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Qi Z, Lei B, Xiong M, Li W, Liao Y, Cai D, Ma X, Zhang R, Chen S. High-level production of chitinase by multi-strategy combination optimization in Bacillus licheniformis. World J Microbiol Biotechnol 2024; 40:181. [PMID: 38668833 DOI: 10.1007/s11274-024-03995-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
In view of the extensive potential applications of chitinase (ChiA) in various fields such as agriculture, environmental protection, medicine, and biotechnology, the development of a high-yielding strain capable of producing chitinase with enhanced activity holds significant importance. The objective of this study was to utilize the extracellular chitinase from Bacillus thuringiensis as the target, and Bacillus licheniformis as the expression host to achieve heterologous expression of ChiA with enhanced activity. Initially, through structural analysis and molecular dynamics simulation, we identified key amino acids to improve the enzymatic performance of chitinase, and the specific activity of chitinase mutant D116N/E118N was 48% higher than that of the natural enzyme, with concomitant enhancements in thermostability and pH stability. Subsequently, the expression elements of ChiA(D116N/E118N) were screened and modified in Bacillus licheniformis, resulting in extracellular ChiA activity reached 89.31 U/mL. Further efforts involved the successful knockout of extracellular protease genes aprE, bprA and epr, along with the gene clusters involved in the synthesis of by-products such as bacitracin and lichenin from Bacillus licheniformis. This led to the development of a recombinant strain, DW2△abelA, which exhibited a remarkable improvement in chitinase activity, reaching 145.56 U/mL. To further improve chitinase activity, a chitinase expression frame was integrated into the genome of DW2△abelA, resulting in a significant increas to 180.26 U/mL. Optimization of fermentation conditions and medium components further boosted shake flask enzyme activity shake flask enzyme activity, achieving 200.28 U/mL, while scale-up fermentation experiments yielded an impressive enzyme activity of 338.79 U/mL. Through host genetic modification, expression optimization and fermentation optimization, a high-yielding ChiA strain was successfully constructed, which will provide a solid foundation for the extracellular production of ChiA.
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Affiliation(s)
- Zhimin Qi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Bo Lei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Min Xiong
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Weijia Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Yongqing Liao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Dongbo Cai
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Xin Ma
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China
| | - Ruibin Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China.
| | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, 368 Youyi Avenue, Wuhan, Hubei, 430062, PR China.
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2
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Martínez-Caballero S, Freton C, Molina R, Bartual SG, Gueguen-Chaignon V, Mercy C, Gago F, Mahasenan KV, Muñoz IG, Lee M, Hesek D, Mobashery S, Hermoso JA, Grangeasse C. Molecular basis of the final step of cell division in Streptococcus pneumoniae. Cell Rep 2023; 42:112756. [PMID: 37418323 PMCID: PMC10434722 DOI: 10.1016/j.celrep.2023.112756] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 05/13/2023] [Accepted: 06/21/2023] [Indexed: 07/09/2023] Open
Abstract
Bacterial cell-wall hydrolases must be tightly regulated during bacterial cell division to prevent aberrant cell lysis and to allow final separation of viable daughter cells. In a multidisciplinary work, we disclose the molecular dialogue between the cell-wall hydrolase LytB, wall teichoic acids, and the eukaryotic-like protein kinase StkP in Streptococcus pneumoniae. After characterizing the peptidoglycan recognition mode by the catalytic domain of LytB, we further demonstrate that LytB possesses a modular organization allowing the specific binding to wall teichoic acids and to the protein kinase StkP. Structural and cellular studies notably reveal that the temporal and spatial localization of LytB is governed by the interaction between specific modules of LytB and the final PASTA domain of StkP. Our data collectively provide a comprehensive understanding of how LytB performs final separation of daughter cells and highlights the regulatory role of eukaryotic-like kinases on lytic machineries in the last step of cell division in streptococci.
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Affiliation(s)
- Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Céline Freton
- Molecular Microbiology and Structural Biochemistry, UMR 5086, Université de Lyon, CNRS, Lyon, France
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Sergio G Bartual
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | | | - Chryslène Mercy
- Molecular Microbiology and Structural Biochemistry, UMR 5086, Université de Lyon, CNRS, Lyon, France
| | - Federico Gago
- Department of Biomedical Sciences & Instituto de Química Médica-CSIC Associated Unit, School of Medicine and Health Sciences, University of Alcalá, 28805 Alcalá de Henares, Spain
| | - Kiran V Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Inés G Muñoz
- Structural Biology Program, Spanish National Cancer Research Center (CNIO), 28029 Madrid, Spain
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Instituto de Química-Física "Rocasolano," Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, UMR 5086, Université de Lyon, CNRS, Lyon, France.
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Wang Y, Jiménez DJ, Zhang Z, van Elsas JD. Functioning of a tripartite lignocellulolytic microbial consortium cultivated under two shaking conditions: a metatranscriptomic study. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:54. [PMID: 36991472 DOI: 10.1186/s13068-023-02289-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 02/25/2023] [Indexed: 03/30/2023]
Abstract
Abstract
Background
In a previous study, shaking speed was found to be an important factor affecting the population dynamics and lignocellulose-degrading activities of a synthetic lignocellulolytic microbial consortium composed of the bacteria Sphingobacterium paramultivorum w15, Citrobacter freundii so4, and the fungus Coniochaeta sp. 2T2.1. Here, the gene expression profiles of each strain in this consortium were examined after growth at two shaking speeds (180 and 60 rpm) at three time points (1, 5 and 13 days).
Results
The results indicated that, at 60 rpm, C. freundii so4 switched, to a large extent, from aerobic to flexible (aerobic/microaerophilic/anaerobic) metabolism, resulting in continued slow growth till late stage. In addition, Coniochaeta sp. 2T2.1 tended to occur to a larger extent in the hyphal form, with genes encoding adhesion proteins being highly expressed. Much like at 180 rpm, at 60 rpm, S. paramultivorum w15 and Coniochaeta sp. 2T2.1 were key players in hemicellulose degradation processes, as evidenced from the respective CAZy-specific transcripts. Coniochaeta sp. 2T2.1 exhibited expression of genes encoding arabinoxylan-degrading enzymes (i.e., of CAZy groups GH10, GH11, CE1, CE5 and GH43), whereas, at 180 rpm, some of these genes were suppressed at early stages of growth. Moreover, C. freundii so4 stably expressed genes that were predicted to encode proteins with (1) β-xylosidase/β-glucosidase and (2) peptidoglycan/chitinase activities, (3) stress response- and detoxification-related proteins. Finally, S. paramultivorum w15 showed involvement in vitamin B2 generation in the early stages across the two shaking speeds, while this role was taken over by C. freundii so4 at late stage at 60 rpm.
Conclusions
We provide evidence that S. paramultivorum w15 is involved in the degradation of mainly hemicellulose and in vitamin B2 production, and C. freundii so4 in the degradation of oligosaccharides or sugar dimers, next to detoxification processes. Coniochaeta sp. 2T2.1 was held to be strongly involved in cellulose and xylan (at early stages), next to lignin modification processes (at later stages). The synergism and alternative functional roles presented in this study enhance the eco-enzymological understanding of the degradation of lignocellulose in this tripartite microbial consortium.
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Biochemical Characterizations of the Putative Endolysin Ecd09610 Catalytic Domain from Clostridioides difficile. Antibiotics (Basel) 2022; 11:antibiotics11081131. [PMID: 36010000 PMCID: PMC9405191 DOI: 10.3390/antibiotics11081131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022] Open
Abstract
Clostridioides difficile is the major pathogen of pseudomembranous colitis, and novel antimicrobial agents are sought after for its treatment. Phage-derived endolysins with species-specific lytic activity have potential as novel antimicrobial agents. We surveyed the genome of C. difficile strain 630 and identified an endolysin gene, Ecd09610, which has an uncharacterized domain at the N-terminus and two catalytic domains that are homologous to glucosaminidase and endopeptidase at the C-terminus. Genes containing the two catalytic domains, the glucosaminidase domain and the endopeptidase domain, were cloned and expressed in Escherichia coli as N-terminal histidine-tagged proteins. The purified domain variants showed lytic activity almost specifically for C. difficile, which has a unique peptide bridge in its peptidoglycan. This species specificity is thought to depend on substrate cleavage activity rather than binding. The domain variants were thermostable, and, notably, the glucosaminidase domain remained active up to 100 °C. In addition, we determined the optimal pH and salt concentrations of these domain variants. Their properties are suitable for formulating a bacteriolytic enzyme as an antimicrobial agent. This lytic enzyme can serve as a scaffold for the construction of high lytic activity mutants with enhanced properties.
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Akram F, Haq IU, Shah FI, Aqeel A, Ahmed Z, Mir AS, Qureshi SS, Raja SI. Genus Thermotoga: A valuable home of multifunctional glycoside hydrolases (GHs) for industrial sustainability. Bioorg Chem 2022; 127:105942. [PMID: 35709577 DOI: 10.1016/j.bioorg.2022.105942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 06/04/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022]
Abstract
Nature is a dexterous and prolific chemist for cataloging a number of hostile niches that are the ideal residence of various thermophiles. Apart from having other species, these subsurface environments are considered a throne of bacterial genus Thermotoga. The genome sequence of Thermotogales encodes complex and incongruent clusters of glycoside hydrolases (GHs), which are superior to their mesophilic counterparts and play a prominent role in various applications due to their extreme intrinsic stability. They have a tremendous capacity to use a wide variety of simple and multifaceted carbohydrates through GHs, formulate fermentative hydrogen and bioethanol at extraordinary yield, and catalyze high-temperature reactions for various biotechnological applications. Nevertheless, no stringent rules exist for the thermo-stabilization of biocatalysts present in the genus Thermotoga. These enzymes endure immense attraction in fundamental aspects of how these polypeptides attain and stabilize their distinctive three-dimensional (3D) structures to accomplish their physiological roles. Moreover, numerous genome sequences from Thermotoga species have revealed a significant fraction of genes most closely related to those of archaeal species, thus firming a staunch belief of lateral gene transfer mechanism. However, the question of its magnitude is still in its infancy. In addition to GHs, this genus is a paragon of encapsulins which carry pharmacological and industrial significance in the field of life sciences. This review highlights an intricate balance between the genomic organizations, factors inducing the thermostability, and pharmacological and industrial applications of GHs isolated from genus Thermotoga.
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Affiliation(s)
- Fatima Akram
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan.
| | - Ikram Ul Haq
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan; Pakistan Academy of Science, Islamabad, Pakistan
| | - Fatima Iftikhar Shah
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Amna Aqeel
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Zeeshan Ahmed
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Azka Shahzad Mir
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Sumbal Sajid Qureshi
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Saleha Ibadat Raja
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
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6
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Roig-Zamboni V, Barelier S, Dixon R, Galley NF, Ghanem A, Nguyen QP, Cahuzac H, Salamaga B, Davis PJ, Bourne Y, Mesnage S, Vincent F. Molecular basis for substrate recognition and septum cleavage by AtlA, the major N-acetylglucosaminidase of Enterococcus faecalis. J Biol Chem 2022; 298:101915. [PMID: 35398351 PMCID: PMC9108991 DOI: 10.1016/j.jbc.2022.101915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 11/26/2022] Open
Abstract
The cleavage of septal peptidoglycan at the end of cell division facilitates the separation of the two daughter cells. The hydrolases involved in this process (called autolysins) are potentially lethal enzymes that can cause cell death; their activity, therefore, must be tightly controlled during cell growth. In Enterococcus faecalis, the N-acetylglucosaminidase AtlA plays a predominant role in cell separation. atlA mutants form long cell chains and are significantly less virulent in the zebrafish model of infection. The attenuated virulence of atlA mutants is underpinned by a limited dissemination of bacterial chains in the host organism and a more efficient uptake by phagocytes that clear the infection. AtlA has structural homologs in other important pathogens, such as Listeria monocytogenes and Salmonella typhimurium, and therefore represents an attractive model to design new inhibitors of bacterial pathogenesis. Here, we provide a 1.45 Å crystal structure of the E. faecalis AtlA catalytic domain that reveals a closed conformation of a conserved β-hairpin and a complex network of hydrogen bonds that bring two catalytic residues to the ideal distance for an inverting mechanism. Based on the model of the AtlA-substrate complex, we identify key residues critical for substrate recognition and septum cleavage during bacterial growth. We propose that this work will provide useful information for the rational design of specific inhibitors targeting this enterococcal virulence factor and its orthologs in other pathogens.
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Affiliation(s)
| | | | - Robert Dixon
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Amani Ghanem
- CNRS, Aix Marseille University, AFMB, Marseille, France
| | | | - Héloize Cahuzac
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | | | - Peter J Davis
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Yves Bourne
- CNRS, Aix Marseille University, AFMB, Marseille, France
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom.
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Haubrich BA, Nayyab S, Gallati M, Hernandez J, Williams C, Whitman A, Zimmerman T, Li Q, Chen Y, Zhou CZ, Basu A, Reid CW. Inhibition of Streptococcus pneumoniae growth by masarimycin. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35467499 DOI: 10.1099/mic.0.001182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Despite renewed interest, development of chemical biology methods to study peptidoglycan metabolism has lagged in comparison to the glycobiology field in general. To address this, a panel of diamides were screened against the Gram-positive bacterium Streptococcus pneumoniae to identify inhibitors of bacterial growth. The screen identified the diamide masarimycin as a bacteriostatic inhibitor of S. pneumoniae growth with an MIC of 8 µM. The diamide inhibited detergent-induced autolysis in a concentration-dependent manner, indicating perturbation of peptidoglycan degradation as the mode-of-action. Cell based screening of masarimycin against a panel of autolysin mutants, identified a higher MIC against a ΔlytB strain lacking an endo-N-acetylglucosaminidase involved in cell division. Subsequent biochemical and phenotypic analyses suggested that the higher MIC was due to an indirect interaction with LytB. Further analysis of changes to the cell surface in masarimycin treated cells identified the overexpression of several moonlighting proteins, including elongation factor Tu which is implicated in regulating cell shape. Checkerboard assays using masarimycin in concert with additional antibiotics identified an antagonistic relationship with the cell wall targeting antibiotic fosfomycin, which further supports a cell wall mode-of-action.
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Affiliation(s)
- Brad A Haubrich
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Department of Basic Sciences, Touro University Nevada, College of Osteopathic Medicine, Henderson, NV 89014, USA
| | - Saman Nayyab
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Amherst Department of Molecular and Cellular Biology, University of Massachusetts, 230 Stockbridge Rd Amherst, MA, USA
| | - Mika Gallati
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Jazmeen Hernandez
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Caroline Williams
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Andrew Whitman
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Tahl Zimmerman
- Department of Family and Consumer Sciences, North Carolina A&T State University, Greensboro, NC, USA
| | - Qiong Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Yuxing Chen
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Cong-Zhao Zhou
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Amit Basu
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Christopher W Reid
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
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8
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Kumar S, Bansal K, Sethi SK. Comparative genomics analysis of genus Leuconostoc resolves its taxonomy and elucidates its biotechnological importance. Food Microbiol 2022; 106:104039. [DOI: 10.1016/j.fm.2022.104039] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 04/04/2022] [Accepted: 04/12/2022] [Indexed: 11/27/2022]
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9
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Cernooka E, Rumnieks J, Zrelovs N, Tars K, Kazaks A. Diversity of the lysozyme fold: structure of the catalytic domain from an unusual endolysin encoded by phage Enc34. Sci Rep 2022; 12:5005. [PMID: 35322067 PMCID: PMC8943055 DOI: 10.1038/s41598-022-08765-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 03/10/2022] [Indexed: 12/02/2022] Open
Abstract
Endolysins are bacteriophage-encoded peptidoglycan-degrading enzymes with potential applications for treatment of multidrug-resistant bacterial infections. Hafnia phage Enc34 encodes an unusual endolysin with an N-terminal enzymatically active domain and a C-terminal transmembrane domain. The catalytic domain of the endolysin belongs to the conserved protein family PHA02564 which has no recognizable sequence similarity to other known endolysin types. Turbidity reduction assays indicate that the Enc34 enzyme is active against peptidoglycan from a variety of Gram-negative bacteria including the opportunistic pathogen Pseudomonas aeruginosa PAO1. The crystal structure of the catalytic domain of the Enc34 endolysin shows a distinctive all-helical architecture that distantly resembles the α-lobe of the lysozyme fold. Conserved catalytically important residues suggest a shared evolutionary history between the Enc34 endolysin and GH73 and GH23 family glycoside hydrolases and propose a molecular signature for substrate cleavage for a large group of peptidoglycan-degrading enzymes.
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Affiliation(s)
- Elina Cernooka
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga, 1067, Latvia
| | - Janis Rumnieks
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga, 1067, Latvia
| | - Nikita Zrelovs
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga, 1067, Latvia
| | - Kaspars Tars
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga, 1067, Latvia.,Faculty of Biology, University of Latvia, Jelgavas 1, Riga, 1004, Latvia
| | - Andris Kazaks
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga, 1067, Latvia.
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Harvey DJ. ANALYSIS OF CARBOHYDRATES AND GLYCOCONJUGATES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY: AN UPDATE FOR 2015-2016. MASS SPECTROMETRY REVIEWS 2021; 40:408-565. [PMID: 33725404 DOI: 10.1002/mas.21651] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/24/2020] [Indexed: 06/12/2023]
Abstract
This review is the ninth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2016. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented over 30 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show no sign of deminishing. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
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11
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Shirakawa D, Wakinaka T, Watanabe J. Identification of the putative N-acetylglucosaminidase CseA associated with daughter cell separation in Tetragenococcus halophilus. Biosci Biotechnol Biochem 2020; 84:1724-1735. [PMID: 32448081 DOI: 10.1080/09168451.2020.1764329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The lactic acid bacterium Tetragenococcus halophilus, which is used as a starter to brew soy sauce, comprises both cluster-forming strains and dispersed strains. The cluster-forming strains are industrially useful for obtaining clear soy sauce, because the cell clusters are trapped by filter cloth when the soy sauce mash is pressed. However, the molecular mechanism underlying cell cluster formation is unknown. Whole genome sequence analysis and subsequent target sequence analysis revealed that the cluster-forming strains commonly have functional defects in N-acetylglucosaminidase CseA, a peptidoglycan hydrolase. CseA is a multimodular protein that harbors a GH73 domain and six peptidoglycan-binding LysM domains. Recombinant CseA hydrolyzed peptidoglycan and promoted cell separation. Functional analysis of truncated CseA derivatives revealed that the LysM domains play an important role in efficient peptidoglycan degradation and cell separation. Taken together, the results of this study identify CseA as a factor that greatly affects the cluster formation in T. halophilus.
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Affiliation(s)
| | | | - Jun Watanabe
- Manufacturing Division, Yamasa Corporation , Chiba, Japan
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12
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Domain sliding of two Staphylococcus aureus N-acetylglucosaminidases enables their substrate-binding prior to its catalysis. Commun Biol 2020; 3:178. [PMID: 32313083 PMCID: PMC7170848 DOI: 10.1038/s42003-020-0911-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 03/23/2020] [Indexed: 12/22/2022] Open
Abstract
To achieve productive binding, enzymes and substrates must align their geometries to complement each other along an entire substrate binding site, which may require enzyme flexibility. In pursuit of novel drug targets for the human pathogen S. aureus, we studied peptidoglycan N-acetylglucosaminidases, whose structures are composed of two domains forming a V-shaped active site cleft. Combined insights from crystal structures supported by site-directed mutagenesis, modeling, and molecular dynamics enabled us to elucidate the substrate binding mechanism of SagB and AtlA-gl. This mechanism requires domain sliding from the open form observed in their crystal structures, leading to polysaccharide substrate binding in the closed form, which can enzymatically process the bound substrate. We suggest that these two hydrolases must exhibit unusual extents of flexibility to cleave the rigid structure of a bacterial cell wall.
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13
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Vijayaraghavan J, Kumar V, Krishnan NP, Kaufhold RT, Zeng X, Lin J, van den Akker F. Structural studies and molecular dynamics simulations suggest a processive mechanism of exolytic lytic transglycosylase from Campylobacter jejuni. PLoS One 2018; 13:e0197136. [PMID: 29758058 PMCID: PMC5951611 DOI: 10.1371/journal.pone.0197136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/26/2018] [Indexed: 11/21/2022] Open
Abstract
The bacterial soluble lytic transglycosylase (LT) breaks down the peptidoglycan (PG) layer during processes such as cell division. We present here crystal structures of the soluble LT Cj0843 from Campylobacter jejuni with and without bulgecin A inhibitor in the active site. Cj0843 has a doughnut shape similar but not identical to that of E. coli SLT70. The C-terminal catalytic domain is preceded by an L-domain, a large helical U-domain, a flexible linker, and a small N-terminal NU-domain. The flexible linker allows the NU-domain to reach over and complete the circular shape, using residues conserved in the Epsilonproteobacteria LT family. The inner surface of the Cj0843 doughnut is mostly positively charged including a pocket that has 8 Arg/Lys residues. Molecular dynamics simulations with PG strands revealed a potential functional role for this pocket in anchoring the negatively charged terminal tetrapeptide of the PG during several steps in the reaction including homing and aligning the PG strand for exolytic cleavage, and subsequent ratcheting of the PG strand to enhance processivity in degrading PG strands.
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Affiliation(s)
- Jagamya Vijayaraghavan
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Vijay Kumar
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Nikhil P. Krishnan
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Ross T. Kaufhold
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Ximin Zeng
- Institute of agriculture, University of Tennessee, Knoxville, TN, United States of America
| | - Jun Lin
- Institute of agriculture, University of Tennessee, Knoxville, TN, United States of America
| | - Focco van den Akker
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
- * E-mail:
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14
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Borišek J, Pintar S, Ogrizek M, Turk D, Perdih A, Novič M. A Water-Assisted Catalytic Mechanism in Glycoside Hydrolases Demonstrated on the Staphylococcus aureus Autolysin E. ACS Catal 2018. [DOI: 10.1021/acscatal.8b01064] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jure Borišek
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Sara Pintar
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Jozef Stefan International Postgraduate School, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Mitja Ogrizek
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Dušan Turk
- Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Andrej Perdih
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| | - Marjana Novič
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
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15
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Enzymatic properties of β-N-acetylglucosaminidases. Appl Microbiol Biotechnol 2017; 102:93-103. [PMID: 29143882 DOI: 10.1007/s00253-017-8624-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 01/27/2023]
Abstract
β-N-Acetylglucosaminidases (GlcNAcases) hydrolyse N-acetylglucosamine-containing oligosaccharides and proteins. These enzymes produce N-acetylglucosamine (GlcNAc) and have a wide range of promising applications in the food, energy, and pharmaceutical industries, such as synergistic degradation of chitin with endo-chitinases and using GlcNAc to produce sialic acid, bioethanol, single-cell proteins, and pharmaceutical therapeutics. GlcNAcases also play an important role in the dynamic balance of cellular O-linked GlcNAc levels, catabolism of ganglioside storage in Tay-Sachs disease, and bacterial cell wall recycling and flagellar assembly. In view of these important biological functions and the wide range of industrial applications of GlcNAcases, this review aims to provide a better understanding of various advances for these enzymes. It focuses on enzymatic properties of GlcNAcases, including substrate specificity, catalytic activity, pH optimum, temperature optimum, thermostability, the effects of various metal ions and organic reagents, and transglycosylation.
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16
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Olczak A, Cianci M. The signal-to-noise ratio in SAD experiments. CRYSTALLOGR REV 2017. [DOI: 10.1080/0889311x.2017.1386182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Andrzej Olczak
- Institute of General and Ecological Chemistry, Lodz University of Technology, Lodz, Poland
| | - Michele Cianci
- Department of Agricultural, Food and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy
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17
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Nayyab S, O’Connor M, Brewster J, Gravier J, Jamieson M, Magno E, Miller RD, Phelan D, Roohani K, Williard P, Basu A, Reid CW. Diamide Inhibitors of the Bacillus subtilis N-Acetylglucosaminidase LytG That Exhibit Antibacterial Activity. ACS Infect Dis 2017; 3:421-427. [PMID: 28448118 DOI: 10.1021/acsinfecdis.7b00005] [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] [Indexed: 01/03/2023]
Abstract
N-Acetylglucosaminidases (GlcNAcases) play an important role in the remodeling and recycling of bacterial peptidoglycan by degrading the polysaccharide backbone. Genetic deletions of autolysins can impair cell division and growth, suggesting an opportunity for using small molecule autolysin inhibitors both as tools for studying the chemical biology of autolysins and also as antibacterial agents. We report here the synthesis and evaluation of a panel of diamides that inhibit the growth of Bacillus subtilis. Two compounds, fgkc (21) and fgka (5), were found to be potent inhibitors (MIC 3.8 ± 1.0 and 21.3 ± 0.1 μM, respectively). These compounds inhibit the B. subtilis family 73 glycosyl hydrolase LytG, an exo GlcNAcase. Phenotypic analysis of fgkc (21)-treated cells demonstrates a propensity for cells to form linked chains, suggesting impaired cell growth and division.
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Affiliation(s)
- Saman Nayyab
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Mary O’Connor
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Jennifer Brewster
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - James Gravier
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Mitchell Jamieson
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Ethan Magno
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Ryan D. Miller
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Drew Phelan
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Keyana Roohani
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
| | - Paul Williard
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Amit Basu
- Department of Chemistry, Box H, Brown University, Providence, Rhode Island 02912, United States
| | - Christopher W. Reid
- Department
of Science and Technology, Bryant University, Smithfield, Rhode Island 02917, United States
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18
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Tamai E, Sekiya H, Goda E, Makihata N, Maki J, Yoshida H, Kamitori S. Structural and biochemical characterization of the Clostridium perfringens autolysin catalytic domain. FEBS Lett 2016; 591:231-239. [PMID: 27926788 DOI: 10.1002/1873-3468.12515] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/17/2016] [Accepted: 11/26/2016] [Indexed: 11/08/2022]
Abstract
Bacterial autolysins can partially hydrolyze cell wall peptidoglycans into small sections to regulate cell separation/division and the growth phase. Clostridium perfringens autolysin (Acp) has an N-terminal cell wall-binding domain and a C-terminal catalytic domain with glucosaminidase activity that belongs to the glycoside hydrolase 73 family. Here, we determined the X-ray structure of the Acp catalytic domain (AcpCD) at 1.76 Å resolution. AcpCD has a unique crescent-shaped structure, forming a deep groove for substrate-binding at the center of the protein. The modeling study of the enzyme/substrate complex demonstrated that the length of the substrate-binding groove is closely related to the glucosaminidase activity. Mutagenesis analysis showed that AcpCD likely adopts a neighboring-group mechanism for the catalytic reaction.
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Affiliation(s)
- Eiji Tamai
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Bunkyo-cho, Ehime, Japan.,Life Science Research Center and Faculty of Medicine, Kagawa University, Miki-cho, Kita-gun, Kagawa, Japan
| | - Hiroshi Sekiya
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Bunkyo-cho, Ehime, Japan
| | - Eri Goda
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Bunkyo-cho, Ehime, Japan
| | - Nahomi Makihata
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Bunkyo-cho, Ehime, Japan
| | - Jun Maki
- Department of Infectious Disease, College of Pharmaceutical Science, Matsuyama University, Bunkyo-cho, Ehime, Japan
| | - Hiromi Yoshida
- Life Science Research Center and Faculty of Medicine, Kagawa University, Miki-cho, Kita-gun, Kagawa, Japan
| | - Shigehiro Kamitori
- Life Science Research Center and Faculty of Medicine, Kagawa University, Miki-cho, Kita-gun, Kagawa, Japan
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19
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Structural and Biochemical Insights into the Peptidoglycan Hydrolase Domain of FlgJ from Salmonella typhimurium. PLoS One 2016; 11:e0149204. [PMID: 26871950 PMCID: PMC4752226 DOI: 10.1371/journal.pone.0149204] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 01/28/2016] [Indexed: 11/19/2022] Open
Abstract
FlgJ is a glycoside hydrolase (GH) enzyme belonging to the Carbohydrate Active enZyme (CAZy) family GH73. It facilitates passage of the bacterial flagellum through the peptidoglycan (PG) layer by cleaving the β-1,4 glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid sugars that comprise the glycan strands of PG. Here we describe the crystal structure of the GH domain of FlgJ from bacterial pathogen Salmonella typhimurium (StFlgJ). Interestingly, the active site of StFlgJ was blocked by the C-terminal α-helix of a neighbouring symmetry mate and a β-hairpin containing the putative catalytic glutamic acid residue Glu223 was poorly resolved and could not be completely modeled into the electron density, suggesting it is flexible. Previous reports have shown that the GH73 enzyme Auto from Listeria monocytogenes is inhibited by an N-terminal α-helix that may occlude the active site in similar fashion. To investigate if the C-terminus of StFlgJ inhibits GH activity, the glycolytic activity of StFlgJ was assessed with and without the C-terminal α-helix. The GH activity of StFlgJ was unaffected by the presence or absence of the α-helix, suggesting it is not involved in regulating activity. Removal of the C-terminal α-helix did, however, allow a crystal structure of the domain to be obtained where the flexible β-hairpin containing residue Glu223 was entirely resolved. The β-hairpin was positioned such that the active site groove was fully solvent-exposed, placing Glu223 nearly 21.6 Å away from the putative general acid/base residue Glu184, which is too far apart for these two residues to coordinate glycosidic bond hydrolysis. The mobile nature of the StFlgJ β-hairpin is consistent with structural studies of related GH73 enzymes, suggesting that a dynamic active site may be common to many GH73 enzymes, in which the active site opens to capture substrate and then closes to correctly orient active site residues for catalysis.
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20
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Herlihey FA, Clarke AJ. Controlling Autolysis During Flagella Insertion in Gram-Negative Bacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 925:41-56. [PMID: 27722959 DOI: 10.1007/5584_2016_52] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The flagellum is an important macromolecular machine for many pathogenic bacteria. It is a hetero-oligomeric structure comprised of three major sub-structures: basal body, hook and thin helical filament. An important step during flagellum assembly is the localized and controlled degradation of the peptidoglycan sacculus to allow for the insertion of the rod as well as to facilitate anchoring for proper motor function. The peptidoglycan lysis events require specialized lytic enzymes, β-N-acetylglucosaminidases and lytic transglycosylases, which differ in flagellated proteobacteria. Due to their autolytic activity, these enzymes need to be controlled in order to prevent cellular lysis. This review summarizes are current understanding of the peptidoglycan lysis events required for flagellum assembly and motility with a main focus on Gram-negative bacteria.
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Affiliation(s)
- Francesca A Herlihey
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G2W1, Canada
| | - Anthony J Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G2W1, Canada.
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21
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Identification of the nucleophile catalytic residue of GH51 α-L-arabinofuranosidase from Pleurotus ostreatus. AMB Express 2015; 5:79. [PMID: 26690659 PMCID: PMC4686458 DOI: 10.1186/s13568-015-0164-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/12/2015] [Indexed: 11/21/2022] Open
Abstract
In this study, the recombinant α-l-arabinofuranosidase from the fungus Pleurotus ostreatus (rPoAbf) was subjected to site-directed mutagenesis in order to identify the catalytic nucleophile residue. Based on bioinformatics and homology modelling analyses, E449 was revealed to be the potential nucleophilic residue. Thus, the mutant E449G of PoAbf was recombinantly expressed in Pichia pastoris and its recombinant expression level and reactivity were investigated in comparison to the wild-type. The design of a suitable set of hydrolysis experiments in the presence or absence of alcoholic arabinosyl acceptors and/or formate salts allowed to unambiguously identify the residue E449 as the nucleophile residue involved in the retaining mechanism of this GH51 arabinofuranosidase. 1H NMR analysis was applied for the identification of the products and the assignement of their anomeric configuration.
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22
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Substrate recognition and catalysis by LytB, a pneumococcal peptidoglycan hydrolase involved in virulence. Sci Rep 2015; 5:16198. [PMID: 26537571 PMCID: PMC4633669 DOI: 10.1038/srep16198] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022] Open
Abstract
Streptococcus pneumoniae is a major cause of life-threatening diseases worldwide. Here we provide an in-depth functional characterization of LytB, the peptidoglycan hydrolase responsible for physical separation of daughter cells. Identified herein as an N-acetylglucosaminidase, LytB is involved also in colonization and invasion of the nasopharynx, biofilm formation and evasion of host immunity as previously demonstrated. We have shown that LytB cleaves the GlcNAc-β-(1,4)-MurNAc glycosidic bond of peptidoglycan building units. The hydrolysis occurs at sites with fully acetylated GlcNAc moieties, with preference for uncross-linked muropeptides. The necessity of GlcN acetylation and the presence of a single acidic moiety (Glu585) essential for catalysis strongly suggest a substrate-assisted mechanism with anchimeric assistance of the acetamido group of GlcNAc moieties. Additionally, modelling of the catalytic region bound to a hexasaccharide tripentapeptide provided insights into substrate-binding subsites and peptidoglycan recognition. Besides, cell-wall digestion products and solubilisation rates might indicate a tight control of LytB activity to prevent unrestrained breakdown of the cell wall. Choline-independent localization at the poles of the cell, mediated by the choline-binding domain, peptidoglycan modification, and choline-mediated (lipo)teichoic-acid attachment contribute to the high selectivity of LytB. Moreover, so far unknown chitin hydrolase and glycosyltransferase activities were detected using GlcNAc oligomers as substrate.
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23
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Altegoer F, Bange G. Undiscovered regions on the molecular landscape of flagellar assembly. Curr Opin Microbiol 2015; 28:98-105. [PMID: 26490009 DOI: 10.1016/j.mib.2015.08.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/27/2015] [Accepted: 08/28/2015] [Indexed: 01/10/2023]
Abstract
The bacterial flagellum is a motility structure and one of the most complicated motors in the biosphere. A flagellum consists of several dozens of building blocks in different stoichiometries and extends from the cytoplasm to the extracellular space. Flagellar biogenesis follows a strict spatio-temporal regime that is guided by a plethora of flagellar assembly factors and chaperones. The goal of this review is to summarize our current structural and mechanistic knowledge of this intricate process and to identify the undiscovered regions on the molecular landscape of flagellar assembly.
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Affiliation(s)
- Florian Altegoer
- LOEWE Center for Synthetic Microbiology & Department of Chemistry, Philipps University Marburg, Hans-Meerwein-Strasse, C7, 35043 Marburg, Germany
| | - Gert Bange
- LOEWE Center for Synthetic Microbiology & Department of Chemistry, Philipps University Marburg, Hans-Meerwein-Strasse, C7, 35043 Marburg, Germany.
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24
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Jiménez DJ, Maruthamuthu M, van Elsas JD. Metasecretome analysis of a lignocellulolytic microbial consortium grown on wheat straw, xylan and xylose. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:199. [PMID: 26628913 PMCID: PMC4666044 DOI: 10.1186/s13068-015-0387-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/16/2015] [Indexed: 05/09/2023]
Abstract
BACKGROUND Synergistic action of different enzymes is required to complete the degradation of plant biomass in order to release sugars which are useful for biorefining. However, the use of single strains is often not efficient, as crucial parts of the required enzymatic machinery can be absent. The use of microbial consortia bred on plant biomass is a way to overcome this hurdle. In these, secreted proteins constitute sources of relevant enzyme cocktails. Extensive analyses of the proteins secreted by effective microbial consortia will contribute to a better understanding of the mechanism of lignocellulose degradation. RESULTS Here, we report an analysis of the proteins secreted by a microbial consortium (metasecretome) that was grown on either wheat straw (RWS), xylose or xylan as the carbon sources. Liquid chromatography-tandem mass spectrometry was used to analyze the proteins in the supernatants. Totals of 768 (RWS), 477 (xylose) and 103 (xylan) proteins were identified and taxonomically and functionally classified. In RWS, the proteins were mostly affiliated with Sphingobacterium-like consortium members (~50 %). Specific abundant protein clusters were predicted to be involved in polysaccharide transport and/or sensing (TonB-dependent receptors). In addition, proteins predicted to degrade plant biomass, i.e. endo-1,4-beta-xylanases, alpha-l-arabinofuranosidases and alpha-l-fucosidases, were prominent. In the xylose-driven consortium, most secreted proteins were affiliated with those from Enterobacteriales (mostly Klebsiella species), whereas in the xylan-driven one, they were related to Flavobacterium-like ones. Notably, the metasecretomes of the consortia growing on xylose and xylan contained proteins involved in diverse metabolic functions (e.g. membrane proteins, isomerases, dehydrogenases and oxidoreductases). CONCLUSIONS An analysis of the metasecretomes of microbial consortia originating from the same source consortium and subsequently bred on three different carbon sources indicated that the major active microorganisms in the three final consortia differed. Importantly, diverse glycosyl hydrolases, predicted to be involved in (hemi)cellulose degradation (e.g. of CAZy families GH3, GH10, GH43, GH51, GH67 and GH95), were identified in the RWS metasecretome. Based on these results, we catalogued the RWS consortium as a true microbial enzyme factory that constitute an excellent source for the production of an efficient enzyme cocktail for the pretreatment of plant biomass.
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Affiliation(s)
- Diego Javier Jiménez
- Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Mukil Maruthamuthu
- Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands
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