of functional iron transport but is associated with the electron transport chain. Comparative analysis of VciB orthologs suggests a similar role for other proteins in the VciB family. Our data indicate that VciB is a dimer located in the inner membrane with three transmembrane segments and a large periplasmic loop. Directed mutagenesis of the protein reveals two highly conserved histidine residues required for function. Taken together, our results support a model whereby VciB reduces ferric iron using energy from the electron transport chain.IMPORTANCEVibrio cholerae is a prolific human pathogen and environmental organism. The acquisition of essential nutrients such as iron is critical for replication, and V. cholerae encodes a number of mechanisms to use iron from diverse environments. Here, we describe the V. cholerae protein VciB that increases the reduction of oxidized ferric iron (Fe3+) to the ferrous form (Fe2+), thus promoting iron acquisition through ferrous iron transporters. Analysis of VciB orthologs in Burkholderia and Aeromonas spp. suggest that they have a similar activity, allowing a functional assignment for this previously uncharacterized protein family. This study builds upon our understanding of proteins known to mediate iron reduction in bacteria.
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Liu R, Qiu L, Cheng Q, Zhang H, Wang L, Song L. Evidence for Cleavage of the Metalloprotease Vsm from Vibrio splendidus Strain JZ6 by an M20 Peptidase (PepT-like Protein) at Low Temperature. Front Microbiol 2016; 7:1684. [PMID: 27826294 PMCID: PMC5078317 DOI: 10.3389/fmicb.2016.01684] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/07/2016] [Indexed: 11/13/2022] Open
Abstract
Metalloprotease Vsm is a major extracellular virulence factor of Vibrio splendidus. The toxicity of Vsm from V. splendidus strain JZ6 has been characterized, and production of this virulence factor proved to be temperature-regulated. The present study provides evidence that two forms (JZE1 and JZE2) of Vsm protein exist in extracellular products (ECPs) of strain JZ6, and a significant conversion of these two forms was detected by SDS-PAGE and immunoblotting analyses of samples obtained from cells grown at 4, 10, 16, 20, 24, and 28°C. Mass spectroscopy confirmed that JZE1 was composed only of the peptidase_M4 domain of Vsm, and JZE2 contained both the PepSY domain and the peptidase_M4 domain. An M20 peptidase T-like protein (PepTL) was screened from the transcriptome data of strain JZ6, which was considered as a crucial molecule to produce the active Vsm (JZE1) by cleavage of the propeptide. Similar to that of Vsm, PepTL mRNA accumulation was highest at 4°C (836.82-fold of that at 28°C), decreased with increasing of temperature and reached its lowest level at 28°C. Deletion of the gene encoding the PepTL resulted in a mutant strain that did not produce the JZE1 cleavage product. The peptidase activity of PepTL recombinant protein (rPepTL) was confirmed by cleaving the Vsm in ECPs with an in vitro degradation reaction. These results demonstrate that PepTL participates in activating Vsm in strain JZ6 by proteolytic cleavage at low temperature.
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Affiliation(s)
- Rui Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences Qingdao, China
| | - Limei Qiu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences Qingdao, China
| | - Qi Cheng
- School of Food Science and Technology, Dalian Polytechnic University Dalian, China
| | - Huan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences Qingdao, China
| | - Lingling Wang
- Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University Dalian, China
| | - Linsheng Song
- Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University Dalian, China
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Üstok FI, Chirgadze DY, Christie G. Crystal structure of the PepSY-containing domain of the YpeB protein involved in germination of bacillus
spores. Proteins 2015. [DOI: 10.1002/prot.24868] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fatma Işık Üstok
- Department of Chemical Engineering and Biotechnology; Institute of Biotechnology, University of Cambridge; Cambridge United Kingdom
| | | | - Graham Christie
- Department of Chemical Engineering and Biotechnology; Institute of Biotechnology, University of Cambridge; Cambridge United Kingdom
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Colonization of epidermal tissue by Staphylococcus aureus produces localized hypoxia and stimulates secretion of antioxidant and caspase-14 proteins. Infect Immun 2015; 83:3026-34. [PMID: 25987705 DOI: 10.1128/iai.00175-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/07/2015] [Indexed: 11/20/2022] Open
Abstract
A partial-thickness epidermal explant model was colonized with green fluorescent protein (GFP)-expressing Staphylococcus aureus, and the pattern of S. aureus biofilm growth was characterized using electron and confocal laser scanning microscopy. The oxygen concentration in explants was quantified using microelectrodes. The relative effective diffusivity and porosity of the epidermis were determined using magnetic resonance imaging, while hydrogen peroxide (H2O2) concentration in explant media was measured by using microelectrodes. Secreted proteins were identified and quantified using elevated-energy mass spectrometry (MS(E)). S. aureus biofilm grows predominantly in lipid-rich areas around hair follicles and associated skin folds. Dissolved oxygen was selectively depleted (2- to 3-fold) in these locations, but the relative effective diffusivity and porosity did not change between colonized and control epidermis. Histological analysis revealed keratinocyte damage across all the layers of colonized epidermis after 4 days of culture. The colonized explants released significantly (P < 0.01) more antioxidant proteins of both epidermal and S. aureus origin, consistent with elevated H2O2 concentrations found in the media from the colonized explants (P< 0.001). Caspase-14 was also elevated significantly in the media from the colonized explants. While H2O2 induces primary keratinocyte differentiation, caspase-14 is required for terminal keratinocyte differentiation and desquamation. These results are consistent with a localized biological impact from S. aureus in response to colonization of the skin surface.
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Gamba P, Rietkötter E, Daniel RA, Hamoen LW. Tetracycline hypersensitivity of an ezrA mutant links GalE and TseB (YpmB) to cell division. Front Microbiol 2015; 6:346. [PMID: 25954268 PMCID: PMC4406074 DOI: 10.3389/fmicb.2015.00346] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 04/08/2015] [Indexed: 11/13/2022] Open
Abstract
Cell division in bacteria is initiated by the polymerization of FtsZ into a ring-like structure at midcell that functions as a scaffold for the other cell division proteins. In Bacillus subtilis, the conserved cell division protein EzrA is involved in modulation of Z-ring formation and coordination of septal peptidoglycan synthesis. Here, we show that an ezrA mutant is hypersensitive to tetracycline, even when the tetracycline efflux pump TetA is present. This effect is not related to the protein translation inhibiting activity of tetracycline. Overexpression of FtsL suppresses this phenotype, which appears to be related to the intrinsic low FtsL levels in an ezrA mutant background. A transposon screen indicated that the tetracycline effect can also be suppressed by overproduction of the cell division protein ZapA. In addition, tetracycline sensitivity could be suppressed by transposon insertions in galE and the unknown gene ypmB, which was renamed tseB (tetracycline sensitivity suppressor of ezrA). GalE is an epimerase using UDP-glucose and UDP-N-acetylglucosamine as substrate. Deletion of this protein bypasses the synthetic lethality of zapA ezrA and sepF ezrA double mutations, indicating that GalE influences cell division. The transmembrane protein TseB contains an extracytoplasmic peptidase domain, and a GFP fusion shows that the protein is enriched at cell division sites. A tseB deletion causes a shorter cell phenotype, indicating that TseB plays a role in cell division. Why a deletion of ezrA renders B. subtilis cells hypersensitive for tetracycline remains unclear. We speculate that this phenomenon is related to the tendency of tetracycline analogs to accumulate into the lipid bilayer, which may destabilize certain membrane proteins.
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Affiliation(s)
- Pamela Gamba
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Eva Rietkötter
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Richard A Daniel
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK
| | - Leendert W Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University Newcastle upon Tyne, UK ; Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
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Arntzen MØ, Karlskås IL, Skaugen M, Eijsink VGH, Mathiesen G. Proteomic Investigation of the Response of Enterococcus faecalis V583 when Cultivated in Urine. PLoS One 2015; 10:e0126694. [PMID: 25915650 PMCID: PMC4411035 DOI: 10.1371/journal.pone.0126694] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/07/2015] [Indexed: 11/19/2022] Open
Abstract
Enterococcus faecalis is a robust bacterium, which is able to survive in and adapt to hostile environments such as the urinary tract and bladder. In this label-free quantitative proteomic study based on MaxQuant LFQ algorithms, we identified 127 proteins present in the secretome of the clinical vancomycin-resistant isolate E. faecalis V583 and we compared proteins secreted in the initial phase of cultivation in urine with the secretome during cultivation in standard laboratory medium, 2xYT. Of the 54 identified proteins predicted to be secreted, six were exclusively found after cultivation in urine including the virulence factor EfaA ("endocarditis specific antigen") and its homologue EF0577 ("adhesion lipoprotein"). These two proteins are both involved in manganese transport, known to be an important determinant of colonization and infection, and may additionally function as adhesins. Other detected urine-specific proteins are involved in peptide transport (EF0063 and EF3106) and protease inhibition (EF3054). In addition, we found an uncharacterized protein (EF0764), which had not previously been linked to the adaptation of V583 to a urine environment, and which is unique to E. faecalis. Proteins found in both environments included a histone-like protein, EF1550, that was up-regulated during cultivation in urine and that has a homologue in streptococci (HlpA) known to be involved in bacterial adhesion to host cells. Up-regulated secreted proteins included autolysins. These results from secretome analyses are largely compatible with previously published data from transcriptomics studies. All in all, the present data indicate that transport, in particular metal transport, adhesion, cell wall remodelling and the unknown function carried out by the unique EF0764 are important for enterococcal adaptation to the urine environment. These results provide a basis for a more targeted exploration of novel proteins involved in the adaptability and pathogenicity of E. faecalis.
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Affiliation(s)
- Magnus Øverlie Arntzen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
- * E-mail:
| | - Ingrid Lea Karlskås
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Morten Skaugen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Vincent G. H. Eijsink
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Geir Mathiesen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
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Role of YpeB in cortex hydrolysis during germination of Bacillus anthracis spores. J Bacteriol 2014; 196:3399-409. [PMID: 25022853 DOI: 10.1128/jb.01899-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The infectious agent of the disease anthrax is the spore of Bacillus anthracis. Bacterial spores are extremely resistant to environmental stresses, which greatly hinders spore decontamination efforts. The spore cortex, a thick layer of modified peptidoglycan, contributes to spore dormancy and resistance by maintaining the low water content of the spore core. The cortex is degraded by germination-specific lytic enzymes (GSLEs) during spore germination, rendering the cells vulnerable to common disinfection techniques. This study investigates the relationship between SleB, a GSLE in B. anthracis, and YpeB, a protein necessary for SleB stability and function. The results indicate that ΔsleB and ΔypeB spores exhibit similar germination phenotypes and that the two proteins have a strict codependency for their incorporation into the dormant spore. In the absence of its partner protein, SleB or YpeB is proteolytically degraded soon after expression during sporulation, rather than escaping the developing spore. The three PepSY domains of YpeB were examined for their roles in the interaction with SleB. YpeB truncation mutants illustrate the necessity of a region beyond the first PepSY domain for SleB stability. Furthermore, site-directed mutagenesis of highly conserved residues within the PepSY domains resulted in germination defects corresponding to reduced levels of both SleB and YpeB in the mutant spores. These results identify residues involved in the stability of both proteins and reiterate their codependent relationship. It is hoped that the study of GSLEs and interacting proteins will lead to the use of GSLEs as targets for efficient activation of spore germination and facilitation of spore cleanup.
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Tzanis A, Dalton KA, Hesketh A, den Hengst CD, Buttner MJ, Thibessard A, Kelemen GH. A sporulation-specific, sigF-dependent protein, SspA, affects septum positioning in Streptomyces coelicolor. Mol Microbiol 2013; 91:363-80. [PMID: 24261854 PMCID: PMC4282423 DOI: 10.1111/mmi.12466] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2013] [Indexed: 01/17/2023]
Abstract
The RNA polymerase sigma factor SigF controls late development during sporulation in the filamentous bacterium Streptomyces coelicolor. The only known SigF-dependent gene identified so far, SCO5321, is found in the biosynthetic cluster encoding spore pigment synthesis. Here we identify the first direct target for SigF, the gene sspA, encoding a sporulation-specific protein. Bioinformatic analysis suggests that SspA is a secreted lipoprotein with two PepSY signature domains. The sspA deletion mutant exhibits irregular sporulation septation and altered spore shape, suggesting that SspA plays a role in septum formation and spore maturation. The fluorescent translational fusion protein SspA–mCherry localized first to septum sites, then subsequently around the surface of the spores. Both SspA protein and sspA transcription are absent from the sigF null mutant. Moreover, in vitro transcription assay confirmed that RNA polymerase holoenzyme containing SigF is sufficient for initiation of transcription from a single sspA promoter. In addition, in vivo and in vitro experiments showed that sspA is a direct target of BldD, which functions to repress sporulation genes, including whiG, ftsZ and ssgB, during vegetative growth, co-ordinating their expression during sporulation septation.
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Affiliation(s)
- Angelos Tzanis
- University of East Anglia, Norwich Research Park, Norwich, UK
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García-Contreras R, Lira-Silva E, Jasso-Chávez R, Hernández-González IL, Maeda T, Hashimoto T, Boogerd FC, Sheng L, Wood TK, Moreno-Sánchez R. Isolation and characterization of gallium resistant Pseudomonas aeruginosa mutants. Int J Med Microbiol 2013; 303:574-82. [DOI: 10.1016/j.ijmm.2013.07.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/09/2013] [Accepted: 07/29/2013] [Indexed: 11/15/2022] Open
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García-Contreras R, Pérez-Eretza B, Lira-Silva E, Jasso-Chávez R, Coria-Jiménez R, Rangel-Vega A, Maeda T, Wood TK. Gallium induces the production of virulence factors inPseudomonas aeruginosa. Pathog Dis 2013; 70:95-8. [DOI: 10.1111/2049-632x.12105] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 09/25/2013] [Accepted: 10/02/2013] [Indexed: 11/29/2022] Open
Affiliation(s)
| | | | | | | | - Rafael Coria-Jiménez
- Laboratory of Experimental Bacteriology; National Institute of Pediatrics; Mexico City Mexico
| | - Adrián Rangel-Vega
- Internal Medicine Department, Speciality Hospital; National Medical Center “Siglo XXI”; IMSS; Mexico City Mexico
| | - Toshinari Maeda
- Department of Biological Functions and Engineering; Kyushu Institute of Technology; Kitakyushu Japan
| | - Thomas K. Wood
- Departments of Chemical Engineering and Biochemistry and Molecular Biology; Pennsylvania State University; University Park PA USA
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Fernández D, Russi S, Vendrell J, Monod M, Pallarès I. A functional and structural study of the major metalloprotease secreted by the pathogenic fungusAspergillus fumigatus. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:1946-57. [DOI: 10.1107/s0907444913017642] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 06/26/2013] [Indexed: 01/09/2023]
Abstract
Fungalysins are secreted fungal peptidases with the ability to degrade the extracellular matrix proteins elastin and collagen and are thought to act as virulence factors in diseases caused by fungi. Fungalysins constitute a unique family among zinc-dependent peptidases that bears low sequence similarity to known bacterial peptidases of the thermolysin family. The crystal structure of the archetype of the fungalysin family,Aspergillus fumigatusmetalloprotease (AfuMep), has been obtained for the first time. The 1.8 Å resolution structure of AfuMep corresponds to that of an autoproteolyzed proenzyme with separate polypeptide chains corresponding to the N-terminal prodomain in a binary complex with the C-terminal zinc-bound catalytic domain. The prodomain consists of a tandem of cystatin-like folds whose C-terminal end is buried into the active-site cleft of the catalytic domain. The catalytic domain harbouring the key catalytic zinc ion and its ligands, two histidines and one glutamic acid, undergoes a conspicuous rearrangement of its N-terminal end during maturation. One key positively charged amino-acid residue and the C-terminal disulfide bridge appear to contribute to its structural–functional properties. Thus, structural, biophysical and biochemical analysis were combined to provide a deeper comprehension of the underlying properties ofA. fumigatusfungalysin, serving as a framework for the as yet poorly known metallopeptidases from pathogenic fungi.
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Papasergi S, Galbo R, Lanza-Cariccio V, Domina M, Signorino G, Biondo C, Pernice I, Poyart C, Trieu-Cuot P, Teti G, Beninati C. Analysis of the Streptococcus agalactiae exoproteome. J Proteomics 2013; 89:154-64. [PMID: 23770297 DOI: 10.1016/j.jprot.2013.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 05/13/2013] [Accepted: 06/02/2013] [Indexed: 10/26/2022]
Abstract
UNLABELLED The two-component regulatory system CovRS is the main regulator of virulence gene expression in Group B Streptococcus (GBS), the leading cause of invasive infections in neonates. In this study we analyzed by mass spectrometry the GBS extracellular protein complex (i.e. the exoproteome) of NEM316 wild-type (WT) strain and its isogenic covRS deletion mutant (ΔcovRS). A total of 53 proteins, 49 of which had classical secretion signals, were identified: 12 were released by both strains while 21 and 20 were released exclusively by WT and ΔcovRS strains, respectively. In addition to known surface proteins, we detected here unstudied cell-wall associated proteins and/or orthologs of putative virulence factors present in other pathogenic streptococci. While the functional role of these proteins remains to be elucidated, our data suggest that the analysis of the exoproteome of bacterial pathogens under different gene expression conditions may be a powerful tool for the rapid identification of novel virulence factors and vaccine candidates. BIOLOGICAL SIGNIFICANCE We believe that this manuscript will be of interest to Journal of Proteomics readers since the paper describes the identification of several putative virulence factors and vaccine candidates of the group B streptococcus, an important pathogen, using a simple proteomics strategy involving LC-MS analysis of culture supernatants obtained from two strains with divergent gene expression patterns. This technique provided the most comprehensive inventory of extracellular proteins obtained from a single streptococcal species thus far. The approach described has the added benefit of being easily applicable to a large number of different strains, making it ideal for the identification of conserved vaccine candidates.
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Activity and regulation of various forms of CwlJ, SleB, and YpeB proteins in degrading cortex peptidoglycan of spores of Bacillus species in vitro and during spore germination. J Bacteriol 2013; 195:2530-40. [PMID: 23543708 DOI: 10.1128/jb.00259-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Germination of Bacillus spores requires degradation of a modified layer of peptidoglycan (PG) termed the spore cortex by two redundant cortex-lytic enzymes (CLEs), CwlJ and SleB, plus SleB's partner protein, YpeB. In this study, in vitro and in vivo analyses have been used to clarify the roles of individual SleB and YpeB domains in PG degradation. Purified mature Bacillus cereus SleB without its signal sequence (SleB(M)) and the SleB C-terminal catalytic domain (SleB(C)) efficiently triggered germination of decoated Bacillus megaterium and Bacillus subtilis spores lacking endogenous CLEs; previously, SleB's N-terminal domain (SleB(N)) was shown to bind PG but have no enzymatic activity. YpeB lacking its putative membrane anchoring sequence (YpeB(M)) or its N- and C-terminal domains (YpeB(N) and YpeB(C)) alone did not exhibit degradative activity, but YpeB(N) inhibited SleB(M) and SleB(C) activity in vitro. The severe germination defect of B. subtilis cwlJ sleB or cwlJ sleB ypeB spores was complemented by ectopic expression of full-length sleB [sleB(FL)] and ypeB [ypeB(FL)], but normal levels of SleB(FL) in spores required normal spore levels of YpeB(FL) and vice versa. sleB(FL) or ypeB(FL) alone, sleB(FL) plus ypeB(C) or ypeB(N), and sleB(C) or sleB(N) plus ypeB(FL) did not complement the cortex degradation defect in cwlJ sleB ypeB spores. In addition, ectopic expression of sleB(FL) or cwlJ(FL) with a Glu-to-Gln mutation in a predicted active-site residue failed to restore the germination of cwlJ sleB spores, supporting the role of this invariant glutamate as the key catalytic residue in SleB and CwlJ.
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BqsR/BqsS constitute a two-component system that senses extracellular Fe(II) in Pseudomonas aeruginosa. J Bacteriol 2011; 194:1195-204. [PMID: 22194456 DOI: 10.1128/jb.05634-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous gram-negative bacterium best known as the predominant opportunistic pathogen infecting the lungs of cystic fibrosis patients. In this context, it is thought to form biofilms, within which locally reducing and acidic conditions can develop that favor the stability of ferrous iron [Fe(II)]. Because iron is a signal that stimulates biofilm formation, we performed a microarray study to determine whether P. aeruginosa strain PA14 exhibits a specific transcriptional response to extracellular Fe(II). Among the genes that were most upregulated in response to Fe(II) were those encoding the two-component system BqsR/BqsS, previously identified for its role in P. aeruginosa strain PAO1 biofilm decay (13); here, we demonstrate its role in extracellular Fe(II) sensing. bqsS and bqsR form an operon together with two small upstream genes, bqsP and bqsQ, and one downstream gene, bqsT. BqsR/BqsS sense extracellular Fe(II) at physiologically relevant concentrations (>10 μM) and elicit a specific transcriptional response, including its autoregulation. The sensor distinguishes between Fe(II), Fe(III), and other dipositive cations [Ca(II), Cu(II), Mg(II), Mn(II), Zn(II)] under aerobic or anaerobic conditions. The gene that is most upregulated by BqsR/BqsS, as measured by quantitative reverse transcription-PCR (qRT-PCR), is PA14_04180, which is predicted to encode a periplasmic oligonucleotide/oligosaccharide-binding domain (OB-fold) protein. Coincident with phenazine production during batch culture growth, Fe(II) becomes the majority of the total iron pool and bqsS is upregulated. The existence of a two-component system that senses Fe(II) indicates that extracellular Fe(II) is an important environmental signal for P. aeruginosa.
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Huis in 't Veld RAG, Willemsen AM, van Kampen AHC, Bradley EJ, Baas F, Pannekoek Y, van der Ende A. Deep sequencing whole transcriptome exploration of the σE regulon in Neisseria meningitidis. PLoS One 2011; 6:e29002. [PMID: 22194974 PMCID: PMC3240639 DOI: 10.1371/journal.pone.0029002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 11/18/2011] [Indexed: 01/24/2023] Open
Abstract
Bacteria live in an ever-changing environment and must alter protein expression promptly to adapt to these changes and survive. Specific response genes that are regulated by a subset of alternative σ70-like transcription factors have evolved in order to respond to this changing environment. Recently, we have described the existence of a σE regulon including the anti-σ-factor MseR in the obligate human bacterial pathogen Neisseria meningitidis. To unravel the complete σE regulon in N. meningitidis, we sequenced total RNA transcriptional content of wild type meningococci and compared it with that of mseR mutant cells (ΔmseR) in which σE is highly expressed. Eleven coding genes and one non-coding gene were found to be differentially expressed between H44/76 wildtype and H44/76ΔmseR cells. Five of the 6 genes of the σE operon, msrA/msrB, and the gene encoding a pepSY-associated TM helix family protein showed enhanced transcription, whilst aniA encoding a nitrite reductase and nspA encoding the vaccine candidate Neisserial surface protein A showed decreased transcription. Analysis of differential expression in IGRs showed enhanced transcription of a non-coding RNA molecule, identifying a σE dependent small non-coding RNA. Together this constitutes the first complete exploration of an alternative σ-factor regulon in N. meningitidis. The results direct to a relatively small regulon indicative for a strictly defined response consistent with a relatively stable niche, the human throat, where N. meningitidis resides.
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Das D, Finn RD, Carlton D, Miller MD, Abdubek P, Astakhova T, Axelrod HL, Bakolitsa C, Chen C, Chiu HJ, Chiu M, Clayton T, Deller MC, Duan L, Ellrott K, Ernst D, Farr CL, Feuerhelm J, Grant JC, Grzechnik A, Han GW, Jaroszewski L, Jin KK, Klock HE, Knuth MW, Kozbial P, Krishna SS, Kumar A, Marciano D, McMullan D, Morse AT, Nigoghossian E, Nopakun A, Okach L, Puckett C, Reyes R, Rife CL, Sefcovic N, Tien HJ, Trame CB, van den Bedem H, Weekes D, Wooten T, Xu Q, Hodgson KO, Wooley J, Elsliger MA, Deacon AM, Godzik A, Lesley SA, Wilson IA. The structure of BVU2987 from Bacteroides vulgatus reveals a superfamily of bacterial periplasmic proteins with possible inhibitory function. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:1265-73. [PMID: 20944221 PMCID: PMC2954215 DOI: 10.1107/s1744309109046788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 11/05/2009] [Indexed: 01/25/2023]
Abstract
Proteins that contain the DUF2874 domain constitute a new Pfam family PF11396. Members of this family have predominantly been identified in microbes found in the human gut and oral cavity. The crystal structure of one member of this family, BVU2987 from Bacteroides vulgatus, has been determined, revealing a β-lactamase inhibitor protein-like structure with a tandem repeat of domains. Sequence analysis and structural comparisons reveal that BVU2987 and other DUF2874 proteins are related to β-lactamase inhibitor protein, PepSY and SmpA_OmlA proteins and hence are likely to function as inhibitory proteins.
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Affiliation(s)
- Debanu Das
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Robert D. Finn
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton CB10 1SA, England
| | - Dennis Carlton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Mitchell D. Miller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Polat Abdubek
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Tamara Astakhova
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Herbert L. Axelrod
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Constantina Bakolitsa
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Connie Chen
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Hsiu-Ju Chiu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Michelle Chiu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Thomas Clayton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Marc C. Deller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lian Duan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Kyle Ellrott
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- University of California, San Diego, La Jolla, CA, USA
| | - Dustin Ernst
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Carol L. Farr
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Julie Feuerhelm
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Joanna C. Grant
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Anna Grzechnik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Gye Won Han
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lukasz Jaroszewski
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Kevin K. Jin
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Heath E. Klock
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Mark W. Knuth
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Piotr Kozbial
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - S. Sri Krishna
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Abhinav Kumar
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - David Marciano
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Daniel McMullan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Andrew T. Morse
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Edward Nigoghossian
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Amanda Nopakun
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Linda Okach
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Christina Puckett
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ron Reyes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Christopher L. Rife
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Natasha Sefcovic
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Henry J. Tien
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Christine B. Trame
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Henry van den Bedem
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dana Weekes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Tiffany Wooten
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Qingping Xu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Keith O. Hodgson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - John Wooley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Marc-André Elsliger
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ashley M. Deacon
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Adam Godzik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Scott A. Lesley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ian A. Wilson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
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50
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Structural basis for the autoprocessing of zinc metalloproteases in the thermolysin family. Proc Natl Acad Sci U S A 2010; 107:17569-74. [PMID: 20876133 DOI: 10.1073/pnas.1005681107] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Thermolysin-like proteases (TLPs), a large group of zinc metalloproteases, are synthesized as inactive precursors. TLPs with a long propeptide (∼200 residues) undergo maturation following autoprocessing through an elusive molecular mechanism. We report the first two crystal structures for the autoprocessed complexes of a typical TLP, MCP-02. In the autoprocessed complex, Ala205 shifts upward by 33 Å from the previously covalently linked residue, His204, indicating that, following autocleavage of the peptide bond between His204 and Ala205, a large conformational change from the zymogen to the autoprocessed complex occurs. The eight N-terminal residues (residues Ala205-Gly212) of the catalytic domain form a new β-strand, nestling into two other β-strands. Simultaneously, the apparent T(m) of the autoprocessed complex increases 20 °C compared to that of the zymogen. The stepwise degradation of the propeptide begins with two sequential cuttings at Ser49-Val50 and Gly57-Leu58, which lead to the disassembly of the propeptide and the formation of mature MCP-02. Our findings give new insights into the molecular mechanism of TLP maturation.
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