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Bukowska-Faniband E, Hederstedt L. Transpeptidase activity of penicillin-binding protein SpoVD in peptidoglycan synthesis conditionally depends on the disulfide reductase StoA. Mol Microbiol 2017; 105:98-114. [PMID: 28383125 DOI: 10.1111/mmi.13689] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2017] [Indexed: 11/28/2022]
Abstract
Endospore cortex peptidoglycan synthesis is not required for bacterial growth but essential for endospore heat resistance. It therefore constitutes an amenable system for research on peptidoglycan biogenesis. The Bacillus subtilis sporulation-specific class B penicillin-binding protein (PBP) SpoVD and many homologous PBPs contain two conserved cysteine residues of unknown function in the transpeptidase domain - one as residue x in the SxN catalytic site motif and the other in a flexible loop near the catalytic site. A disulfide bond between these residues blocks the function of SpoVD in cortex synthesis. With a combination of experiments with purified proteins and B. subtilis mutant cells, it was shown that in active SpoVD the two cysteine residues most probably interact by hydrogen bonding and that this is important for peptidoglycan synthesis in vivo. It was furthermore demonstrated that the sporulation-specific thiol-disulfide oxidoreductase StoA reduces SpoVD and that requirement of StoA for cortex synthesis can be suppressed by two completely different types of structural alterations in SpoVD. It is concluded that StoA plays a critical role mainly during maturation of SpoVD in the forespore outer membrane. The findings advance our understanding of essential PBPs and redox control of extra-cytoplasmic protein disulfides in bacterial cells.
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Affiliation(s)
- Ewa Bukowska-Faniband
- Microbiology Group, Department of Biology, Lund University, Sölvegatan 35, Lund, SE- 223 62, Sweden
| | - Lars Hederstedt
- Microbiology Group, Department of Biology, Lund University, Sölvegatan 35, Lund, SE- 223 62, Sweden
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2
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Davey L, Halperin SA, Lee SF. Thiol-Disulfide Exchange in Gram-Positive Firmicutes. Trends Microbiol 2016; 24:902-915. [PMID: 27426970 DOI: 10.1016/j.tim.2016.06.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/08/2016] [Accepted: 06/28/2016] [Indexed: 11/17/2022]
Abstract
Extracytoplasmic thiol-disulfide oxidoreductases (TDORs) catalyze the oxidation, reduction, and isomerization of protein disulfide bonds. Although these processes have been characterized in Gram-negative bacteria, the majority of Gram-positive TDORs have only recently been discovered. Results from recent studies have revealed distinct trends in the types of TDOR used by different groups of Gram-positive bacteria, and in their biological functions. Actinobacteria TDORs can be essential for viability, while Firmicute TDORs influence various physiological processes, including protein stability, oxidative stress resistance, bacteriocin production, and virulence. In this review we discuss the diverse extracytoplasmic TDORs used by Gram-positive bacteria, with a focus on Gram-positive Firmicutes.
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Affiliation(s)
- Lauren Davey
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, B3H 1X5 Canada; Canadian Center for Vaccinology, Dalhousie University and the IWK Health Centre, Halifax, NS, B3K 6R8 Canada
| | - Scott A Halperin
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, B3H 1X5 Canada; Canadian Center for Vaccinology, Dalhousie University and the IWK Health Centre, Halifax, NS, B3K 6R8 Canada; Department of Pediatrics, Faculty of Medicine, Dalhousie University and the IWK Health Centre, Halifax, NS, B3K 6R8 Canada
| | - Song F Lee
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, B3H 1X5 Canada; Canadian Center for Vaccinology, Dalhousie University and the IWK Health Centre, Halifax, NS, B3K 6R8 Canada; Department of Pediatrics, Faculty of Medicine, Dalhousie University and the IWK Health Centre, Halifax, NS, B3K 6R8 Canada; Department of Applied Oral Sciences, Faculty of Dentistry, Dalhousie University, Halifax, NS, B3H 4R2 Canada.
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3
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Reardon-Robinson ME, Osipiuk J, Chang C, Wu C, Jooya N, Joachimiak A, Das A, Ton-That H. A Disulfide Bond-forming Machine Is Linked to the Sortase-mediated Pilus Assembly Pathway in the Gram-positive Bacterium Actinomyces oris. J Biol Chem 2015; 290:21393-405. [PMID: 26170452 PMCID: PMC4571867 DOI: 10.1074/jbc.m115.672253] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Indexed: 12/30/2022] Open
Abstract
Export of cell surface pilins in Gram-positive bacteria likely occurs by the translocation of unfolded precursor polypeptides; however, how the unfolded pilins gain their native conformation is presently unknown. Here, we present physiological studies to demonstrate that the FimA pilin of Actinomyces oris contains two disulfide bonds. Alanine substitution of cysteine residues forming the C-terminal disulfide bridge abrogates pilus assembly, in turn eliminating biofilm formation and polymicrobial interaction. Transposon mutagenesis of A. oris yielded a mutant defective in adherence to Streptococcus oralis, and revealed the essential role of a vitamin K epoxide reductase (VKOR) gene in pilus assembly. Targeted deletion of vkor results in the same defects, which are rescued by ectopic expression of VKOR, but not a mutant containing an alanine substitution in its conserved CXXC motif. Depletion of mdbA, which encodes a membrane-bound thiol-disulfide oxidoreductase, abrogates pilus assembly and alters cell morphology. Remarkably, overexpression of MdbA or a counterpart from Corynebacterium diphtheriae, rescues the Δvkor mutant. By alkylation assays, we demonstrate that VKOR is required for MdbA reoxidation. Furthermore, crystallographic studies reveal that A. oris MdbA harbors a thioredoxin-like fold with the conserved CXXC active site. Consistently, each MdbA enzyme catalyzes proper disulfide bond formation within FimA in vitro that requires the catalytic CXXC motif. Because the majority of signal peptide-containing proteins encoded by A. oris possess multiple Cys residues, we propose that MdbA and VKOR constitute a major folding machine for the secretome of this organism. This oxidative protein folding pathway may be a common feature in Actinobacteria.
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Affiliation(s)
- Melissa E. Reardon-Robinson
- From the Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030
| | - Jerzy Osipiuk
- the Department of Biosciences, Midwest Center for Structural Genomics, and ,the Department of Biosciences, Structural Biology Center, Argonne National Laboratory, Argonne, Illinois 60439, and
| | - Chungyu Chang
- From the Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030
| | - Chenggang Wu
- From the Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030
| | - Neda Jooya
- From the Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030
| | - Andrzej Joachimiak
- the Department of Biosciences, Midwest Center for Structural Genomics, and ,the Department of Biosciences, Structural Biology Center, Argonne National Laboratory, Argonne, Illinois 60439, and
| | - Asis Das
- the Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - Hung Ton-That
- From the Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston, Texas 77030,
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4
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Dong Y, Qiu X, Shaw N, Xu Y, Sun Y, Li X, Li J, Rao Z. Molecular basis for the inhibition of β-hydroxyacyl-ACP dehydratase HadAB complex from Mycobacterium tuberculosis by flavonoid inhibitors. Protein Cell 2015; 6:504-17. [PMID: 26081470 PMCID: PMC4491049 DOI: 10.1007/s13238-015-0181-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/08/2015] [Indexed: 11/28/2022] Open
Abstract
Dehydration is one of the key steps in the biosynthesis of mycolic acids and is vital to the growth of Mycobacterium tuberculosis (Mtb). Consequently, stalling dehydration cures tuberculosis (TB). Clinically used anti-TB drugs like thiacetazone (TAC) and isoxyl (ISO) as well as flavonoids inhibit the enzyme activity of the β-hydroxyacyl-ACP dehydratase HadAB complex. How this inhibition is exerted, has remained an enigma for years. Here, we describe the first crystal structures of the MtbHadAB complex bound with flavonoid inhibitor butein, 2',4,4'-trihydroxychalcone or fisetin. Despite sharing no sequence identity from Blast, HadA and HadB adopt a very similar hotdog fold. HadA forms a tight dimer with HadB in which the proteins are sitting side-by-side, but are oriented anti-parallel. While HadB contributes the catalytically critical His-Asp dyad, HadA binds the fatty acid substrate in a long channel. The atypical double hotdog fold with a single active site formed by MtbHadAB gives rise to a long, narrow cavity that vertically traverses the fatty acid binding channel. At the base of this cavity lies Cys61, which upon mutation to Ser confers drug-resistance in TB patients. We show that inhibitors bind in this cavity and protrude into the substrate binding channel. Thus, inhibitors of MtbHadAB exert their effect by occluding substrate from the active site. The unveiling of this mechanism of inhibition paves the way for accelerating development of next generation of anti-TB drugs.
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Affiliation(s)
- Yu Dong
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
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5
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Assessing the progress of Mycobacterium tuberculosis H37Rv structural genomics. Tuberculosis (Edinb) 2015; 95:131-6. [DOI: 10.1016/j.tube.2014.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/05/2014] [Accepted: 12/17/2014] [Indexed: 11/19/2022]
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6
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Um SH, Kim JS, Lee K, Ha NC. Structure of a DsbF homologue from Corynebacterium diphtheriae. Acta Crystallogr F Struct Biol Commun 2014; 70:1167-72. [PMID: 25195886 PMCID: PMC4157413 DOI: 10.1107/s2053230x14016355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/15/2014] [Indexed: 11/10/2022] Open
Abstract
Disulfide-bond formation, mediated by the Dsb family of proteins, is important in the correct folding of secreted or extracellular proteins in bacteria. In Gram-negative bacteria, disulfide bonds are introduced into the folding proteins in the periplasm by DsbA. DsbE from Escherichia coli has been implicated in the reduction of disulfide bonds in the maturation of cytochrome c. The Gram-positive bacterium Mycobacterium tuberculosis encodes DsbE and its homologue DsbF, the structures of which have been determined. However, the two mycobacterial proteins are able to oxidatively fold a protein in vitro, unlike DsbE from E. coli. In this study, the crystal structure of a DsbE or DsbF homologue protein from Corynebacterium diphtheriae has been determined, which revealed a thioredoxin-like domain with a typical CXXC active site. Structural comparison with M. tuberculosis DsbF would help in understanding the function of the C. diphtheriae protein.
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Affiliation(s)
- Si-Hyeon Um
- Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Manufacturing Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Jin-Sik Kim
- Department of Manufacturing Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, Republic of Korea
| | - Nam-Chul Ha
- Department of Agricultural Biotechnology, Center for Food and Bioconvergence, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
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7
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Chim N, Johnson PM, Goulding CW. Insights into redox sensing metalloproteins in Mycobacterium tuberculosis. J Inorg Biochem 2014; 133:118-26. [PMID: 24314844 PMCID: PMC3959581 DOI: 10.1016/j.jinorgbio.2013.11.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/07/2013] [Accepted: 11/08/2013] [Indexed: 12/29/2022]
Abstract
Mycobacterium tuberculosis, the pathogen that causes tuberculosis, has evolved sophisticated mechanisms for evading assault by the human host. This review focuses on M. tuberculosis regulatory metalloproteins that are sensitive to exogenous stresses attributed to changes in the levels of gaseous molecules (i.e., molecular oxygen, carbon monoxide and nitric oxide) to elicit an intracellular response. In particular, we highlight recent developments on the subfamily of Whi proteins, redox sensing WhiB-like proteins that contain iron-sulfur clusters, sigma factors and their cognate anti-sigma factors of which some are zinc-regulated, and the dormancy survival regulon DosS/DosT-DosR heme sensory system. Mounting experimental evidence suggests that these systems contribute to a highly complex and interrelated regulatory network that controls M. tuberculosis biology. This review concludes with a discussion of strategies that M. tuberculosis has developed to maintain redox homeostasis, including mechanisms to regulate endogenous nitric oxide and carbon monoxide levels.
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Affiliation(s)
- Nicholas Chim
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Parker M Johnson
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA
| | - Celia W Goulding
- Department of Molecular Biology and Biochemistry, UCI, Irvine, CA 92697, USA; Department of Pharmaceutical Sciences, UCI, Irvine, CA 92697, USA.
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8
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Jiang D, Zhang Q, Zheng Q, Zhou H, Jin J, Zhou W, Bartlam M, Rao Z. Structural analysis ofMycobacterium tuberculosisATP-binding cassette transporter subunit UgpB reveals specificity for glycerophosphocholine. FEBS J 2013; 281:331-41. [DOI: 10.1111/febs.12600] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/31/2013] [Accepted: 11/01/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Dunquan Jiang
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Qingqing Zhang
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Qianqian Zheng
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Hao Zhou
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Jin Jin
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Pharmacy; Nankai University; Tianjin China
| | - Weihong Zhou
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Mark Bartlam
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
| | - Zihe Rao
- State Key Laboratory of Medicinal Chemical Biology; Tianjin China
- College of Life Sciences; Nankai University; Tianjin China
- College of Pharmacy; Nankai University; Tianjin China
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