1
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Salaemae W, Thompson AP, Gaiser BI, Lee KJ, Huxley MT, Sumby CJ, Polyak SW, Abell AD, Bruning JB, Wegener KL. Fortuitous In Vitro Compound Degradation Produces a Tractable Hit against Mycobacterium tuberculosis Dethiobiotin Synthetase: A Cautionary Tale of What Goes In Does Not Always Come Out. ACS Chem Biol 2023; 18:1985-1992. [PMID: 37651626 DOI: 10.1021/acschembio.3c00215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
We previously reported potent ligands and inhibitors of Mycobacterium tuberculosis dethiobiotin synthetase (MtDTBS), a promising target for antituberculosis drug development (Schumann et al., ACS Chem Biol. 2021, 16, 2339-2347); here, the unconventional origin of the fragment compound they were derived from is described for the first time. Compound 1 (9b-hydroxy-6b,7,8,9,9a,9b-hexahydrocyclopenta[3,4]cyclobuta[1,2-c]chromen-6(6aH)-one), identified by an in silico fragment screen, was subsequently shown by surface plasmon resonance to have dose-responsive binding (KD = 0.6 mM). Clear electron density was revealed in the DAPA substrate binding pocket when 1 was soaked into MtDTBS crystals, but the density was inconsistent with the structure of 1. Here, we show that the lactone of 1 hydrolyzes to a carboxylic acid (2) under basic conditions, including those of the crystallography soak, with a subsequent ring opening of the component cyclobutane ring forming a cyclopentylacetic acid (3). Crystals soaked directly with authentic 3 produced an electron density that matched that of crystals soaked with presumed 1, confirming the identity of the bound ligand. The synthetic utility of fortuitously formed 3 enabled the subsequent compound development of nanomolar inhibitors. Our findings represent an example of chemical modification within drug discovery assays and demonstrate the value of high-resolution structural data in the fragment hit validation process.
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Affiliation(s)
- Wanisa Salaemae
- Biochemistry, Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Songkhla 90110, Thailand
| | - Andrew P Thompson
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Birgit I Gaiser
- Centre for Nanoscale BioPhotonics (CNBP), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Kwang Jun Lee
- Centre for Nanoscale BioPhotonics (CNBP), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Michael T Huxley
- Department of Chemistry, School of Physics, Chemistry and Earth Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Christopher J Sumby
- Department of Chemistry, School of Physics, Chemistry and Earth Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Steven W Polyak
- Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Andrew D Abell
- Centre for Nanoscale BioPhotonics (CNBP), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
- Department of Chemistry, School of Physics, Chemistry and Earth Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - John B Bruning
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
- Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Kate L Wegener
- Institute of Photonics and Advanced Sensing (IPAS), School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
- Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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2
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Kumar G, C A. Natural products and their analogues acting against Mycobacterium tuberculosis: A recent update. Drug Dev Res 2023; 84:779-804. [PMID: 37086027 DOI: 10.1002/ddr.22063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/28/2023] [Accepted: 04/01/2023] [Indexed: 04/23/2023]
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases caused by Mycobacterium tuberculosis (M.tb). It is responsible for significant causes of mortality and morbidity worldwide. M.tb possesses robust defense mechanisms against most antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. Thus, the efficacy of existing front-line drugs is diminishing, and new and recurring cases of TB arising from multidrug-resistant M.tb are increasing. TB begs the scientific community to explore novel therapeutic avenues. A precise knowledge of the compounds with their mode of action could aid in developing new anti-TB agents that can kill latent and actively multiplying M.tb. This can help in the shortening of the anti-TB regimen and can improve the outcome of treatment strategies. Natural products have contributed several antibiotics for TB treatment. The sources of anti-TB drugs/inhibitors discussed in this work are target-based identification/cell-based and phenotypic screening from natural products. Some of the recently identified natural products derived leads have reached clinical stages of TB drug development, which include rifapentine, CPZEN-45, spectinamide-1599 and 1810. We believe these anti-TB agents could emerge as superior therapeutic compounds to treat TB over known Food and Drug Administration drugs.
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Affiliation(s)
- Gautam Kumar
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Telangana, India
| | - Amrutha C
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Telangana, India
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3
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Xu Y, Yang J, Li W, Song S, Shi Y, Wu L, Sun J, Hou M, Wang J, Jia X, Zhang H, Huang M, Lu T, Gan J, Feng Y. Three enigmatic BioH isoenzymes are programmed in the early stage of mycobacterial biotin synthesis, an attractive anti-TB drug target. PLoS Pathog 2022; 18:e1010615. [PMID: 35816546 PMCID: PMC9302846 DOI: 10.1371/journal.ppat.1010615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/21/2022] [Accepted: 05/24/2022] [Indexed: 11/19/2022] Open
Abstract
Tuberculosis (TB) is one of the leading infectious diseases of global concern, and one quarter of the world’s population are TB carriers. Biotin metabolism appears to be an attractive anti-TB drug target. However, the first-stage of mycobacterial biotin synthesis is fragmentarily understood. Here we report that three evolutionarily-distinct BioH isoenzymes (BioH1 to BioH3) are programmed in biotin synthesis of Mycobacterium smegmatis. Expression of an individual bioH isoform is sufficient to allow the growth of an Escherichia coli ΔbioH mutant on the non-permissive condition lacking biotin. The enzymatic activity in vitro combined with biotin bioassay in vivo reveals that BioH2 and BioH3 are capable of removing methyl moiety from pimeloyl-ACP methyl ester to give pimeloyl-ACP, a cognate precursor for biotin synthesis. In particular, we determine the crystal structure of dimeric BioH3 at 2.27Å, featuring a unique lid domain. Apart from its catalytic triad, we also dissect the substrate recognition of BioH3 by pimeloyl-ACP methyl ester. The removal of triple bioH isoforms (ΔbioH1/2/3) renders M. smegmatis biotin auxotrophic. Along with the newly-identified Tam/BioC, the discovery of three unusual BioH isoforms defines an atypical ‘BioC-BioH(3)’ paradigm for the first-stage of mycobacterial biotin synthesis. This study solves a long-standing puzzle in mycobacterial nutritional immunity, providing an alternative anti-TB drug target.
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Affiliation(s)
- Yongchang Xu
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Jie Yang
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Science, Fudan University, Shanghai, The People’s Republic of China
| | - Weihui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, The People’s Republic of China
| | - Shuaijie Song
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Yu Shi
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Lihan Wu
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Jingdu Sun
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, The People’s Republic of China
| | - Mengyun Hou
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Jinzi Wang
- Guangxi Key Laboratory of Utilization of Microbial and Botanical Resources & Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, Guangxi, The People’s Republic of China
| | - Xu Jia
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, The People’s Republic of China
| | - Huimin Zhang
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Man Huang
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
| | - Ting Lu
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Jianhua Gan
- Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Science, Fudan University, Shanghai, The People’s Republic of China
- * E-mail: (JG); (YF)
| | - Youjun Feng
- Departments of Microbiology, and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, The People’s Republic of China
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, The People’s Republic of China
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, The People’s Republic of China
- * E-mail: (JG); (YF)
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4
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Song J, Chao J, Hu X, Wen X, Ding C, Li D, Zhang D, Han S, Yu X, Yan B, Jin Z, Song Y, Gonzales J, Via LE, Zhang L, Wang D. E3 Ligase FBXW7 Facilitates Mycobacterium Immune Evasion by Modulating TNF-α Expression. Front Cell Infect Microbiol 2022; 12:851197. [PMID: 35651754 PMCID: PMC9149249 DOI: 10.3389/fcimb.2022.851197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/24/2022] [Indexed: 11/26/2022] Open
Abstract
Tumor necrosis factor alpha (TNF-α) is a crucial factor in the control of Mycobacterium tuberculosis (Mtb) infection. Pathogenic mycobacteria can inhibit and/or regulate host cell TNF-α production in a variety of ways to evade antituberculosis (anti-TB) immunity as well as facilitate immune escape. However, the mechanisms by which TNF-α expression in host cells is modulated to the benefit of mycobacteria is still an interesting topic and needs further study. Here, we report that macrophages infected with Mycobacterium marinum (Mm)—a close relative of Mtb—upregulated the expression of E3 ubiquitin ligase FBXW7. Specific silencing FBXW7 with small interfering RNA (siRNA) significantly elevates TNF-α expression and eventually promotes the elimination of intracellular bacteria. In turn, overexpression of FBXW7 in Raw264.7 macrophages markedly decreased TNF-α production. Furthermore, partial inhibition of FBXW7 in an Mm-infected murine model significantly reduced TNF-α tissue content, alleviated tissue damage as well as reduced the bacterial load of mouse tails. Finally, FBXW7 could decrease TNF-α in a K63-linked ubiquitin signaling dependent manner. Taken together, our study uncovered a previously unknown role of FBXW7 in regulating TNF-α dynamics during mycobacterial infection, which provides new insights into understanding the role of FBXW7 in anti-tuberculosis immunity and its related clinical significance.
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Affiliation(s)
- Jingrui Song
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Jin Chao
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Xiaohong Hu
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Department of Tuberculosis, The Third People’s Hospital of Yichang, Yichang, China
| | - Xin Wen
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Cairong Ding
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Dan Li
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Department of Tuberculosis, The Third People’s Hospital of Yichang, Yichang, China
| | - Ding Zhang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
- Department of Pathology, Yichang Central People’s Hospital, Yichang, China
| | - Shanshan Han
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Xiang Yu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Bo Yan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Zhu Jin
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Department of Tuberculosis, The Third People’s Hospital of Yichang, Yichang, China
| | - Yinhong Song
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
| | - Jacqueline Gonzales
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, and Tuberculosis Imaging Program, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Laura E. Via
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, and Tuberculosis Imaging Program, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Lu Zhang
- Engineering Research Center of Gene Technology, Ministry of Education, Department of Microbiology, School of Life Science, Fudan University, Shanghai, China
- *Correspondence: Lu Zhang, ; Decheng Wang,
| | - Decheng Wang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang, China
- Institute of Infection and Inflammation, China Three Gorges University, Yichang, China
- Medical College, China Three Gorges University, Yichang, China
- *Correspondence: Lu Zhang, ; Decheng Wang,
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5
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Ackland J, Heinson AI, Cleary DW, Christodoulides M, Wilkinson TMA, Staples KJ. Dual RNASeq Reveals NTHi-Macrophage Transcriptomic Changes During Intracellular Persistence. Front Cell Infect Microbiol 2021; 11:723481. [PMID: 34497778 PMCID: PMC8419319 DOI: 10.3389/fcimb.2021.723481] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/26/2021] [Indexed: 12/13/2022] Open
Abstract
Nontypeable Haemophilus influenzae (NTHi) is a pathobiont which chronically colonises the airway of individuals with chronic respiratory disease and is associated with poor clinical outcomes. It is unclear how NTHi persists in the airway, however accumulating evidence suggests that NTHi can invade and persist within macrophages. To better understand the mechanisms of NTHi persistence within macrophages, we developed an in vitro model of NTHi intracellular persistence using human monocyte-derived macrophages (MDM). Dual RNA Sequencing was used to assess MDM and NTHi transcriptomic regulation occurring simultaneously during NTHi persistence. Analysis of the macrophage response to NTHi identified temporally regulated transcriptomic profiles, with a specific 'core' profile displaying conserved expression of genes across time points. Gene list enrichment analysis identified enrichment of immune responses in the core gene set, with KEGG pathway analysis revealing specific enrichment of intracellular immune response pathways. NTHi persistence was facilitated by modulation of bacterial metabolic, stress response and ribosome pathways. Levels of NTHi genes bioC, mepM and dps were differentially expressed by intracellular NTHi compared to planktonic NTHi, indicating that the transcriptomic adaption was distinct between the two different NTHi lifestyles. Overall, this study provides crucial insights into the transcriptomic adaptations facilitating NTHi persistence within macrophages. Targeting these reported pathways with novel therapeutics to reduce NTHi burden in the airway could be an effective treatment strategy given the current antimicrobial resistance crisis and lack of NTHi vaccines.
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Affiliation(s)
- Jodie Ackland
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Ashley I Heinson
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - David W Cleary
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Myron Christodoulides
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Tom M A Wilkinson
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Wessex Investigational Sciences Hub, Southampton General Hospital, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Karl J Staples
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Wessex Investigational Sciences Hub, Southampton General Hospital, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
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6
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Bockman MR, Mishra N, Aldrich CC. The Biotin Biosynthetic Pathway in Mycobacterium tuberculosis is a Validated Target for the Development of Antibacterial Agents. Curr Med Chem 2020; 27:4194-4232. [PMID: 30663561 DOI: 10.2174/0929867326666190119161551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/14/2018] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis, responsible for Tuberculosis (TB), remains the leading cause of mortality among infectious diseases worldwide from a single infectious agent, with an estimated 1.7 million deaths in 2016. Biotin is an essential cofactor in M. tuberculosis that is required for lipid biosynthesis and gluconeogenesis. M. tuberculosis relies on de novo biotin biosynthesis to obtain this vital cofactor since it cannot scavenge sufficient biotin from a mammalian host. The biotin biosynthetic pathway in M. tuberculosis has been well studied and rigorously genetically validated providing a solid foundation for medicinal chemistry efforts. This review examines the mechanism and structure of the enzymes involved in biotin biosynthesis and ligation, summarizes the reported genetic validation studies of the pathway, and then analyzes the most promising inhibitors and natural products obtained from structure-based drug design and phenotypic screening.
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Affiliation(s)
- Matthew R Bockman
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Neeraj Mishra
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, United States
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7
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Sprenger M, Hartung TS, Allert S, Wisgott S, Niemiec MJ, Graf K, Jacobsen ID, Kasper L, Hube B. Fungal biotin homeostasis is essential for immune evasion after macrophage phagocytosis and virulence. Cell Microbiol 2020; 22:e13197. [PMID: 32083801 DOI: 10.1111/cmi.13197] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 01/05/2023]
Abstract
Biotin is an important cofactor for multiple enzymes in central metabolic processes. While many bacteria and most fungi are able to synthesise biotin de novo, Candida spp. are auxotrophic for this vitamin and thus require efficient uptake systems to facilitate biotin acquisition during infection. Here we show that Candida glabrata and Candida albicans use a largely conserved system for biotin uptake and regulation, consisting of the high-affinity biotin transporter Vht1 and the transcription factor Vhr1. Both species induce expression of biotin-metabolic genes upon in vitro biotin depletion and following phagocytosis by macrophages, indicating low biotin levels in the Candida-containing phagosome. In line with this, we observed reduced intracellular proliferation of both Candida cells pre-starved of biotin and deletion mutants lacking VHR1 or VHT1 genes. VHT1 was essential for the full virulence of C. albicans during systemic mouse infections, and the lack of VHT1 led to reduced fungal burden in C. glabrata-infected brains and C. albicans-infected brains and kidneys. Together, our data suggest a critical role of Vht1-mediated biotin acquisition for C. glabrata and C. albicans during intracellular growth in macrophages and systemic infections.
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Affiliation(s)
- Marcel Sprenger
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Teresa S Hartung
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Stefanie Allert
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Stephanie Wisgott
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Maria J Niemiec
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - Katja Graf
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Ilse D Jacobsen
- Research Group Microbial Immunology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany.,Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knoell Institute, Jena, Germany.,Institute of Microbiology, Friedrich Schiller University, Jena, Germany
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8
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Ren X, Wang X, Shi H, Zhang X, Chen Z, Malhi KK, Ding C, Yu S. Riemerella anatipestifer AS87_RS09170 gene is responsible for biotin synthesis, bacterial morphology and virulence. Sci Rep 2018; 8:14645. [PMID: 30279476 PMCID: PMC6168606 DOI: 10.1038/s41598-018-32905-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 09/18/2018] [Indexed: 11/12/2022] Open
Abstract
Riemerella anatipestifer is a bacterial pathogen responsible for major economic losses within the duck industry. Recent studies have revealed that biotin biosynthesis is critical for the bacterium’s survival and virulence. We previously found that R. anatipestifer AS87_RS09170, a putative bioF gene, is important for bacterial virulence. In the present study, we characterized the AS87_RS09170 gene in R. anatipestifer strain Yb2. Sequence analysis indicated that the AS87_RS09170 gene is highly conserved among R. anatipestifer strains; the deduced protein harbored the conserved pyridoxal 5′-phosphate binding pocket of 8-amino-7-oxononanoate synthase. Western blot analysis demonstrated that the biotin-dependent enzyme was present in smaller quantities in the mutant strain Yb2ΔbioF compared to that of the wide-type strain Yb2, suggesting that the biotin biosynthesis was defective. The mutant strain Yb2ΔbioF displayed a decreased growth rate at the exponential phase in tryptic soy broth culture and in BeaverBeads Streptavidin treated tryptic soy broth culture, but recovered when biotin was supplemented. In addition, the mutant strain Yb2ΔbioF showed an enhanced biofilm formation, as well as increased adhesion and invasion capacities to duck embryo fibroblasts. Moreover, the mutant strain Yb2ΔbioF exhibited irregular shapes with budding vegetations and relatively thickened cell walls under scanning and transmission electron microscope observation, as well as a reduced capacity to establish systemic infection in a duck infection model. These results provide the first evidence that the R. anatipestifer AS87_RS09170 gene is responsible for biotin synthesis, bacterial morphology and virulence.
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Affiliation(s)
- Xiaomei Ren
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaolan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Huoying Shi
- College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xuemei Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Zongchao Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Kanwar Kumar Malhi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou, Jiangsu, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China. .,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou, Jiangsu, China.
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9
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Sprenger M, Kasper L, Hensel M, Hube B. Metabolic adaptation of intracellular bacteria and fungi to macrophages. Int J Med Microbiol 2017; 308:215-227. [PMID: 29150190 DOI: 10.1016/j.ijmm.2017.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/21/2017] [Accepted: 11/05/2017] [Indexed: 02/07/2023] Open
Abstract
The mature phagosome of macrophages is a hostile environment for the vast majority of phagocytosed microbes. In addition to active destruction of the engulfed microbes by antimicrobial compounds, restriction of essential nutrients in the phagosomal compartment contributes to microbial growth inhibition and killing. However, some pathogenic microorganisms have not only developed various strategies to efficiently withstand or counteract antimicrobial activities, but also to acquire nutrients within macrophages for intracellular replication. Successful intracellular pathogens are able to utilize host-derived amino acids, carbohydrates and lipids as well as trace metals and vitamins during intracellular growth. This requires sophisticated strategies such as phagosome modification or escape, efficient nutrient transporters and metabolic adaptation. In this review, we discuss the metabolic adaptation of facultative intracellular bacteria and fungi to the intracellular lifestyle inside macrophages.
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Affiliation(s)
- Marcel Sprenger
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Lydia Kasper
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Michael Hensel
- Division of Microbiology, University Osnabrück, Osnabrück, Germany
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany; Friedrich Schiller University, Jena, Germany; Center for Sepsis Control and Care, University Hospital, Jena, Germany.
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10
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Kar R, Nangpal P, Mathur S, Singh S, Tyagi AK. bioA mutant of Mycobacterium tuberculosis shows severe growth defect and imparts protection against tuberculosis in guinea pigs. PLoS One 2017; 12:e0179513. [PMID: 28658275 PMCID: PMC5489182 DOI: 10.1371/journal.pone.0179513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/30/2017] [Indexed: 01/03/2023] Open
Abstract
Owing to the devastation caused by tuberculosis along with the unsatisfactory performance of the Bacillus Calmette–Guérin (BCG) vaccine, a more efficient vaccine than BCG is required for the global control of tuberculosis. A number of studies have demonstrated an essential role of biotin biosynthesis in the growth and survival of several microorganisms, including mycobacteria, through deletion of the genes involved in de novo biotin biosynthesis. In this study, we demonstrate that a bioA mutant of Mycobacterium tuberculosis (MtbΔbioA) is highly attenuated in the guinea pig model of tuberculosis when administered aerogenically as well as intradermally. Immunization with MtbΔbioA conferred significant protection in guinea pigs against an aerosol challenge with virulent M. tuberculosis, when compared with the unvaccinated animals. Booster immunization with MtbΔbioA offered no advantage over a single immunization. These experiments demonstrate the vaccinogenic potential of the attenuated M. tuberculosis bioA mutant against tuberculosis.
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Affiliation(s)
- Ritika Kar
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Prachi Nangpal
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Shubhita Mathur
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Swati Singh
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
| | - Anil K. Tyagi
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi, India
- Vice Chancellor, Guru Gobind Singh Indraprastha University, Dwarka, New Delhi, India
- * E-mail:
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11
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Shi J, Cao X, Chen Y, Cronan JE, Guo Z. An Atypical α/β-Hydrolase Fold Revealed in the Crystal Structure of Pimeloyl-Acyl Carrier Protein Methyl Esterase BioG from Haemophilus influenzae. Biochemistry 2016; 55:6705-6717. [PMID: 27933801 DOI: 10.1021/acs.biochem.6b00818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pimeloyl-acyl carrier protein (ACP) methyl esterase is an α/β-hydrolase that catalyzes the last biosynthetic step of pimeloyl-ACP, a key intermediate in biotin biosynthesis. Intriguingly, multiple nonhomologous isofunctional forms of this enzyme that lack significant sequence identity are present in diverse bacteria. One such esterase, Escherichia coli BioH, has been shown to be a typical α/β-hydrolase fold enzyme. To gain further insights into the role of this step in biotin biosynthesis, we have determined the crystal structure of another widely distributed pimeloyl-ACP methyl esterase, Haemophilus influenzae BioG, at 1.26 Å. The BioG structure is similar to the BioH structure and is composed of an α-helical lid domain and a core domain that contains a central seven-stranded β-pleated sheet. However, four of the six α-helices that flank both sides of the BioH core β-sheet are replaced with long loops in BioG, thus forming an unusual α/β-hydrolase fold. This structural variation results in a significantly decreased thermal stability of the enzyme. Nevertheless, the lid domain and the residues at the lid-core interface are well conserved between BioH and BioG, in which an analogous hydrophobic pocket for pimelate binding as well as similar ionic interactions with the ACP moiety are retained. Biochemical characterization of site-directed mutants of the residues hypothesized to interact with the ACP moiety supports a similar substrate interaction mode for the two enzymes. Consequently, these enzymes package the identical catalytic function under a considerably different protein surface.
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Affiliation(s)
- Jie Shi
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
| | | | - Yaozong Chen
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
| | | | - Zhihong Guo
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
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12
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Huang X, Wang H, Meng L, Wang Q, Yu J, Gao Q, Wang D. Role of eosinophils and apoptosis in PDIMs/PGLs deficient mycobacterium elimination in adult zebrafish. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2016; 59:199-206. [PMID: 26855012 DOI: 10.1016/j.dci.2016.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/03/2016] [Accepted: 02/03/2016] [Indexed: 06/05/2023]
Abstract
The cell wall lipids phthiocerol dimycocerosates (PDIMs) and its structurally-related compound, phenolic glycolipids (PGLs) are major virulence factors of mycobacterium, as shown by the reduced growth of PDIMs/PGLs deficient mutants in various animal models. PDIMs/PGLs play active roles in modulating host immune responses. However, the cellular and molecular mechanisms of how PDIMs/PGLs deficient mutant was eliminated in vivo are still elusive. Our aim was to investigate what host immune responses have effect on mycobacterium elimination in vivo. Using microarray, we find PDIMs/PGLs modulate divergent host responses, including chemotaxis and focal adhesion's downstream pathway and apoptosis. We examine these two host responses by Diff-Quik stain, coupled with transmission electron microscopy and TUNEL stain respectively. The ultrastructure observation showed that eosinophils appeared in WT-infected zebrafish at day 1, however eosinophils arrived was delayed to day 7 in PDIMs/PGLs-deficient mutant-infected animals. More intriguingly, apoptosis was markedly increased in PDIMs/PGLs-mutant infected zebrafish at day 1 after infection, compared to WT-infected fishes at this time. However, apoptosis trend was fully reversed by day 7, with increased apoptosis were detected in WT-infected zebrafish compared with the PDIMs/PGLs-deficient mutant, especially more apoptosis within the granuloma. This study shows that the anti-apoptotic effects of PDIMs/PGLs and the recruitment of eosinophils in tissue during the early infection in zebrafish might promote bacterium growth in vivo.
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Affiliation(s)
- Xinhua Huang
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Hui Wang
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Lu Meng
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Qinglan Wang
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Jia Yu
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Qian Gao
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China
| | - Decheng Wang
- Key Laboratory of Medical Molecular Virology, Institutes of Biomedical Sciences and Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai, 200032 PR China; Medical College of China Three Gorges University, Hubei, 443002 PR China.
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13
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The Role of Biotin in Bacterial Physiology and Virulence: a Novel Antibiotic Target for
Mycobacterium tuberculosis. Microbiol Spectr 2016; 4. [DOI: 10.1128/microbiolspec.vmbf-0008-2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
Biotin is an essential cofactor for enzymes present in key metabolic pathways such as fatty acid biosynthesis, replenishment of the tricarboxylic acid cycle, and amino acid metabolism. Biotin is synthesized
de novo
in microorganisms, plants, and fungi, but this metabolic activity is absent in mammals, making biotin biosynthesis an attractive target for antibiotic discovery. In particular, biotin biosynthesis plays important metabolic roles as the sole source of biotin in all stages of the
Mycobacterium tuberculosis
life cycle due to the lack of a transporter for scavenging exogenous biotin. Biotin is intimately associated with lipid synthesis where the products form key components of the mycobacterial cell membrane that are critical for bacterial survival and pathogenesis. In this review we discuss the central role of biotin in bacterial physiology and highlight studies that demonstrate the importance of its biosynthesis for virulence. The structural biology of the known biotin synthetic enzymes is described alongside studies using structure-guided design, phenotypic screening, and fragment-based approaches to drug discovery as routes to new antituberculosis agents.
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14
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Whole-Genome Sequence Analysis and Genome-Wide Virulence Gene Identification of Riemerella anatipestifer Strain Yb2. Appl Environ Microbiol 2015; 81:5093-102. [PMID: 26002892 DOI: 10.1128/aem.00828-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/13/2015] [Indexed: 01/06/2023] Open
Abstract
Riemerella anatipestifer is a well-described pathogen of waterfowl and other avian species that can cause septicemic and exudative diseases. In this study, we sequenced the complete genome of R. anatipestifer strain Yb2 and analyzed it against the published genomic sequences of R. anatipestifer strains DSM15868, RA-GD, RA-CH-1, and RA-CH-2. The Yb2 genome contains one circular chromosome of 2,184,066 bp with a 35.73% GC content and no plasmid. The genome has 2,021 open reading frames that occupy 90.88% of the genome. A comparative genomic analysis revealed that genome organization is highly conserved among R. anatipestifer strains, except for four inversions of a sequence segment in Yb2. A phylogenetic analysis found that the closest neighbor of Yb2 is RA-GD. Furthermore, we constructed a library of 3,175 mutants by random transposon mutagenesis, and 100 mutants exhibiting more than 100-fold-attenuated virulence were obtained by animal screening experiments. Southern blot analysis and genetic characterization of the mutants led to the identification of 49 virulence genes. Of these, 25 encode cytoplasmic proteins, 6 encode cytoplasmic membrane proteins, 4 encode outer membrane proteins, and the subcellular localization of the remaining 14 gene products is unknown. The functional classification of orthologous-group clusters revealed that 16 genes are associated with metabolism, 6 are associated with cellular processing and signaling, and 4 are associated with information storage and processing. The functions of the other 23 genes are poorly characterized or unknown. This genome-wide study identified genes important to the virulence of R. anatipestifer.
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15
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CpsA, a LytR-CpsA-Psr Family Protein in Mycobacterium marinum, Is Required for Cell Wall Integrity and Virulence. Infect Immun 2015; 83:2844-54. [PMID: 25939506 DOI: 10.1128/iai.03081-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/20/2015] [Indexed: 12/28/2022] Open
Abstract
LytR-CpsA-Psr family proteins play an important role in bacterial cell wall integrity. Although the pathogenic relevance of LytR-CpsA-Psr family proteins has been studied in a few bacterial pathogens, their function in mycobacteria remains uncharacterized. In this work, a transposon insertion mutant (cpsA::Tn) of Mycobacterium marinum was studied. We found that inactivation of CpsA altered bacterial colony morphology, sliding motility, cell surface hydrophobicity, and cell wall permeability. Besides, the cpsA mutant exhibited a decreased arabinogalactan content, indicating that CpsA plays a role in cell wall assembly. Moreover, the mutant shows impaired growth within macrophage cell lines and is severely attenuated in zebrafish larvae and adult zebrafish. Taken together, our results indicated that CpsA, a previously uncharacterized protein, is important for mycobacterial cell wall integrity and is required for mycobacterial virulence.
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16
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Salaemae W, Yap MY, Wegener KL, Booker GW, Wilce MCJ, Polyak SW. Nucleotide triphosphate promiscuity in Mycobacterium tuberculosis dethiobiotin synthetase. Tuberculosis (Edinb) 2015; 95:259-66. [PMID: 25801336 DOI: 10.1016/j.tube.2015.02.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/26/2015] [Indexed: 11/29/2022]
Abstract
Dethiobiotin synthetase (DTBS) plays a crucial role in biotin biosynthesis in microorganisms, fungi, and plants. Due to its importance in bacterial pathogenesis, and the absence of a human homologue, DTBS is a promising target for the development of new antibacterials desperately needed to combat antibiotic resistance. Here we report the first X-ray structure of DTBS from Mycobacterium tuberculosis (MtDTBS) bound to a nucleotide triphosphate (CTP). The nucleoside base is stabilized in its pocket through hydrogen-bonding interactions with the protein backbone, rather than amino acid side chains. This resulted in the unexpected finding that MtDTBS could utilise ATP, CTP, GTP, ITP, TTP, or UTP with similar Km and kcat values, although the enzyme had the highest affinity for CTP in competitive binding and surface plasmon resonance assays. This is in contrast to other DTBS homologues that preferentially bind ATP primarily through hydrogen-bonds between the purine base and the carboxamide side chain of a key asparagine. Mutational analysis performed alongside in silico experiments revealed a gate-keeper role for Asn175 in Escherichia coli DTBS that excludes binding of other nucleotide triphosphates. Here we provide evidence to show that MtDTBS has a broad nucleotide specificity due to the absence of the gate-keeper residue.
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Affiliation(s)
- Wanisa Salaemae
- School of Biological Sciences, The University of Adelaide, South Australia, 5005, Australia
| | - Min Y Yap
- Department of Biochemistry and Molecular Biology, School of Biomedical Science, Monash University, Victoria, 3800, Australia
| | - Kate L Wegener
- School of Biological Sciences, The University of Adelaide, South Australia, 5005, Australia
| | - Grant W Booker
- School of Biological Sciences, The University of Adelaide, South Australia, 5005, Australia
| | - Matthew C J Wilce
- Department of Biochemistry and Molecular Biology, School of Biomedical Science, Monash University, Victoria, 3800, Australia
| | - Steven W Polyak
- School of Biological Sciences, The University of Adelaide, South Australia, 5005, Australia.
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17
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Structure and function of Mycobacterium smegmatis 7-keto-8-aminopelargonic acid (KAPA) synthase. Int J Biochem Cell Biol 2014; 58:71-80. [PMID: 25462832 DOI: 10.1016/j.biocel.2014.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 10/24/2014] [Accepted: 11/10/2014] [Indexed: 12/30/2022]
Abstract
The biotin biosynthesis pathway is an attractive target for development of novel drugs against mycobacterial pathogens, however there are as yet no suitable inhibitors that target this pathway in mycobacteria. 7-Keto-8-aminopelargonic acid synthase (KAPA synthase, BioF) is the enzyme which catalyzes the first committed step of the biotin synthesis pathway, but both its structure and function in mycobacteria remain unresolved. Here we present the crystal structure of Mycobacterium smegmatis BioF (MsBioF). The structure reveals an incomplete dimer, and the active site organization is similar to, but distinct from Escherichia coli 8-amino-7-oxononanoate synthase (EcAONS), the E. coli homologue of BioF. To investigate the influence of structural characteristics on the function of MsBioF, we deleted bioF in M. smegmatis and confirmed that BioF is required for growth in the absence of exogenous biotin. Based on structural and mutagenesis studies, we confirmed that pyridoxal 5'-phosphate (PLP) binding site residues His129, Lys235 and His200 are essential for MsBioF activity in vivo and residue Glu171 plays an important, but not essential role in MsBioF activity. The N-terminus (residues 1-37) is also essential for MsBioF activity in vivo. The structure and function of MsBioF reported here provides further insights for developing new anti-tuberculosis inhibitors aimed at the biotin synthesis pathway.
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18
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Garfoot AL, Zemska O, Rappleye CA. Histoplasma capsulatum depends on de novo vitamin biosynthesis for intraphagosomal proliferation. Infect Immun 2014; 82:393-404. [PMID: 24191299 PMCID: PMC3911860 DOI: 10.1128/iai.00824-13] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 10/29/2013] [Indexed: 01/07/2023] Open
Abstract
During infection of the mammalian host, Histoplasma capsulatum yeasts survive and reside within macrophages of the immune system. Whereas some intracellular pathogens escape into the host cytosol, Histoplasma yeasts remain within the macrophage phagosome. This intracellular Histoplasma-containing compartment imposes nutritional challenges for yeast growth and replication. We identified and annotated vitamin synthesis pathways encoded in the Histoplasma genome and confirmed by growth in minimal medium that Histoplasma yeasts can synthesize all essential vitamins with the exception of thiamine. Riboflavin, pantothenate, and biotin auxotrophs of Histoplasma were generated to probe whether these vitamins are available to intracellular yeasts. Disruption of the RIB2 gene (riboflavin biosynthesis) prevented growth and proliferation of yeasts in macrophages and severely attenuated Histoplasma virulence in a murine model of respiratory histoplasmosis. Rib2-deficient yeasts were not cleared from lung tissue but persisted, consistent with functional survival mechanisms but inability to replicate in vivo. In addition, depletion of Pan6 (pantothenate biosynthesis) but not Bio2 function (biotin synthesis) also impaired Histoplasma virulence. These results indicate that the Histoplasma-containing phagosome is limiting for riboflavin and pantothenate and that Histoplasma virulence requires de novo synthesis of these cofactor precursors. Since mammalian hosts do not rely on vitamin synthesis but instead acquire essential vitamins through diet, vitamin synthesis pathways represent druggable targets for therapeutics.
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Affiliation(s)
- Andrew L Garfoot
- Department of Microbiology, Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
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19
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Mann S, Eveleigh L, Lequin O, Ploux O. A microplate fluorescence assay for DAPA aminotransferase by detection of the vicinal diamine 7,8-diaminopelargonic acid. Anal Biochem 2013; 432:90-6. [DOI: 10.1016/j.ab.2012.09.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/26/2012] [Accepted: 09/29/2012] [Indexed: 10/27/2022]
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20
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PhoY2 of mycobacteria is required for metabolic homeostasis and stress response. J Bacteriol 2012; 195:243-52. [PMID: 23123909 DOI: 10.1128/jb.01556-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The ability of pathogenic mycobacteria to adapt to diverse environments is essential for their success as pathogens. Here we describe a transposon-inactivated phoY2 mutant of Mycobacterium marinum. PhoY2 of mycobacteria is a functional homologue of PhoU in Escherichia coli and an important component of the Pho regulon. We found that PhoY2 is required for maintaining intracellular inorganic phosphate (P(i)) homeostasis and balanced energy and redox states. Disruption of phoY2 resulted in elevated levels of intracellular poly-P(i) and ATP and an elevated NAD(+)/NADH ratio, and the mutant strain exhibited increased sensitivity to environmental stress conditions, including nutrient deprivation as well as SDS and antibiotic treatments. Taken together, our results suggest that PhoY2 is required for maintaining metabolic homeostasis and adaptation to stress conditions, which may provide an explanation for the suggested role of PhoY2 in drug tolerance.
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21
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Wang D, Zhou W, Lu S, Wang Q, Feng Y, Zhu G, Li L, Song Y, Gao Q. Increased density of macrophage migration inhibitory factor (MIF) in tuberculosis granuloma. Exp Mol Pathol 2012; 93:207-12. [DOI: 10.1016/j.yexmp.2012.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 05/01/2012] [Accepted: 05/02/2012] [Indexed: 11/30/2022]
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22
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Both phthiocerol dimycocerosates and phenolic glycolipids are required for virulence of Mycobacterium marinum. Infect Immun 2012; 80:1381-9. [PMID: 22290144 DOI: 10.1128/iai.06370-11] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Phthiocerol dimycocerosates (PDIMs) and structurally related phenolic glycolipids (PGLs) are complex cell wall lipids unique to pathogenic mycobacteria. While these lipids have been extensively studied in recent years, there are conflicting reports on some aspects of their biosynthesis and on the role of PDIMs and especially PGLs in virulence of Mycobacterium tuberculosis. This has been complicated by the natural deficiency of PGLs in many clinical strains of M. tuberculosis and the frequent loss of PDIMs in laboratory M. tuberculosis strains. In this study, we isolated seven mutants of Mycobacterium marinum deficient in PDIMs and/or PGLs in which multiple genes of the PDIM/PGL biosynthetic locus were disrupted by transposon insertion. Zebrafish infection experiments showed that M. marinum strains lacking one or both of these lipids were avirulent, suggesting that both PDIMs and PGLs are required for virulence. We also found that these strains were hypersensitive to antibiotics and exhibited increased cell wall permeability. Our studies provide new insights into the biosynthesis of PDIMs/PGLs and may help us to understand the role of PDIMs and PGLs in M. tuberculosis virulence.
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23
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Salaemae W, Azhar A, Booker GW, Polyak SW. Biotin biosynthesis in Mycobacterium tuberculosis: physiology, biochemistry and molecular intervention. Protein Cell 2012; 2:691-5. [PMID: 21976058 DOI: 10.1007/s13238-011-1100-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Biotin is an important micronutrient that serves as an essential enzyme cofactor. Bacteria obtain biotin either through de novo synthesis or by active uptake from exogenous sources. Mycobacteria are unusual amongst bacteria in that their primary source of biotin is through de novo synthesis. Here we review the importance of biotin biosynthesis in the lifecycle of Mycobacteria. Genetic screens designed to identify key metabolic processes have highlighted a role for the biotin biosynthesis in bacilli growth, infection and survival during the latency phase. These studies help to establish the biotin biosynthetic pathway as a potential drug target for new anti-tuberculosis agents.
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Affiliation(s)
- Wanisa Salaemae
- School of Molecular and Biomedical Sciences, University of Adelaide, South Australia 5005, Australia
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24
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PPE38 modulates the innate immune response and is required for Mycobacterium marinum virulence. Infect Immun 2011; 80:43-54. [PMID: 22038915 DOI: 10.1128/iai.05249-11] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) family proteins are prevalent in pathogenic mycobacteria and play a diverse role in mycobacterial pathogenesis. While some members have been studied, the function of most PE/PPE proteins remains unknown. In this study, we isolated a transposon-inactivated PPE38 mutant of Mycobacterium marinum and characterized its phenotype. We found that the PPE38 protein is associated with the cell wall and exposed on the cell surface. The inactivation of PPE38 altered the bacterial cell surface properties and led to deficiencies in cord formation, sliding motility, and biofilm formation. The PPE38 mutant was defective in phagocytosis by macrophages and exhibited reduced virulence in adult zebrafish. We also found that PPE38 is involved in the induction of proinflammatory cytokines in infected macrophages. Together, our results indicate that PPE38, a previously uncharacterized protein, plays a role in mycobacterial virulence, presumably by modulating the host innate immune response.
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25
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Woong Park S, Klotzsche M, Wilson DJ, Boshoff HI, Eoh H, Manjunatha U, Blumenthal A, Rhee K, Barry CE, Aldrich CC, Ehrt S, Schnappinger D. Evaluating the sensitivity of Mycobacterium tuberculosis to biotin deprivation using regulated gene expression. PLoS Pathog 2011; 7:e1002264. [PMID: 21980288 PMCID: PMC3182931 DOI: 10.1371/journal.ppat.1002264] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Accepted: 07/28/2011] [Indexed: 12/04/2022] Open
Abstract
In the search for new drug targets, we evaluated the biotin synthetic pathway of Mycobacterium tuberculosis (Mtb) and constructed an Mtb mutant lacking the biotin biosynthetic enzyme 7,8-diaminopelargonic acid synthase, BioA. In biotin-free synthetic media, ΔbioA did not produce wild-type levels of biotinylated proteins, and therefore did not grow and lost viability. ΔbioA was also unable to establish infection in mice. Conditionally-regulated knockdown strains of Mtb similarly exhibited impaired bacterial growth and viability in vitro and in mice, irrespective of the timing of transcriptional silencing. Biochemical studies further showed that BioA activity has to be reduced by approximately 99% to prevent growth. These studies thus establish that de novo biotin synthesis is essential for Mtb to establish and maintain a chronic infection in a murine model of TB. Moreover, these studies provide an experimental strategy to systematically rank the in vivo value of potential drug targets in Mtb and other pathogens. We evaluated the biotin synthetic pathway of Mycobacterium tuberculosis (Mtb) as a new drug target by first generating an Mtb deletion mutant, ΔbioA, in which the biotin biosynthetic enzyme 7,8-diaminopelargonic acid synthase (BioA) has been inactivated. This mutant grew in the presence of biotin or des-thiobiotin, but not with an intermediate of the biotin biosynthesis pathway that requires BioA to be converted into biotin. Without exogenous biotin or des-thiobiotin, ΔbioA, was unable to produce biotinylated proteins, which are required for the biosynthesis of fatty acids, and thus died in biotin-free media. Using a regulatable promoter and different ribosome binding sequences we next constructed tightly controlled TetON mutants, in which expression of BioA could be induced with tetracyclines, but was inhibited in their absence. Characterization of these mutants during infections demonstrated that de novo biotin synthesis is not only required to establish infections but also to maintain bacterial persistence. Inhibition of BioA or other enzymes of the biotin biosynthesis pathways could thus be used to kill Mtb during both acute and chronic infections. Biochemical and immunological analyses of different Mtb mutants indicate that drugs targeting BioA would have to inactive approximately 99% of its activity to be effective.
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Affiliation(s)
- Sae Woong Park
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Marcus Klotzsche
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Daniel J. Wilson
- Center for Drug Design, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Helena I. Boshoff
- Tuberculosis Research Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Hyungjin Eoh
- Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | | | - Antje Blumenthal
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Kyu Rhee
- Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Clifton E. Barry
- Tuberculosis Research Section, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland, United States of America
| | - Courtney C. Aldrich
- Center for Drug Design, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (SE); (DS)
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail: (SE); (DS)
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