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Agarwal M, Bhaskar A, Singha B, Mukhopadhyay S, Pahuja I, Singh A, Chaturvedi S, Agarwal N, Dwivedi VP, Nandicoori VK. Depletion of essential mycobacterial gene glmM reduces pathogen survival and induces host-protective immune responses against tuberculosis. Commun Biol 2024; 7:949. [PMID: 39107377 PMCID: PMC11303689 DOI: 10.1038/s42003-024-06620-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 07/23/2024] [Indexed: 08/10/2024] Open
Abstract
The limitations of TB treatment are the long duration and immune-dampening effects of anti-tuberculosis therapy. The Cell wall plays a crucial role in survival and virulence; hence, enzymes involved in its biosynthesis are good therapeutic targets. Here, we identify Mycobacterium tuberculosis (Mtb) GlmM, (GlmMMtb) engaged in the UDP-GlcNAc synthesis pathway as an essential enzyme. We generated a conditional knockdown strain, Rv-glmMkD using the CRISPR interference-mediated gene silencing approach. Depletion of GlmMMtb affects the morphology and thickness of the cell wall. The Rv-glmMkD strain attenuated Mtb survival in vitro, in the host macrophages (ex vivo), and in a murine mice infection model (in vivo). Results suggest that the depletion of GlmMMtb induces M1 macrophage polarization, prompting a pro-inflammatory cytokine response, apparent from the upregulation of activation markers, including IFNɣ and IL-17 that resists the growth of Mtb. These observations provide a rationale for exploring GlmMMtb as a potential therapeutic target.
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Affiliation(s)
- Meetu Agarwal
- Signal Transduction Laboratory, National Institute of Immunology, New Delhi, India.
- Department of Molecular Medicine, Jamia Hamdard University, New Delhi, India.
| | - Ashima Bhaskar
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Biplab Singha
- Signal Transduction Laboratory, National Institute of Immunology, New Delhi, India
| | - Suparba Mukhopadhyay
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Isha Pahuja
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Archna Singh
- CSIR - Institute of Genomics and Integrative Biology, Mall Road, Delhi, India
| | - Shivam Chaturvedi
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Nisheeth Agarwal
- Translational Health Science and Technology Institute (THSTI), Faridabad, India
| | - Ved Prakash Dwivedi
- Immunobiology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Vinay Kumar Nandicoori
- Signal Transduction Laboratory, National Institute of Immunology, New Delhi, India.
- CSIR-Centre for Cellular and Molecular Biology, Habsiguda, Hyderabad, Telangana, India.
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2
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Soni V, Rosenn EH, Venkataraman R. Insights into the central role of N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmU) in peptidoglycan metabolism and its potential as a therapeutic target. Biochem J 2023; 480:1147-1164. [PMID: 37498748 DOI: 10.1042/bcj20230173] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
Several decades after the discovery of the first antibiotic (penicillin) microbes have evolved novel mechanisms of resistance; endangering not only our abilities to combat future bacterial pandemics but many other clinical challenges such as acquired infections during surgeries. Antimicrobial resistance (AMR) is attributed to the mismanagement and overuse of these medications and is complicated by a slower rate of the discovery of novel drugs and targets. Bacterial peptidoglycan (PG), a three-dimensional mesh of glycan units, is the foundation of the cell wall that protects bacteria against environmental insults. A significant percentage of drugs target PG, however, these have been rendered ineffective due to growing drug resistance. Identifying novel druggable targets is, therefore, imperative. Uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) is one of the key building blocks in PG production, biosynthesized by the bifunctional enzyme N-acetyl-glucosamine-1-phosphate uridyltransferase (GlmU). UDP-GlcNAc metabolism has been studied in many organisms, but it holds some distinctive features in bacteria, especially regarding the bacterial GlmU enzyme. In this review, we provide an overview of different steps in PG biogenesis, discuss the biochemistry of GlmU, and summarize the characteristic structural elements of bacterial GlmU vital to its catalytic function. Finally, we will discuss various studies on the development of GlmU inhibitors and their significance in aiding future drug discoveries.
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Affiliation(s)
- Vijay Soni
- Division of Infectious Diseases, Weill Department of Medicine, Weill Cornell Medicine, New York, NY 10065, U.S.A
| | - Eric H Rosenn
- Tel Aviv University School of Medicine, Tel Aviv 6997801, Israel
| | - Ramya Venkataraman
- Laboratory of Innate Immunity, National Institute of Immunology, New Delhi 110067, India
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3
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Investigation of Plant Antimicrobial Peptides against Selected Pathogenic Bacterial Species Using a Peptide-Protein Docking Approach. BIOMED RESEARCH INTERNATIONAL 2022; 2022:1077814. [PMID: 35355819 PMCID: PMC8960006 DOI: 10.1155/2022/1077814] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 11/25/2021] [Accepted: 03/01/2022] [Indexed: 11/23/2022]
Abstract
Antimicrobial resistance is the key threat to global health due to high morbidity and mortality. The alteration of bacterial proteins, enzymatic degradation, and change of membrane permeability towards antimicrobial agents are the key mechanisms of antimicrobial resistance. Based on the current condition, there is an urgent clinical need to develop new drugs to treat these bacterial infections. In the current study, the binding patterns of selected antimicrobial peptides (AMPs) with different multidrug-resistant bacterial strains have been analyzed. Among ten selected AMPs in this study, napin and snakin-1 exhibited the best scores and binding patterns. Napin exhibited strong interactions with penicillin-binding protein 1a of Acinetobacter baumannii (with a binding score of -158.7 kcal/mol and ten hydrogen bonds), with glucose-1-phosphate thymidylyltransferase of Mycobacterium tuberculosis H37Rv (with a binding score of -107.8 kcal/mol and twelve hydrogen bonds), and with streptomycin 3″-adenylyltransferase protein of Salmonella enterica (with a binding score of -84.2 kcal/mol and four hydrogen bonds). Similarly, snakin-1 showed strong interactions with oxygen-insensitive NADPH nitroreductase of Helicobacter pylori (with a binding score of -105.0 kcal/mol and thirteen hydrogen bonds) and with penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus (with a binding score of -103.8 kcal/mol and twenty-three hydrogen bonds). The docking results were further validated by molecular dynamics simulations. The results of this computational approach support the evidence of efficiency of these AMPs as potent inhibitors of these specific proteins of bacterial strains. However, further validations are required to fully evaluate the potential of selected AMPs as drug candidates against these resistant bacterial strains.
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Brazel EB, Tan A, Neville SL, Iverson AR, Udagedara SR, Cunningham BA, Sikanyika M, De Oliveira DMP, Keller B, Bohlmann L, El-Deeb IM, Ganio K, Eijkelkamp BA, McEwan AG, von Itzstein M, Maher MJ, Walker MJ, Rosch JW, McDevitt CA. Dysregulation of Streptococcus pneumoniae zinc homeostasis breaks ampicillin resistance in a pneumonia infection model. Cell Rep 2022; 38:110202. [PMID: 35021083 PMCID: PMC9084593 DOI: 10.1016/j.celrep.2021.110202] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 09/24/2021] [Accepted: 12/13/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the primary cause of community-acquired bacterial pneumonia with rates of penicillin and multidrug-resistance exceeding 80% and 40%, respectively. The innate immune response generates a variety of antimicrobial agents to control infection, including zinc stress. Here, we characterize the impact of zinc intoxication on S. pneumoniae, observing disruptions in central carbon metabolism, lipid biogenesis, and peptidoglycan biosynthesis. Characterization of the pivotal peptidoglycan biosynthetic enzyme GlmU indicates a sensitivity to zinc inhibition. Disruption of the sole zinc efflux pathway, czcD, renders S. pneumoniae highly susceptible to β-lactam antibiotics. To dysregulate zinc homeostasis in the wild-type strain, we investigated the safe-for-human-use ionophore 5,7-dichloro-2-[(dimethylamino)methyl]quinolin-8-ol (PBT2). PBT2 rendered wild-type S. pneumoniae strains sensitive to a range of antibiotics. Using an invasive ampicillin-resistant strain, we demonstrate in a murine pneumonia infection model the efficacy of PBT2 + ampicillin treatment. These findings present a therapeutic modality to break antibiotic resistance in multidrug-resistant S. pneumoniae.
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Affiliation(s)
- Erin B Brazel
- Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Aimee Tan
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Stephanie L Neville
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Amy R Iverson
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Saumya R Udagedara
- School of Chemistry and the Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Bliss A Cunningham
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Mwilye Sikanyika
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3083, Australia
| | - David M P De Oliveira
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, QLD 4072, Australia
| | - Bernhard Keller
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, QLD 4072, Australia
| | - Lisa Bohlmann
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, QLD 4072, Australia
| | | | - Katherine Ganio
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia
| | - Bart A Eijkelkamp
- Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Alastair G McEwan
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, QLD 4072, Australia
| | | | - Megan J Maher
- School of Chemistry and the Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC 3000, Australia; Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3083, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences and Australian Infectious Diseases Research Centre, The University of Queensland, QLD 4072, Australia
| | - Jason W Rosch
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christopher A McDevitt
- Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC 3000, Australia.
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5
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Noda J, Tomizawa S, Takahashi K, Morimoto K, Mitarai S. Air pollution and airborne infection with mycobacterial bioaerosols: a potential attribution of soot. INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY : IJEST 2022; 19:717-726. [PMID: 33643419 PMCID: PMC7897364 DOI: 10.1007/s13762-021-03203-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 01/10/2021] [Accepted: 01/28/2021] [Indexed: 05/07/2023]
Abstract
Atmospheric pollutants are hypothesized to enhance the viability of airborne microbes by preventing them from degradation processes, thereby enhancing their atmospheric survival. In this study, Mycobacterium smegmatis is used as a model airborne bacteria, and different amounts of soot particles are employed as model air pollutants. The toxic effects of soot on aerosolized M. smegmatis are first evaluated and excluded by introducing them separately into a chamber, being sampled on a filter, and then cultured and counted. Secondly, the bacteria-soot mixture is exposed to UV with different durations and then cultured for bacterial viability evaluations. The results show that under UV exposure, the survival rates of the low-, medium-, and high-soot groups are 1.1 (±0.8) %, 70.9 (±4.3) %, and 61.0 (±17.6) %, respectively. This evidence significantly enhanced survival rates by soot at all UV exposures, though the combinations of UV exposure and soot amounts revealed a changing pattern of survival rates. The possible influence by direct and indirect effects of UV-damaging mechanisms is proposed. This study indicates the soot-induced survival rate enhancements of M. smegmatis under UV stress conditions, representing the possible relations between air pollution and the extended pathogenic viability and, therefore, increased airborne infection probability.
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Affiliation(s)
- J. Noda
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - S. Tomizawa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - K. Takahashi
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido Japan
| | - K. Morimoto
- Division of Clinical Research, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis Japan Anti-Tuberculosis Association, Tokyo, Japan
| | - S. Mitarai
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis Japan Anti-Tuberculosis Association, Tokyo, Japan
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6
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Gauttam R, Desiderato CK, Radoš D, Link H, Seibold GM, Eikmanns BJ. Metabolic Engineering of Corynebacterium glutamicum for Production of UDP-N-Acetylglucosamine. Front Bioeng Biotechnol 2021; 9:748510. [PMID: 34631687 PMCID: PMC8495162 DOI: 10.3389/fbioe.2021.748510] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/13/2021] [Indexed: 11/13/2022] Open
Abstract
Uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) is an acetylated amino sugar nucleotide that naturally serves as precursor in bacterial cell wall synthesis and is involved in prokaryotic and eukaryotic glycosylation reactions. UDP-GlcNAc finds application in various fields including the production of oligosaccharides and glycoproteins with therapeutic benefits. At present, nucleotide sugars are produced either chemically or in vitro by enzyme cascades. However, chemical synthesis is complex and non-economical, and in vitro synthesis requires costly substrates and often purified enzymes. A promising alternative is the microbial production of nucleotide sugars from cheap substrates. In this study, we aimed to engineer the non-pathogenic, Gram-positive soil bacterium Corynebacterium glutamicum as a host for UDP-GlcNAc production. The native glmS, glmU, and glmM genes and glmM of Escherichia coli, encoding the enzymes for UDP-GlcNAc synthesis from fructose-6-phosphate, were over-expressed in different combinations and from different plasmids in C. glutamicum GRS43, which lacks the glucosamine-6-phosphate deaminase gene (nagB) for glucosamine degradation. Over-expression of glmS, glmU and glmM, encoding glucosamine-6-phosphate synthase, the bifunctional glucosamine-1-phosphate acetyltransferase/N-acetyl glucosamine-1-phosphate uridyltransferase and phosphoglucosamine mutase, respectively, was confirmed using activity assays or immunoblot analysis. While the reference strain C. glutamicum GlcNCg1 with an empty plasmid in the exponential growth phase contained intracellularly only about 0.25 mM UDP-GlcNAc, the best engineered strain GlcNCg4 accumulated about 14 mM UDP-GlcNAc. The extracellular UDP-GlcNAc concentrations in the exponential growth phase did not exceed 2 mg/L. In the stationary phase, about 60 mg UDP-GlcNAc/L was observed extracellularly with strain GlcNCg4, indicating the potential of C. glutamicum to produce and to release the activated sugar into the culture medium. To our knowledge, the observed UDP-GlcNAc levels are the highest obtained with microbial hosts, emphasizing the potential of C. glutamicum as a suitable platform for activated sugar production.
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Affiliation(s)
- Rahul Gauttam
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | | | - Dušica Radoš
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Hannes Link
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Gerd M. Seibold
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
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Maitra A, Munshi T, Healy J, Martin LT, Vollmer W, Keep NH, Bhakta S. Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles' heel for the TB-causing pathogen. FEMS Microbiol Rev 2020; 43:548-575. [PMID: 31183501 PMCID: PMC6736417 DOI: 10.1093/femsre/fuz016] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis, remains one of the leading causes of mortality across the world. There is an urgent requirement to build a robust arsenal of effective antimicrobials, targeting novel molecular mechanisms to overcome the challenges posed by the increase of antibiotic resistance in TB. Mycobacterium tuberculosis has a unique cell envelope structure and composition, containing a peptidoglycan layer that is essential for maintaining cellular integrity and for virulence. The enzymes involved in the biosynthesis, degradation, remodelling and recycling of peptidoglycan have resurfaced as attractive targets for anti-infective drug discovery. Here, we review the importance of peptidoglycan, including the structure, function and regulation of key enzymes involved in its metabolism. We also discuss known inhibitors of ATP-dependent Mur ligases, and discuss the potential for the development of pan-enzyme inhibitors targeting multiple Mur ligases.
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Affiliation(s)
- Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Tulika Munshi
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Jess Healy
- Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Liam T Martin
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Nicholas H Keep
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
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Chen C, Han X, Yan Q, Wang C, Jia L, Taj A, Zhao L, Ma Y. The Inhibitory Effect of GlmU Acetyltransferase Inhibitor TPSA on Mycobacterium tuberculosis May Be Affected Due to Its Methylation by Methyltransferase Rv0560c. Front Cell Infect Microbiol 2019; 9:251. [PMID: 31380295 PMCID: PMC6652808 DOI: 10.3389/fcimb.2019.00251] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/27/2019] [Indexed: 01/01/2023] Open
Abstract
Mycobacterium tuberculosis bifunctional enzyme GlmU is a novel target for anti-TB drugs and is involved in glycosyl donor UDP-N-acetylglucosamine biosynthesis. Here, we found that TPSA (2-[5-(2-{[4-(2-thienyl)-2-pyrimidinyl]sulfanyl}acetyl)-2-thienyl]acetic acid) was a novel inhibitor for GlmU acetyltransferase activity (IC50: 5.3 μM). The interaction sites of GlmU and TPSA by molecular docking were confirmed by site-directed mutagenesis. TPSA showed an inhibitory effect on Mtb H37Ra growth and intracellular H37Ra in macrophage cells (MIC: 66.5 μM). To investigate why TPSA at a higher concentration (66.5 μM) was able to inhibit H37Ra growth, proteome and transcriptome of H37Ra treated with TPSA were analyzed. The expression of two methyltransferases MRA_0565 (Rv0558) and MRA_0567 (Rv0560c) were markedly increased. TPSA was pre-incubated with purified Rv0558 and Rv0560c in the presence of S-adenosylmethionine (methyl donor) respectively, resulting in its decreased inhibitory effect of GlmU on acetyltransferase activity. The inhibition of TPSA on growth of H37Ra with overexpressed Rv0558 and Rv0560c was reduced. These implied that methyltransferases could modify TPSA. The methylation of TPSA catalyzed by Rv0560c was subsequently confirmed by LC-MS. Therefore, TPSA as a GlmU acetyltransferase activity inhibitor may offer a structural basis for new anti-tuberculosis drugs. TPSA needs to be modified further by some groups to prevent its methylation by methyltransferases.
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Affiliation(s)
- Changming Chen
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Xiuyan Han
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Qiulong Yan
- Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Chao Wang
- College of Pharmacy, Dalian Medical University, Dalian, China
| | - Liqiu Jia
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Ayaz Taj
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Lizhe Zhao
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Yufang Ma
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China.,Department of Microbiology, College of Basic Medical Sciences, Dalian Medical University, Dalian, China
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Raghavendra T, Patil S, Mukherjee R. Peptidoglycan in Mycobacteria: chemistry, biology and intervention. Glycoconj J 2018; 35:421-432. [DOI: 10.1007/s10719-018-9842-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/20/2018] [Accepted: 09/05/2018] [Indexed: 01/07/2023]
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Ahangar MS, Furze CM, Guy CS, Cooper C, Maskew KS, Graham B, Cameron AD, Fullam E. Structural and functional determination of homologs of the Mycobacterium tuberculosis N-acetylglucosamine-6-phosphate deacetylase (NagA). J Biol Chem 2018; 293:9770-9783. [PMID: 29728457 PMCID: PMC6016474 DOI: 10.1074/jbc.ra118.002597] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/30/2018] [Indexed: 12/23/2022] Open
Abstract
The Mycobacterium tuberculosis (Mtb) pathogen encodes a GlcNAc-6-phosphate deacetylase enzyme, NagA (Rv3332), that belongs to the amidohydrolase superfamily. NagA enzymes catalyze the deacetylation of GlcNAc-6-phosphate (GlcNAc6P) to glucosamine-6-phosphate (GlcN6P). NagA is a potential antitubercular drug target because it represents the key enzymatic step in the generation of essential amino-sugar precursors required for Mtb cell wall biosynthesis and also influences recycling of cell wall peptidoglycan fragments. Here, we report the structural and functional characterization of NagA from Mycobacterium smegmatis (MSNagA) and Mycobacterium marinum (MMNagA), close relatives of Mtb. Using a combination of X-ray crystallography, site-directed mutagenesis, and biochemical and biophysical assays, we show that these mycobacterial NagA enzymes are selective for GlcNAc6P. Site-directed mutagenesis studies revealed crucial roles of conserved residues in the active site that underpin stereoselective recognition, binding, and catalysis of substrates. Moreover, we report the crystal structure of MSNagA in both ligand-free form and in complex with the GlcNAc6P substrate at 2.6 and 2.0 Å resolutions, respectively. The GlcNAc6P complex structure disclosed the precise mode of GlcNAc6P binding and the structural framework of the active site, including two divalent metals located in the α/β binuclear site. Furthermore, we observed a cysteine residue located on a flexible loop region that occludes the active site. This cysteine is unique to mycobacteria and may represent a unique subsite for targeting mycobacterial NagA enzymes. Our results provide critical insights into the structural and mechanistic properties of mycobacterial NagA enzymes having an essential role in amino-sugar and nucleotide metabolism in mycobacteria.
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Affiliation(s)
| | | | - Collette S Guy
- From the School of Life Sciences and.,the Department of Chemistry, University of Warwick, Warwick, Coventry CV4 7AL, United Kingdom
| | | | | | - Ben Graham
- the Department of Chemistry, University of Warwick, Warwick, Coventry CV4 7AL, United Kingdom
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Stiers KM, Xu J, Lee Y, Addison ZR, Van Doren SR, Beamer LJ. Phosphorylation-Dependent Effects on the Structural Flexibility of Phosphoglucosamine Mutase from Bacillus anthracis. ACS OMEGA 2017; 2:8445-8452. [PMID: 31457382 PMCID: PMC6645435 DOI: 10.1021/acsomega.7b01490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/16/2017] [Indexed: 06/09/2023]
Abstract
Phosphoglucosamine mutase (PNGM) is an evolutionarily conserved bacterial enzyme in the peptidoglycan biosynthetic pathway, catalyzing the reversible conversion between glucosamine 1- and 6-phosphate. Previous structural studies of PNGM from the pathogen Bacillus anthracis revealed its dimeric assembly and highlighted the rotational mobility of its C-terminal domain. Recent studies of two other enzymes in the same superfamily have demonstrated the long-range effects on the conformational flexibility associated with phosphorylation of the conserved, active site phosphoserine involved in phosphoryl transfer. Building on this work, we use a combination of experimental and computational studies to show that the active, phosphorylated version of B. anthracis PNGM has decreased flexibility relative to its inactive, dephosphorylated state. Limited proteolysis reveals an enhanced and accelerated cleavage of the dephosphorylated enzyme. 15N transverse relaxation-optimized NMR spectra corroborate a conformational adjustment with broadening and shifts of peaks relative to the phospho-enzyme. Electrostatic calculations indicate that residues in the mobile, C-terminal domain are linked to the phosphoserine by lines of attraction that are absent in the dephosphorylated enzyme. Phosphorylation-dependent changes in protein flexibility appear linked with the conformational change and enzyme mechanism in PNGM, establishing this as a conserved theme in multiple subgroups of the diverse α-d-phosphohexomutase superfamily.
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12
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Stiers KM, Muenks AG, Beamer LJ. Biology, Mechanism, and Structure of Enzymes in the α-d-Phosphohexomutase Superfamily. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 109:265-304. [PMID: 28683921 PMCID: PMC5802415 DOI: 10.1016/bs.apcsb.2017.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Enzymes in the α-d-phosphohexomutases superfamily catalyze the reversible conversion of phosphosugars, such as glucose 1-phosphate and glucose 6-phosphate. These reactions are fundamental to primary metabolism across the kingdoms of life and are required for a myriad of cellular processes, ranging from exopolysaccharide production to protein glycosylation. The subject of extensive mechanistic characterization during the latter half of the 20th century, these enzymes have recently benefitted from biophysical characterization, including X-ray crystallography, NMR, and hydrogen-deuterium exchange studies. This work has provided new insights into the unique catalytic mechanism of the superfamily, shed light on the molecular determinants of ligand recognition, and revealed the evolutionary conservation of conformational flexibility. Novel associations with inherited metabolic disease and the pathogenesis of bacterial infections have emerged, spurring renewed interest in the long-appreciated functional roles of these enzymes.
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Affiliation(s)
| | | | - Lesa J Beamer
- University of Missouri, Columbia, MO, United States.
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Abstract
The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick, carbohydrate- and lipid-rich cell wall with distinct lipoglycans enables mycobacteria to survive under hostile conditions such as shortage of nutrients and antimicrobial exposure. The key features of this highly complex cell wall are the mycolyl-arabinogalactan-peptidoglycan (mAGP)-based and phosphatidyl-myo-inositol-based macromolecular structures, with the latter possessing potent immunomodulatory properties. These structures are crucial for the growth, viability, and virulence of M. tuberculosis and therefore are often the targets of effective chemotherapeutic agents against tuberculosis. Over the past decade, sophisticated genomic and molecular tools have advanced our understanding of the primary structure and biosynthesis of these macromolecules. The availability of the full genome sequences of various mycobacterial species, including M. tuberculosis, Mycobacterium marinum, and Mycobacterium bovis BCG, have greatly facilitated the identification of large numbers of drug targets and antigens specific to tuberculosis. Techniques to manipulate mycobacteria have also improved extensively; the conditional expression-specialized transduction essentiality test (CESTET) is currently used to determine the essentiality of individual genes. Finally, various biosynthetic assays using either purified proteins or synthetic cell wall acceptors have been developed to study enzyme function. This article focuses on the recent advances in determining the structural details and biosynthesis of arabinogalactan, lipoarabinomannan, and related glycoconjugates.
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UDP-GlcNAc pathway: Potential target for inhibitor discovery against M. tuberculosis. Eur J Pharm Sci 2016; 83:62-70. [DOI: 10.1016/j.ejps.2015.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/29/2015] [Accepted: 12/08/2015] [Indexed: 11/23/2022]
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Jia X, Kang J, Yin H. A simple and rapid method for measuring α-D-phosphohexomutases activity by using anion-exchange chromatography coupled with an electrochemical detector. PeerJ 2016; 4:e1517. [PMID: 26788420 PMCID: PMC4715444 DOI: 10.7717/peerj.1517] [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: 07/02/2015] [Accepted: 11/27/2015] [Indexed: 11/20/2022] Open
Abstract
The interconversion of hexose-6-phosphate and hexose-1-phosphate can be directly analyzed by high-performance anion-exchange chromatography coupled with an electrochemical detector (HPAEC-PAD). Thus, this method can be used to measure the activities of N-acetylglucosamine-phosphate mutase (AGM), glucosamine-phosphate mutase (GlmM) and phosphoglucomutase (PGM), which are the members of α-D-phosphohexomutases superfamily. The detection limits were extremely low as 2.747 pmol, 1.365 pmol, 0.512 pmol, 0.415 pmol, 1.486 pmol and 0.868 pmol for N-acetylglucosamine-1-phosphate (GlcNAc-1-P), N-acetylglucosamine-6-phosphate (GlcNAc-6-P), glucosamine-1-phosphate (GlcN-1-P), glucosamine-6-phosphate (GlcN-6-P), glucose-1-phosphate (Glc-1-P) and glucose-6-phosphate (Glc-6-P), respectively. By employing HPAEC-PAD, activities of AtAGM (AGM from Arabidopsis thaliana) on these six phosphohexoses can be detected. The Km of AtAGM on Glc-1-P determined by HPAEC-PAD was 679.18 ± 156.40 µM, which is comparable with the Km of 707.09 ± 170.36 µM detected by traditional coupled assay. Moreover, the activity of MtGlmM (GlmM from Mycobacterium tuberculosis) on GlcN-6-P tested by HPAEC-PAD was 7493.40 ± 309.12 nmol∕min ⋅ mg, which is much higher than 288.97 ± 35.28 nmol∕min ⋅ mg obtained by the traditional coupled assay. Accordingly, HPAEC-PAD is a more rapid and simple method than the traditional coupled assays given its high specificity and sensitivity, and will certainly bring convenience to further research of α-D-phosphohexomutases.
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Affiliation(s)
- Xiaochen Jia
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jian Kang
- Department of Biochemistry and Molecular Biology, Dalian Medical University , Dalian , China
| | - Heng Yin
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian , China
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Alderwick LJ, Harrison J, Lloyd GS, Birch HL. The Mycobacterial Cell Wall--Peptidoglycan and Arabinogalactan. Cold Spring Harb Perspect Med 2015; 5:a021113. [PMID: 25818664 DOI: 10.1101/cshperspect.a021113] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The mycobacterial bacillus is encompassed by a remarkably elaborate cell wall structure. The mycolyl-arabinogalactan-peptidoglycan (mAGP) complex is essential for the viability of Mycobacterium tuberculosis and maintains a robust basal structure supporting the upper "myco-membrane." M. tuberculosis peptidoglycan, although appearing to be unexceptional at first glance, contains a number of unique molecular subtleties that become particularly important as the TB-bacilli enters into nonreplicative growth during dormancy. Arabinogalactan, a highly branched polysaccharide, serves to connect peptidoglycan with the outer mycolic acid layer, and a variety of unique glycolsyltransferases are used for its assembly. In this review, we shall explore the microbial chemistry of this unique heteropolysacchride, examine the molecular genetics that underpins its fabrication, and discuss how the essential biosynthetic process might be exploited for the development of future anti-TB chemotherapies.
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Affiliation(s)
- Luke J Alderwick
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - James Harrison
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Georgina S Lloyd
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Helen L Birch
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
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Angala SK, Belardinelli JM, Huc-Claustre E, Wheat WH, Jackson M. The cell envelope glycoconjugates of Mycobacterium tuberculosis. Crit Rev Biochem Mol Biol 2014; 49:361-99. [PMID: 24915502 PMCID: PMC4436706 DOI: 10.3109/10409238.2014.925420] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of the most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last 10 years in the discovery and development of novel inhibitors targeting their biogenesis.
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Affiliation(s)
- Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University , Fort Collins, CO , USA
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Qiu J, Ma Y, Owusu L, Jiang T, Xin Y. Functional analysis of serine acetyltransferase from Mycobacterium smegmatis. J Basic Microbiol 2014; 54:670-7. [PMID: 24652708 DOI: 10.1002/jobm.201300858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 02/07/2014] [Indexed: 11/08/2022]
Abstract
Serine acetyltransferase (CysE) is involved in L-cysteine biosynthesis in Mycobacterium, and it is important for the self-defense mechanism of the bacteria. Mycobacterium tuberculosis CysE (Rv2335) has been identified as a serine acetyltransferase, and it is orthologous to Mycobacterium smegmatis MSMEG_5947. In this study, the MSMEG_5947 gene was cloned, expressed, and identified as a serine acetyltransferase. To investigate the function of M. smegmatis CysE, a MSMEG_5947 knockout mutant strain (M. sm-ΔM_5947) was generated through homologous recombination. The growth and morphological characteristics of this strain were studied using growth curves and electron microscopy, respectively. M. sm-ΔM_5947 grew slower than M. smegmatis mc(2) 155. Electron microscopy revealed that the lack of the M. smegmatis CysE protein caused drastic morphological changes. Therefore, deletion of the serine acetyltransferase retards the growth of the Mycobacterium, but serine acetyltransferase expression is not essential for the survival of the bacteria.
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Affiliation(s)
- Juanjuan Qiu
- Centralab, the First Affiliated Hospital of Dalian Medical University, Dalian, China
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Kang J, Xu L, Yang S, Yu W, Liu S, Xin Y, Ma Y. Effect of phosphoglucosamine mutase on biofilm formation and antimicrobial susceptibilities in M. smegmatis glmM gene knockdown strain. PLoS One 2013; 8:e61589. [PMID: 23593488 PMCID: PMC3622608 DOI: 10.1371/journal.pone.0061589] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 03/11/2013] [Indexed: 11/18/2022] Open
Abstract
UDP-N-acetylglucosamine (UDP-GlcNAc) is a direct glycosyl donor of linker unit (L-Rhamnose-D-GlcNAc) and an essential precursor of peptidoglycan in mycobacteria. Phosphoglucosamine mutase (GlmM) is involved in the formation of glucosamine-1-phosphate from glucosamine-6-phosphate, the second step in UDP-GlcNAc biosynthetic pathway. We have demonstrated that GlmM protein is essential for the growth of M. smegmatis. To facilitate the analysis of the GlmM protein function in mycobacteria, a tetracycline inducible M. smegmatis glmM gene knockdown strain was constructed by using an antisense RNA technology. After induction with 20 ng/ml tetracycline, the expression of GlmM protein in glmM gene knockdown strain was significantly decreased, resulting in a decline of cell growth. The morphological changes of glmM gene knockdown strain induced with 20 ng/ml tetracycline have been observed by scanning electron microscope and transmission electron microscope. Furthermore, insufficient GlmM protein reduced the biofilm formation and increased the sensitivity to isoniazid and ethambutol in M. smegmatis, indicating that GlmM protein had effect on the biofilm formation and the senstivity to some anti-tuberculosis drugs targeting the cell wall. These results provide a new insight on GlmM functions in mycobacteria, suggesting that GlmM could be a potential target for development of new anti-tuberculosis drug.
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Affiliation(s)
- Jian Kang
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Liming Xu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Shufeng Yang
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Wendan Yu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Shuo Liu
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
| | - Yi Xin
- Department of Biotechnology, Dalian Medical University, Dalian, China
- Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, China
| | - Yufang Ma
- Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian, China
- Liaoning Provincial Core Lab of Glycobiology and Glycoengineering, Dalian, China
- * E-mail:
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