1
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Kim H, Shin SJ. Revolutionizing control strategies against Mycobacterium tuberculosis infection through selected targeting of lipid metabolism. Cell Mol Life Sci 2023; 80:291. [PMID: 37704889 PMCID: PMC11072447 DOI: 10.1007/s00018-023-04914-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 04/12/2023] [Accepted: 08/07/2023] [Indexed: 09/15/2023]
Abstract
Lipid species play a critical role in the growth and virulence expression of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB). During Mtb infection, foamy macrophages accumulate lipids in granulomas, providing metabolic adaptation and survival strategies for Mtb against multiple stresses. Host-derived lipid species, including triacylglycerol and cholesterol, can also contribute to the development of drug-tolerant Mtb, leading to reduced efficacy of antibiotics targeting the bacterial cell wall or transcription. Transcriptional and metabolic analyses indicate that lipid metabolism-associated factors of Mtb are highly regulated by antibiotics and ultimately affect treatment outcomes. Despite the well-known association between major antibiotics and lipid metabolites in TB treatment, a comprehensive understanding of how altered lipid metabolites in both host and Mtb influence treatment outcomes in a drug-specific manner is necessary to overcome drug tolerance. The current review explores the controversies and correlations between lipids and drug efficacy in various Mtb infection models and proposes novel approaches to enhance the efficacy of anti-TB drugs. Moreover, the review provides insights into the efficacious control of Mtb infection by elucidating the impact of lipids on drug efficacy. This review aims to improve the effectiveness of current anti-TB drugs and facilitate the development of innovative therapeutic strategies against Mtb infection by making reverse use of Mtb-favoring lipid species.
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Affiliation(s)
- Hagyu Kim
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea
| | - Sung Jae Shin
- Department of Microbiology, Institute for Immunology and Immunological Disease, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, South Korea.
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2
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Armianinova DK, Karpov DS, Kotliarova MS, Goncharenko AV. Genetic Engineering in Mycobacteria. Mol Biol 2022. [DOI: 10.1134/s0026893322060036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Abstract
Genetic tools for targeted modification of the mycobacterial genome contribute to the understanding of the physiology and virulence mechanisms of mycobacteria. Human and animal pathogens, such as the Mycobacterium tuberculosis complex, which causes tuberculosis, and M. leprae, which causes leprosy, are of particular importance. Genetic research opens up novel opportunities to identify and validate new targets for antibacterial drugs and to develop improved vaccines. Although mycobacteria are difficult to work with due to their slow growth rate and a limited possibility to transfer genetic information, significant progress has been made in developing genetic engineering methods for mycobacteria. The review considers the main approaches to changing the mycobacterial genome in a targeted manner, including homologous and site-specific recombination and use of the CRISPR/Cas system.
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3
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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4
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Ssekitoleko J, Ojok L, Abd El Wahed A, Erume J, Amanzada A, Eltayeb E, Eltom KH, Okuni JB. Mycobacterium avium subsp. paratuberculosis Virulence: A Review. Microorganisms 2021; 9:2623. [PMID: 34946224 PMCID: PMC8707695 DOI: 10.3390/microorganisms9122623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/08/2021] [Accepted: 12/16/2021] [Indexed: 11/17/2022] Open
Abstract
To propose a solution for control of Mycobacterium avium subsp. paratuberculosis (MAP) infections in animals as well as in humans, and develop effective prevention, diagnostic and treatment strategies, it is essential to understand the molecular mechanisms of MAP pathogenesis. In the present review, we discuss the mechanisms utilised by MAP to overcome the host defense system to achieve the virulence status. Putative MAP virulence genes are mentioned and their probable roles in view of other mycobacteria are discussed. This review provides information on MAP strain diversity, putative MAP virulence factors and highlights the knowledge gaps regarding MAP virulence mechanisms that may be important in control and prevention of paratuberculosis.
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Affiliation(s)
- Judah Ssekitoleko
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala P. O. Box 7062, Uganda; (J.S.); (L.O.); (J.E.)
- Department of Livestock Health Research, Rwebitaba Zonal Agricultural Research and Development Institute, National Agricultural Research Organisation, Entebbe P. O. Box 295, Uganda
| | - Lonzy Ojok
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala P. O. Box 7062, Uganda; (J.S.); (L.O.); (J.E.)
- Department of Pathology, Faculty of Medicine, Gulu University, Gulu P. O. Box 166, Uganda
| | - Ahmed Abd El Wahed
- Institute of Animal Hygiene and Veterinary Public Health, Leipzig University, D-04103 Leipzig, Germany
| | - Joseph Erume
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala P. O. Box 7062, Uganda; (J.S.); (L.O.); (J.E.)
| | - Ahmad Amanzada
- Department of Gastroenterology and Gastrointestinal Oncology, University Medical Centre Goettingen, D-37075 Goettingen, Germany;
| | - ElSagad Eltayeb
- Ibn Sina Specialised Hospital, Mohammed Najeeb St., Khartoum 11560, Sudan;
- Faculty of Medicine, Al Neelain University, 52nd St., Khartoum 11112, Sudan
| | - Kamal H. Eltom
- Unit of Animal Health and Safety of Animal Products, Institute for Studies and Promotion of Animal Exports, University of Khartoum, Shambat, Khartoum North 13314, Sudan;
| | - Julius Boniface Okuni
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala P. O. Box 7062, Uganda; (J.S.); (L.O.); (J.E.)
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5
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Patil V, Jain V. Understanding Metabolic Remodeling in Mycobacterium smegmatis to Overcome Energy Exigency and Reductive Stress Under Energy-Compromised State. Front Microbiol 2021; 12:722229. [PMID: 34539614 PMCID: PMC8440910 DOI: 10.3389/fmicb.2021.722229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/11/2021] [Indexed: 12/04/2022] Open
Abstract
Mycobacteria such as Mycobacterium tuberculosis, the causative agent of tuberculosis that annually kills several million people worldwide, and Mycobacterium smegmatis, the non-pathogenic fast-growing mycobacteria, require oxidative phosphorylation to meet their energy requirements. We have previously shown that deletion of one of the two copies of atpD gene that codes for the ATP synthase β-subunit establishes an energy-compromised state in M. smegmatis. Here we report that upon such deletion, a major routing of electron flux occurs through the less energy-efficient complexes of its respiratory chain. ΔatpD bacterium also shows an increased reduced state which is further confirmed by the overexpression of WhiB3, a major redox sensor. We show a substantial modulation of the biosynthesis of cell wall associated lipids and triacylglycerol (TAG). An accumulation of TAG-containing lipid bodies is further confirmed by using 14C oleate incorporation. Interestingly, the mutant also shows an overexpression of TAG-degrading lipase genes, and the intracellular lipolytic enzymes mediate TAG hydrolysis for their utilization as energy source. We believe that our in vitro energy-depleted model will allow us to explore the critical link between energy metabolism, redox homeostasis, and lipid biosynthesis during ATP-depleted state, which will enhance our understanding of the bacterial adaptation, and will allow us to identify novel drug targets to counter mycobacterial infections.
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Affiliation(s)
- Varsha Patil
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India
| | - Vikas Jain
- Microbiology and Molecular Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India
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6
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Roulet J, Galván V, Lara J, Salazar MO, Cholich V, Gramajo H, Arabolaza A. Modification of PapA5 acyltransferase substrate selectivity for optimization of short-chain alcohol-derived multimethyl-branched ester production in Escherichia coli. Appl Microbiol Biotechnol 2020; 104:8705-8718. [PMID: 32910267 DOI: 10.1007/s00253-020-10872-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/10/2020] [Accepted: 08/31/2020] [Indexed: 11/30/2022]
Abstract
Plant waxes are interesting substitutes of fossil-derived compounds; however, their limited sources and narrow structural diversity prompted the development of microbial platforms to produce esters with novel chemical structures and properties. One successful strategy was the heterologous expression of the mycocerosic polyketide synthase-based biosynthetic pathway (MAS-PKS, PapA5 and FadD28 enzymes) from Mycobacterium tuberculosis in Escherichia coli. This recombinant strain has the ability to produce a broad spectrum of multimethyl-branched long-chain esters (MBE) with novel chemical structures and high oxidation stability. However, one limitation of this microbial platform was the low yields obtained for MBE derived of short-chain alcohols. In an attempt to improve the titers of the short-chain alcohol-derived MBE, we focused on the PapA5 acyltransferase-enzyme that catalyzes the ester formation reaction. Specific amino acid residues located in the two-substrate recognition channels of this enzyme were identified, rationally mutated, and the corresponding mutants characterized both in vivo and in vitro. The phenylalanine located at 331 position in PapA5 (F331) was found to be a key residue that when substituted by other bulky and aromatic or bulky and polar amino acid residues (F331W, F331Y or F331H), gave rise to PapA5 mutants with improved bioconversion efficiency; showing in average, 2.5 higher yields of short-chain alcohol-derived MBE compared with the wild-type enzyme. Furthermore, two alternative pathways for synthetizing ethanol were engineered into the MBE producer microorganism, allowing de novo production of ethanol-derived MBE at levels comparable with those obtained by the external supply of this alcohol. KEY POINTS: • Mutation in channel 2 changes PapA5 acyltransferase bioconversion efficiency. • Improved production of short-chain alcohol derived multimethyl-branched esters. • Establishing ethanologenic pathways for de novo production of ethanol derived MBE. • Characterization of a novel phenylethanol-derived MBE.
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Affiliation(s)
- Julia Roulet
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Virginia Galván
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Julia Lara
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina.,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Mario O Salazar
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Valeria Cholich
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina
| | - Hugo Gramajo
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
| | - Ana Arabolaza
- IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ocampo y Esmeralda, 2000, Rosario, Argentina. .,Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000, Rosario, Argentina.
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7
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Booth TJ, Kalaitzis JA, Vuong D, Crombie A, Lacey E, Piggott AM, Wilkinson B. Production of novel pladienolide analogues through native expression of a pathway-specific activator. Chem Sci 2020; 11:8249-8255. [PMID: 34094178 PMCID: PMC8163091 DOI: 10.1039/d0sc01928c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aberrant splicing of pre-mRNA is implicated in many human genetic disorders. Small molecules that target the spliceosome are important leads as therapeutics and research tools, and one compound of significant interest is the polyketide natural product pladienolide B. Here, we describe the reactivation of quiescent pladienolide B production in the domesticated lab strain Streptomyces platensis AS6200 by overexpression of the pathway-specific activator PldR. The resulting dysregulation of the biosynthetic genes led to the accumulation and isolation of five additional intermediate or shunt metabolites of pladienolide B biosynthesis, including three previously unreported congeners. These compounds likely comprise the entire pladienolide biosynthetic pathway and demonstrate the link between polyketide tailoring reactions and bioactivity, particularly the importance of the 18,19-epoxide. Each congener demonstrated specific inhibitory activity against mammalian cell lines, with successive modifications leading to increased activity (IC50: 8 mM to 5 μM). Reactivation of quiescent polyketide production in a domesticated lab strain.![]()
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Affiliation(s)
- Thomas J Booth
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
| | - John A Kalaitzis
- Department of Molecular Sciences, Macquarie University NSW 2109 Australia
| | - Daniel Vuong
- Microbial Screening Technologies Smithfield NSW 2164 Australia
| | - Andrew Crombie
- Microbial Screening Technologies Smithfield NSW 2164 Australia
| | - Ernest Lacey
- Microbial Screening Technologies Smithfield NSW 2164 Australia
| | - Andrew M Piggott
- Department of Molecular Sciences, Macquarie University NSW 2109 Australia
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre Norwich Research Park Norwich NR4 7UH UK
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8
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Ma S, Huang Y, Xie F, Gong Z, Zhang Y, Stojkoska A, Xie J. Transport mechanism of Mycobacterium tuberculosis MmpL/S family proteins and implications in pharmaceutical targeting. Biol Chem 2020; 401:331-348. [DOI: 10.1515/hsz-2019-0326] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 09/06/2019] [Indexed: 12/13/2022]
Abstract
AbstractTuberculosis caused by Mycobacterium tuberculosis remains a serious threat to public health. The M. tuberculosis cell envelope is closely related to its virulence and drug resistance. Mycobacterial membrane large proteins (MmpL) are lipid-transporting proteins of the efflux pump resistance nodulation cell division (RND) superfamily with lipid substrate specificity and non-transport lipid function. Mycobacterial membrane small proteins (MmpS) are small regulatory proteins, and they are also responsible for some virulence-related effects as accessory proteins of MmpL. The MmpL transporters are the candidate targets for the development of anti-tuberculosis drugs. This article summarizes the structure, function, phylogenetics of M. tuberculosis MmpL/S proteins and their roles in host immune response, inhibitors and regulatory system.
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Affiliation(s)
- Shuang Ma
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Yu Huang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Fuling Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Zhen Gong
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Yuan Zhang
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Andrea Stojkoska
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Chongqing 400700, China
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9
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Tran T, Bonham AJ, Chan ED, Honda JR. A paucity of knowledge regarding nontuberculous mycobacterial lipids compared to the tubercle bacillus. Tuberculosis (Edinb) 2019; 115:96-107. [PMID: 30948183 DOI: 10.1016/j.tube.2019.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/29/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
Abstract
All mycobacteria, including nontuberculous mycobacteria (NTM), synthesize an array of lipids including phosphatidylinositol mannosides (PIM), lipomannan (LM), and lipoarabinomannan (LAM). While absent from Mycobacterium tuberculosis (M. tb), glycopeptidolipids (GPL) are critical to the biology of NTM. M. tb and some NTM also synthesize trehalose-containing glycolipids and phenolic glycolipids (PGL), key membrane constituents with essential roles in metabolism. While lipids facilitate immune evasion, they also induce host immunity against tuberculosis. However, much less is known about the significance of NTM-derived PIM, LM, LAM, GPL, trehalose-containing glycolipids, and PGL as virulence factors, warranting further investigation. While culling the scientific literature on NTM lipids, it's evident that such studies were relatively few in number with the overwhelming majority of prior work dedicated to understanding lipids from the saprophyte Mycobacterium smegmatis. The identification and functional analysis of immune reactive NTM-derived lipids remain challenging, but such work is likely to yield a greater understanding of the pathogenesis of NTM lung disease. In this review, we juxtapose the vast literature of what is currently known regarding M. tb lipids to the lesser number of studies for comparable NTM lipids. But because GPL is the most widely recognized NTM lipid, we highlight its role in disease pathogenesis.
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Affiliation(s)
- Tru Tran
- Department of Integrative Biology, University of Colorado Denver, Campus Box 171, PO Box 173364, Denver, CO, 80217-3364, USA.
| | - Andrew J Bonham
- Department of Chemistry, Metropolitan State University of Denver, Campus Box 52, P.O. Box 173362, Denver, CO, 80217-3362, USA.
| | - Edward D Chan
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; Department of Medicine, Denver Veterans Affairs Medical Center, Denver, CO, USA; Academic Affairs, National Jewish Health, 1400 Jackson St. Neustadt D509, Denver, CO, 80206, USA.
| | - Jennifer R Honda
- Department of Biomedical Research and the Center for Genes, Environment, and Health, National Jewish Health, Denver, CO, USA.
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10
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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11
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Abstract
Covering: up to mid of 2018 Type I fatty acid synthases (FASs) are giant multienzymes catalyzing all steps of the biosynthesis of fatty acids from acetyl- and malonyl-CoA by iterative precursor extension. Two strikingly different architectures of FAS evolved in yeast (as well as in other fungi and some bacteria) and metazoans. Yeast-type FAS (yFAS) assembles into a barrel-shaped structure of more than 2 MDa molecular weight. Catalytic domains of yFAS are embedded in an extensive scaffolding matrix and arranged around two enclosed reaction chambers. Metazoan FAS (mFAS) is a 540 kDa X-shaped dimer, with lateral reaction clefts, minimal scaffolding and pronounced conformational variability. All naturally occurring yFAS are strictly specialized for the production of saturated fatty acids. The yFAS architecture is not used for the biosynthesis of any other secondary metabolite. On the contrary, mFAS is related at the domain organization level to major classes of polyketide synthases (PKSs). PKSs produce a variety of complex and potent secondary metabolites; they either act iteratively (iPKS), or are linked via directed substrate transfer into modular assembly lines (modPKSs). Here, we review the architectures of yFAS, mFAS, and iPKSs. We rationalize the evolution of the yFAS assembly, and provide examples for re-engineering of yFAS. Recent studies have provided novel insights into the organization of iPKS. A hybrid crystallographic model of a mycocerosic acid synthase-like Pks5 yielded a comprehensive visualization of the organization and dynamics of fully-reducing iPKS. Deconstruction experiments, structural and functional studies of specialized enzymatic domains, such as the product template (PT) and the starter-unit acyltransferase (SAT) domain have revealed functional principles of non-reducing iterative PKS (NR-PKSs). Most recently, a six-domain loading region of an NR-PKS has been visualized at high-resolution together with cryo-EM studies of a trapped loading intermediate. Altogether, these data reveal the related, yet divergent architectures of mFAS, iPKS and also modPKSs. The new insights highlight extensive dynamics, and conformational coupling as key features of mFAS and iPKS and are an important step towards collection of a comprehensive series of snapshots of PKS action.
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Affiliation(s)
- Dominik A Herbst
- Department Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
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12
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Xue SJ, Chi Z, Zhang Y, Li YF, Liu GL, Jiang H, Hu Z, Chi ZM. Fatty acids from oleaginous yeasts and yeast-like fungi and their potential applications. Crit Rev Biotechnol 2018; 38:1049-1060. [DOI: 10.1080/07388551.2018.1428167] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Si-Jia Xue
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhe Chi
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yu Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yan-Feng Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Guang-Lei Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Hong Jiang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Zhong Hu
- Department of Biology, Shantou University, Shantou, China
| | - Zhen-Ming Chi
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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13
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Faille A, Gavalda S, Slama N, Lherbet C, Maveyraud L, Guillet V, Laval F, Quémard A, Mourey L, Pedelacq JD. Insights into Substrate Modification by Dehydratases from Type I Polyketide Synthases. J Mol Biol 2017; 429:1554-1569. [PMID: 28377293 DOI: 10.1016/j.jmb.2017.03.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 02/04/2023]
Abstract
Dehydration reactions play a crucial role in the de novo biosynthesis of fatty acids and a wide range of pharmacologically active polyketide natural products with strong emphasis on human medicine. The type I polyketide synthase PpsC from Mycobacterium tuberculosis catalyzes key biosynthetic steps of lipid virulence factors phthiocerol dimycocerosates and phenolic glycolipids. Given the insolubility of the natural C28-C30 fatty acyl substrate of the PpsC dehydratase (DH) domain, we investigated its structure-function relationships in the presence of shorter surrogate substrates. Since most enzymes belonging to the (R)-specific enoyl hydratase/hydroxyacyl dehydratase family conduct the reverse hydration reaction in vitro, we have determined the X-ray structures of the PpsC DH domain, both unliganded (apo) and in complex with trans-but-2-enoyl-CoA or trans-dodec-2-enoyl-CoA derivatives. This study provides for the first time a snapshot of dehydratase-ligand interactions following a hydration reaction. Our structural analysis allowed us to identify residues essential for substrate binding and activity. The structural comparison of the two complexes also sheds light on the need for long acyl chains for this dehydratase to carry out its function, consistent with both its in vitro catalytic behavior and the physiological role of the PpsC enzyme.
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Affiliation(s)
- Alexandre Faille
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Sabine Gavalda
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Nawel Slama
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | | | - Laurent Maveyraud
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Françoise Laval
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Annaïk Quémard
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France.
| | - Jean-Denis Pedelacq
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse Cedex 04, France.
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14
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Kadlcik S, Kamenik Z, Vasek D, Nedved M, Janata J. Elucidation of salicylate attachment in celesticetin biosynthesis opens the door to create a library of more efficient hybrid lincosamide antibiotics. Chem Sci 2017; 8:3349-3355. [PMID: 28507704 PMCID: PMC5416915 DOI: 10.1039/c6sc04235j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 02/27/2017] [Indexed: 11/21/2022] Open
Abstract
Combinatorial biosynthesis for more efficient antibiotics: 150 novel lincosamides prepared by combining lincomycin and celesticetin biosynthetic pathways.
Lincosamides, which are produced by streptomycetes, compose a small but clinically important class of antibiotics. The recent elucidation of the condensation and post-condensation biosynthetic steps of the lincosamides lincomycin and celesticetin revealed several unexpected reaction mechanisms. Here, we prepared recombinant proteins involved in the celesticetin biosynthetic pathway and used them for in vitro assays that were monitored by LC-MS. Our results elucidate the last biosynthetic step of celesticetin: the attachment of salicylic acid is catalyzed by the Ccb2 acyl-CoA ligase and the Ccb1 acyltransferase. Ccb1 belongs to the WS/DGAT protein family and, in contrast to the characterized members of the family, has unusual substrate specificity. To the best of our knowledge, Ccb1 is the first protein in this family that transfers a benzoyl derivative-CoA conjugate and is the first WS/DGAT protein involved in the biosynthesis of secondary metabolites. Furthermore, we exploited the relaxed substrate specificities of Ccb1 and Ccb2, as well as three additional upstream post-condensation biosynthetic proteins in the celesticetin pathway, and combined the lincomycin and the celesticetin biosynthetic pathways in vitro. In this way, we prepared a library of 150 novel hybrid lincosamides, including two unnatural chimeras of lincomycin and celesticetin, which were shown to have antibacterial properties more pronounced than clinically used lincomycin. These achievements may be considered a case study in applying knowledge about biosynthetic machinery to assemble a large number of compounds from originally a small group of natural products without the need for chemical synthesis.
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Affiliation(s)
- S Kadlcik
- Institute of Microbiology , Czech Academy of Sciences , BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic .
| | - Z Kamenik
- Institute of Microbiology , Czech Academy of Sciences , BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic .
| | - D Vasek
- Institute of Microbiology , Czech Academy of Sciences , BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic .
| | - M Nedved
- Institute of Microbiology , Czech Academy of Sciences , BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic .
| | - J Janata
- Institute of Microbiology , Czech Academy of Sciences , BIOCEV , Prumyslova 595 , 252 50 Vestec , Czech Republic .
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15
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Menendez-Bravo S, Comba S, Gramajo H, Arabolaza A. Metabolic engineering of microorganisms for the production of structurally diverse esters. Appl Microbiol Biotechnol 2017; 101:3043-3053. [PMID: 28275821 DOI: 10.1007/s00253-017-8179-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 02/02/2017] [Accepted: 02/03/2017] [Indexed: 11/25/2022]
Abstract
Conventional petroleum-based chemical industry, although economically still thriving, is now facing great socio-political challenges due to the increasing concerns on climate change and limited availability of fossil resources. In this context, microbial production of fuels and commodity oleochemicals from renewable biomass is being considered a promising sustainable alternative. The increasing understanding of cellular systems has enabled the redesign of microbial metabolism for the production of compounds present in many daily consumer products such as esters, waxes, fatty acids (FA) and fatty alcohols. Small aliphatic esters are important flavour and fragrance elements while long-chain esters, composed of FA esterified to fatty alcohols, are widely used in lubricant formulas, paints, coatings and cosmetics. Here, we review recent advances in the biosynthesis of these types of mono alkyl esters in vivo. We focus on the critical ester bond-forming enzymes and the latest metabolic engineering strategies employed for the biosynthesis of a wide range of products ranging from low-molecular-weight esters to waxy compounds.
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Affiliation(s)
- Simón Menendez-Bravo
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Santiago Comba
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Hugo Gramajo
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda (2000), Rosario, Argentina.
| | - Ana Arabolaza
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Ocampo y Esmeralda (2000), Rosario, Argentina.
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16
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Abstract
Mycobacterium leprae must adopt a metabolic strategy and undergo various metabolic alterations upon infection to survive inside the human body for years in a dormant state. A change in lipid homeostasis upon infection is highly pronounced in Mycobacterium leprae. Lipids play an essential role in the survival and pathogenesis of mycobacteria. Lipids are present in several forms and serve multiple roles from being a source of nutrition, providing rigidity, evading the host immune response to serving as virulence factors, etc. The synthesis and degradation of lipids is a highly regulated process and is the key to future drug designing and diagnosis for mycobacteria. In the current review, an account of the distinct roles served by lipids, the mechanism of their synthesis and degradation has been elucidated.
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Affiliation(s)
- Gurkamaljit Kaur
- Research Scholar, Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
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17
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Abstract
This article summarizes what is currently known of the structures, physiological roles, involvement in pathogenicity, and biogenesis of a variety of noncovalently bound cell envelope lipids and glycoconjugates of Mycobacterium tuberculosis and other Mycobacterium species. Topics addressed in this article include phospholipids; phosphatidylinositol mannosides; triglycerides; isoprenoids and related compounds (polyprenyl phosphate, menaquinones, carotenoids, noncarotenoid cyclic isoprenoids); acyltrehaloses (lipooligosaccharides, trehalose mono- and di-mycolates, sulfolipids, di- and poly-acyltrehaloses); mannosyl-beta-1-phosphomycoketides; glycopeptidolipids; phthiocerol dimycocerosates, para-hydroxybenzoic acids, and phenolic glycolipids; mycobactins; mycolactones; and capsular polysaccharides.
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18
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pks5-recombination-mediated surface remodelling in Mycobacterium tuberculosis emergence. Nat Microbiol 2016; 1:15019. [PMID: 27571976 DOI: 10.1038/nmicrobiol.2015.19] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/19/2015] [Indexed: 01/09/2023]
Abstract
Mycobacterium tuberculosis is a major, globally spread, aerosol-transmitted human pathogen, thought to have evolved by clonal expansion from a Mycobacterium canettii-like progenitor. In contrast, extant M. canettii strains are rare, genetically diverse, and geographically restricted mycobacteria of only marginal epidemiological importance. Here, we show that the contrasting evolutionary success of these two groups is linked to loss of lipooligosaccharide biosynthesis and subsequent morphotype changes. Spontaneous smooth-to-rough M. canettii variants were found to be mutated in the polyketide-synthase-encoding pks5 locus and deficient in lipooligosaccharide synthesis, a phenotype restored by complementation. Importantly, these rough variants showed an altered host-pathogen interaction and increased virulence in cellular- and animal-infection models. In one variant, lipooligosaccharide deficiency occurred via homologous recombination between two pks5 genes and removal of the intervening acyltransferase-encoding gene. The resulting single pks5 configuration is similar to that fixed in M. tuberculosis, which is known to lack lipooligosaccharides. Our results suggest that pks5-recombination-mediated bacterial surface remodelling increased virulence, driving evolution from putative generalist mycobacteria towards professional pathogens of mammalian hosts.
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19
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Menendez-Bravo S, Roulet J, Sabatini M, Comba S, Dunn R, Gramajo H, Arabolaza A. High cell density production of multimethyl-branched long-chain esters in Escherichia coli and determination of their physicochemical properties. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:215. [PMID: 27757170 PMCID: PMC5064953 DOI: 10.1186/s13068-016-0631-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/28/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND Microbial synthesis of oleochemicals derived from native fatty acid (FA) metabolism has presented significant advances in recent years. Even so, native FA biosynthetic pathways often provide a narrow variety of usually linear hydrocarbons, thus yielding end products with limited structural diversity. To overcome this limitation, we took advantage of a polyketide synthase-based system from Mycobacterium tuberculosis and developed an Escherichia coli platform with the capacity to synthesize multimethyl-branched long-chain esters (MBE) with novel chemical structures. RESULTS With the aim to initiate the characterization of these novel waxy compounds, here, we describe the chassis optimization of the MBE producer E. coli strain for an up-scaled oil production. By carrying out systematic metabolic engineering, we improved the final titer to 138.1 ± 5.3 mg MBE L-1 in batch cultures. Fed-batch microbial fermentation process was also optimized achieving a maximum yield of 790.2 ± 6.9 mg MBE L-1 with a volumetric productivity of 15.8 ± 1.1 mg MBE (L h)-1. Purified MBE oil was subjected to various physicochemical analyses, including differential scanning calorimetry (DSC) and pressurized-differential scanning calorimetry (P-DSC) studies. CONCLUSIONS The analysis of the pour point, DSC, and P-DSC data obtained showed that bacterial MBE possess improved cold flow properties than several plant oils and some chemically modified derivatives, while exhibiting high oxidation stability at elevated temperatures. These encouraging data indicate that the presence of multiple methyl branches in these novel esters, indeed, conferred favorable properties which are superior to those of linear esters.
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Affiliation(s)
- Simón Menendez-Bravo
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Julia Roulet
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Martín Sabatini
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Santiago Comba
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Robert Dunn
- US Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University St, Peoria, IL 61604 USA
| | - Hugo Gramajo
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
| | - Ana Arabolaza
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda (2000), Rosario, Argentina
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20
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Chiu HT, Weng CP, Lin YC, Chen KH. Target-specific identification and characterization of the putative gene cluster for brasilinolide biosynthesis revealing the mechanistic insights and combinatorial synthetic utility of 2-deoxy-l-fucose biosynthetic enzymes. Org Biomol Chem 2016; 14:1988-2006. [DOI: 10.1039/c5ob02292d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
From Nocardia was cloned and functionally characterized a giant gene cluster for biosyntheses of brasilinolides as potent immunosuppressive and anticancer agents.
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Affiliation(s)
- Hsien-Tai Chiu
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
| | - Chien-Pao Weng
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
| | - Yu-Chin Lin
- Department of Chemistry
- National Cheng Kung University
- Tainan 701
- Taiwan
- Department of Biological Science and Technology
| | - Kuan-Hung Chen
- Department of Biological Science and Technology
- National Chiao Tung University
- Hsinchu 300
- Taiwan
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21
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Touchette MH, Bommineni GR, Delle Bovi RJ, Gadbery JE, Nicora CD, Shukla AK, Kyle JE, Metz TO, Martin DW, Sampson NS, Miller WT, Tonge PJ, Seeliger JC. Diacyltransferase Activity and Chain Length Specificity of Mycobacterium tuberculosis PapA5 in the Synthesis of Alkyl β-Diol Lipids. Biochemistry 2015; 54:5457-68. [PMID: 26271001 DOI: 10.1021/acs.biochem.5b00455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although they are classified as Gram-positive bacteria, Corynebacterineae possess an asymmetric outer membrane that imparts structural and thereby physiological similarity to more distantly related Gram-negative bacteria. Like lipopolysaccharide in Gram-negative bacteria, lipids in the outer membrane of Corynebacterineae have been associated with the virulence of pathogenic species such as Mycobacterium tuberculosis (Mtb). For example, Mtb strains that lack long, branched-chain alkyl esters known as dimycocerosates (DIMs) are significantly attenuated in model infections. The resultant interest in the biosynthetic pathway of these unusual virulence factors has led to the elucidation of many of the steps leading to the final esterification of the alkyl β-diol, phthiocerol, with branched-chain fatty acids known as mycocerosates. PapA5 is an acyltransferase implicated in these final reactions. Here, we show that PapA5 is indeed the terminal enzyme in DIM biosynthesis by demonstrating its dual esterification activity and chain-length preference using synthetic alkyl β-diol substrate analogues. By applying these analogues to a series of PapA5 mutants, we also revise a model for the substrate binding within PapA5. Finally, we demonstrate that the Mtb Ser/Thr kinases PknB and PknE modify PapA5 on three overlapping Thr residues and that a fourth Thr is unique to PknE phosphorylation. These results clarify the DIM biosynthetic pathway and indicate post-translational modifications that warrant further elucidation for their roles in the regulation of DIM biosynthesis.
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Affiliation(s)
| | | | | | | | - Carrie D Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Anil K Shukla
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Jennifer E Kyle
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Thomas O Metz
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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22
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Abstract
The bifunctional wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT or wax ester synthase) catalyzes the terminal reaction in the bacterial wax ester biosynthetic pathway, utilizing a range of alcohols and fatty acyl-CoAs to synthesize the corresponding wax ester. The wild-type wax ester synthase Maqu_0168 from Marinobacter aquaeolei VT8 exhibits a preference for longer fatty alcohols, while applications with smaller alcohols would yield products with desired biotechnological properties. Small and medium chain length alcohol substrates are much poorer substrates for the native enzyme, which may hinder broad application of the wax ester synthase in many proposed biosynthetic schemes. Developing approaches to improve enzyme activity toward specific smaller alcohol substrates first requires a clear understanding of which amino acids of the primary sequences of these enzymes contribute to substrate specificity in the native enzyme. In this report, we surveyed a range of potential residues and identified the leucine at position 356 and methionine at position 405 in Maqu_0168 as residues that affected selectivity toward small, branched, and aromatic alcohols when substituted with different amino acids. This analysis provides evidence of residues that line the binding site for wax ester synthase, which will aid rational approaches to improve this enzyme with specific substrates.
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23
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Taylor MS, Dempsey DR, Hwang Y, Chen Z, Chu N, Boeke JD, Cole PA. Mechanistic analysis of ghrelin-O-acyltransferase using substrate analogs. Bioorg Chem 2015; 62:64-73. [PMID: 26246082 DOI: 10.1016/j.bioorg.2015.07.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 11/15/2022]
Abstract
Ghrelin-O-Acyltransferase (GOAT) is an 11-transmembrane integral membrane protein that octanoylates the metabolism-regulating peptide hormone ghrelin at Ser3 and may represent an attractive target for the treatment of type II diabetes and the metabolic syndrome. Protein octanoylation is unique to ghrelin in humans, and little is known about the mechanism of GOAT or of related protein-O-acyltransferases HHAT or PORC. In this study, we explored an in vitro microsomal ghrelin octanoylation assay to analyze its enzymologic features. Measurement of Km for 10-mer, 27-mer, and synthetic Tat-peptide-containing ghrelin substrates provided evidence for a role of charge interactions in substrate binding. Ghrelin substrates with amino-alanine in place of Ser3 demonstrated that GOAT can catalyze the formation of an octanoyl-amide bond at a similar rate compared with the natural reaction. A pH-rate comparison of these substrates revealed minimal differences in acyltransferase activity across pH 6.0-9.0, providing evidence that these reactions may be relatively insensitive to the basicity of the substrate nucleophile. The conserved His338 residue was required both for Ser3 and amino-Ala3 ghrelin substrates, suggesting that His338 may have a key catalytic role beyond that of a general base.
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Affiliation(s)
- Martin S Taylor
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Molecular Biology & Genetics and High Throughput Biology Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel R Dempsey
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yousang Hwang
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zan Chen
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nam Chu
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jef D Boeke
- Department of Molecular Biology & Genetics and High Throughput Biology Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Philip A Cole
- Department of Pharmacology & Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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24
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Biosynthesis of cell envelope-associated phenolic glycolipids in Mycobacterium marinum. J Bacteriol 2015; 197:1040-50. [PMID: 25561717 DOI: 10.1128/jb.02546-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phenolic glycolipids (PGLs) are polyketide synthase-derived glycolipids unique to pathogenic mycobacteria. PGLs are found in several clinically relevant species, including various Mycobacterium tuberculosis strains, Mycobacterium leprae, and several nontuberculous mycobacterial pathogens, such as M. marinum. Multiple lines of investigation implicate PGLs in virulence, thus underscoring the relevance of a deep understanding of PGL biosynthesis. We report mutational and biochemical studies that interrogate the mechanism by which PGL biosynthetic intermediates (p-hydroxyphenylalkanoates) synthesized by the iterative polyketide synthase Pks15/1 are transferred to the noniterative polyketide synthase PpsA for acyl chain extension in M. marinum. Our findings support a model in which the transfer of the intermediates is dependent on a p-hydroxyphenylalkanoyl-AMP ligase (FadD29) acting as an intermediary between the iterative and the noniterative synthase systems. Our results also establish the p-hydroxyphenylalkanoate extension ability of PpsA, the first-acting enzyme of a multisubunit noniterative polyketide synthase system. Notably, this noniterative system is also loaded with fatty acids by a specific fatty acyl-AMP ligase (FadD26) for biosynthesis of phthiocerol dimycocerosates (PDIMs), which are nonglycosylated lipids structurally related to PGLs. To our knowledge, the partially overlapping PGL and PDIM biosynthetic pathways provide the first example of two distinct, pathway-dedicated acyl-AMP ligases loading the same type I polyketide synthase system with two alternate starter units to produce two structurally different families of metabolites. The studies reported here advance our understanding of the biosynthesis of an important group of mycobacterial glycolipids.
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25
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The Polyketide Synthase Pks13 Catalyzes a Novel Mechanism of Lipid Transfer in Mycobacteria. ACTA ACUST UNITED AC 2014; 21:1660-9. [DOI: 10.1016/j.chembiol.2014.10.011] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022]
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26
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Menendez-Bravo S, Comba S, Sabatini M, Arabolaza A, Gramajo H. Expanding the chemical diversity of natural esters by engineering a polyketide-derived pathway into Escherichia coli. Metab Eng 2014; 24:97-106. [DOI: 10.1016/j.ymben.2014.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 04/29/2014] [Accepted: 05/05/2014] [Indexed: 01/25/2023]
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27
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Wei J, Liang J, Shi Q, Yuan P, Meng R, Tang X, Yu L, Guo N. Genome-wide transcription analyses in Mycobacterium tuberculosis treated with lupulone. Braz J Microbiol 2014; 45:333-41. [PMID: 24948953 PMCID: PMC4059319 DOI: 10.1590/s1517-83822014005000032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 04/01/2013] [Indexed: 01/16/2023] Open
Abstract
Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, still causes higher mortality than any other bacterial pathogen until now. With the emergence and spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR-TB) strains, it becomes more important to search for alternative targets to develop new antimycobacterial drugs. Lupulone is a compound extracted from Hops (Hurnulus lupulus), which exhibits a good antimicrobial activity against M. tuberculosis with minimal inhibitory concentration (MIC) value of 10 μg/mL, but the response mechanisms of lupulone against M. tuberculosis are still poorly understood. In this study, we used a commercial oligonucleotide microarray to determine the overall transcriptional response of M. tuberculosis H37Rv triggered by exposure to MIC of lupulone. A total of 540 genes were found to be differentially regulated by lupulone. Of these, 254 genes were upregulated, and 286 genes were downregulated. A number of important genes were significantly regulated which are involved in various pathways, such as surface-exposed lipids, cytochrome P450 enzymes, PE/PPE multigene families, ABC transporters, and protein synthesis. Real-time quantitative RT-PCR was performed for choosed genes to verified the microarray results. To our knowledge, this genome-wide transcriptomics approach has produced the first insights into the response of M. tuberculosis to a lupulone challenge.
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Affiliation(s)
- Jian Wei
- Life Science Department ChangChun Normal University Changchun P.R. China ; Bio-Reactor Center Jilin Agrichultural University Changchun P.R. China
| | - Junchao Liang
- Department of Food Quality and Safety Key Laboratory of Zoonosis Research Institute of Zoonosis Ministry of Education Changchun P. R. China
| | - Qiyun Shi
- Department of Food Quality and Safety Key Laboratory of Zoonosis Research Institute of Zoonosis Ministry of Education Changchun P. R. China
| | - Peng Yuan
- Department of Food Quality and Safety Key Laboratory of Zoonosis Research Institute of Zoonosis Ministry of Education Changchun P. R. China
| | - Rizeng Meng
- Jilin Enrty-Exit Inspection and Quarantine Bureau Changchun P.R. China
| | - Xudong Tang
- Key Lab for New Drug Research of TCM Research Institute of Tsinghua University in Shenzhen Shenzhen P.R. China
| | - Lu Yu
- Department of Food Quality and Safety Key Laboratory of Zoonosis Research Institute of Zoonosis Ministry of Education Changchun P. R. China
| | - Na Guo
- Department of Food Quality and Safety Key Laboratory of Zoonosis Research Institute of Zoonosis Ministry of Education Changchun P. R. China
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Quadri LEN. Biosynthesis of mycobacterial lipids by polyketide synthases and beyond. Crit Rev Biochem Mol Biol 2014; 49:179-211. [DOI: 10.3109/10409238.2014.896859] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Analysis of genes for succinoyl trehalose lipid production and increasing production in Rhodococcus sp. strain SD-74. Appl Environ Microbiol 2013; 79:7082-90. [PMID: 24038682 DOI: 10.1128/aem.01664-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Succinoyl trehalose lipids (STLs) are promising glycolipid biosurfactants produced from n-alkanes that are secreted by Rhodococcus species bacteria. These compounds not only exhibit unique interfacial properties but also demonstrate versatile biochemical actions. In this study, three novel types of genes involved in the biosynthesis of STLs, including a putative acyl coenzyme A (acyl-CoA) transferase (tlsA), fructose-bisphosphate aldolase (fda), and alkane monooxygenase (alkB), were identified. The predicted functions of these genes indicate that alkane metabolism, sugar synthesis, and the addition of acyl groups are important for the biosynthesis of STLs. Based on these results, we propose a biosynthesis pathway for STLs from alkanes in Rhodococcus sp. strain SD-74. By overexpressing tlsA, we achieved a 2-fold increase in the production of STLs. This study advances our understanding of bacterial glycolipid production in Rhodococcus species.
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Abstract
Long-chain-length hydrophobic acyl residues play a vital role in a multitude of essential biological structures and processes. They build the inner hydrophobic layers of biological membranes, are converted to intracellular storage compounds, and are used to modify protein properties or function as membrane anchors, to name only a few functions. Acyl thioesters are transferred by acyltransferases or transacylases to a variety of different substrates or are polymerized to lipophilic storage compounds. Lipases represent another important enzyme class dealing with fatty acyl chains; however, they cannot be regarded as acyltransferases in the strict sense. This review provides a detailed survey of the wide spectrum of bacterial acyltransferases and compares different enzyme families in regard to their catalytic mechanisms. On the basis of their studied or assumed mechanisms, most of the acyl-transferring enzymes can be divided into two groups. The majority of enzymes discussed in this review employ a conserved acyltransferase motif with an invariant histidine residue, followed by an acidic amino acid residue, and their catalytic mechanism is characterized by a noncovalent transition state. In contrast to that, lipases rely on completely different mechanism which employs a catalytic triad and functions via the formation of covalent intermediates. This is, for example, similar to the mechanism which has been suggested for polyester synthases. Consequently, although the presented enzyme types neither share homology nor have a common three-dimensional structure, and although they deal with greatly varying molecule structures, this variety is not reflected in their mechanisms, all of which rely on a catalytically active histidine residue.
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Affiliation(s)
- Annika Röttig
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität, Münster, Germany
- Environmental Sciences Department, King Abdulaziz University, Jeddah, Saudi Arabia
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Weiling H, Xiaowen Y, Chunmei L, Jianping X. Function and evolution of ubiquitous bacterial signaling adapter phosphopeptide recognition domain FHA. Cell Signal 2013. [DOI: 10.1016/j.cellsig.2012.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Gómez-Velasco A, Bach H, Rana AK, Cox LR, Bhatt A, Besra GS, Av-Gay Y. Disruption of the serine/threonine protein kinase H affects phthiocerol dimycocerosates synthesis in Mycobacterium tuberculosis. MICROBIOLOGY-SGM 2013; 159:726-736. [PMID: 23412844 PMCID: PMC3709824 DOI: 10.1099/mic.0.062067-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mycobacterium tuberculosis possesses a complex cell wall that is unique and essential for interaction of the pathogen with its human host. Emerging evidence suggests that the biosynthesis of complex cell-wall lipids is mediated by serine/threonine protein kinases (STPKs). Herein, we show, using in vivo radiolabelling, MS and immunostaining analyses, that targeted deletion of one of the STPKs, pknH, attenuates the production of phthiocerol dimycocerosates (PDIMs), a major M. tuberculosis virulence lipid. Comparative protein expression analysis revealed that proteins in the PDIM biosynthetic pathway are differentially expressed in a deleted pknH strain. Furthermore, we analysed the composition of the major lipoglycans, lipoarabinomannan (LAM) and lipomannan (LM), and found a twofold higher LAM/LM ratio in the mutant strain. Thus, we provide experimental evidence that PknH contributes to the production and synthesis of M. tuberculosis cell-wall components.
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Affiliation(s)
- Anaximandro Gómez-Velasco
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Horacio Bach
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Amrita K Rana
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Liam R Cox
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Apoorva Bhatt
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Gurdyal S Besra
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Yossef Av-Gay
- Department of Medicine, Division of Infectious Diseases, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Identification of a residue affecting fatty alcohol selectivity in wax ester synthase. Appl Environ Microbiol 2012; 79:396-9. [PMID: 23087036 DOI: 10.1128/aem.02523-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The terminal enzyme in the bacterial wax ester biosynthetic pathway is the bifunctional wax ester synthase/acyl-coenzyme A:diacylglycerol acyltransferase (WS/DGAT), which utilizes a fatty alcohol and a fatty acyl-coenzyme A (CoA) to synthesize the corresponding wax ester. In this report, we identify a specific residue in WS/DGAT enzymes obtained from Marinobacter aquaeolei VT8 and Acinetobacter baylyi that alters fatty alcohol selectivity and kinetic parameters when modified to alternative residues.
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Saini V, Raghuvanshi S, Khurana JP, Ahmed N, Hasnain SE, Tyagi AK, Tyagi AK. Massive gene acquisitions in Mycobacterium indicus pranii provide a perspective on mycobacterial evolution. Nucleic Acids Res 2012; 40:10832-50. [PMID: 22965120 PMCID: PMC3505973 DOI: 10.1093/nar/gks793] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Understanding the evolutionary and genomic mechanisms responsible for turning the soil-derived saprophytic mycobacteria into lethal intracellular pathogens is a critical step towards the development of strategies for the control of mycobacterial diseases. In this context, Mycobacterium indicus pranii (MIP) is of specific interest because of its unique immunological and evolutionary significance. Evolutionarily, it is the progenitor of opportunistic pathogens belonging to M. avium complex and is endowed with features that place it between saprophytic and pathogenic species. Herein, we have sequenced the complete MIP genome to understand its unique life style, basis of immunomodulation and habitat diversification in mycobacteria. As a case of massive gene acquisitions, 50.5% of MIP open reading frames (ORFs) are laterally acquired. We show, for the first time for Mycobacterium, that MIP genome has mosaic architecture. These gene acquisitions have led to the enrichment of selected gene families critical to MIP physiology. Comparative genomic analysis indicates a higher antigenic potential of MIP imparting it a unique ability for immunomodulation. Besides, it also suggests an important role of genomic fluidity in habitat diversification within mycobacteria and provides a unique view of evolutionary divergence and putative bottlenecks that might have eventually led to intracellular survival and pathogenic attributes in mycobacteria.
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Affiliation(s)
- Vikram Saini
- Department of Biochemistry, University of Delhi South Campus, New Delhi 110021, India
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Favrot L, Ronning DR. Targeting the mycobacterial envelope for tuberculosis drug development. Expert Rev Anti Infect Ther 2012; 10:1023-36. [PMID: 23106277 PMCID: PMC3571691 DOI: 10.1586/eri.12.91] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The bacterium that causes tuberculosis, Mycobacterium tuberculosis, possesses a rather unique outer membrane composed largely of lipids that possess long-chain and branched fatty acids, called mycolic acids. These lipids form a permeability barrier that prevents entry of many environmental solutes, thereby making these bacteria acid-fast and able to survive extremely hostile surroundings. Antitubercular drugs must penetrate this layer to reach their target. This review highlights drug development efforts that have added to the slowly growing tuberculosis drug pipeline, identified new enzyme activities to target with drugs and increased the understanding of important biosynthetic pathways for mycobacterial outer membrane and cell wall core assembly. In addition, a portion of this review looks at discovery efforts aimed at weakening this barrier to decrease mycobacterial virulence, decrease fitness in the host or enhance the efficacy of the current drug repertoire by disrupting the permeability barrier.
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Affiliation(s)
- Lorenza Favrot
- Department of Chemistry, University of Toledo, Toledo, OH 43606, USA
| | - Donald R Ronning
- Department of Chemistry, University of Toledo, Toledo, OH 43606, USA
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Manjasetty BA, Yu XH, Panjikar S, Taguchi G, Chance MR, Liu CJ. Structural basis for modification of flavonol and naphthol glucoconjugates by Nicotiana tabacum malonyltransferase (NtMaT1). PLANTA 2012; 236:781-93. [PMID: 22610270 DOI: 10.1007/s00425-012-1660-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 04/23/2012] [Indexed: 06/01/2023]
Abstract
Plant HXXXD acyltransferase-catalyzed malonylation is an important modification reaction in elaborating the structural diversity of flavonoids and anthocyanins, and a universal adaptive mechanism to detoxify xenobiotics. Nicotiana tabacum malonyltransferase 1 (NtMaT1) is a member of anthocyanin acyltransferase subfamily that uses malonyl-CoA (MLC) as donor catalyzing transacylation in a range of flavonoid and naphthol glucosides. To gain insights into the molecular basis underlying its catalytic mechanism and versatile substrate specificity, we resolved the X-ray crystal structure of NtMaT1 to 3.1 Å resolution. The structure comprises two α/β mixed subdomains, as typically found in the HXXXD acyltransferases. The partial electron density map of malonyl-CoA allowed us to reliably dock the entire molecule into the solvent channel and subsequently define the binding sites for both donor and acceptor substrates. MLC bound to the NtMaT1 occupies one end of the long solvent channel between two subdomains. On superimposing and comparing the structure of NtMaT1 with that of an enzyme from anthocyanin acyltransferase subfamily from red chrysanthemum (Dm3Mat3) revealed large architectural variation in the binding sites, both for the acyl donor and for the acceptor, although their overall protein folds are structurally conserved. Consequently, the shape and the interactions of malonyl-CoA with the binding sites' amino acid residues differ substantially. These major local architectural disparities point to the independent, divergent evolution of plant HXXXD acyltransferases in different species. The structural flexibility of the enzyme and the amendable binding pattern of the substrates provide a basis for the evolution of the distinct, versatile substrate specificity of plant HXXXD acyltransferases.
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Affiliation(s)
- Babu A Manjasetty
- European Molecular Biology Laboratory, Grenoble Outstation and Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS, UMI 3265, 6 Rue Jules Horowitz, 38042, Grenoble Cedex 9, France
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Tatham E, Sundaram Chavadi S, Mohandas P, Edupuganti UR, Angala SK, Chatterjee D, Quadri LEN. Production of mycobacterial cell wall glycopeptidolipids requires a member of the MbtH-like protein family. BMC Microbiol 2012; 12:118. [PMID: 22726990 PMCID: PMC3537567 DOI: 10.1186/1471-2180-12-118] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 05/07/2012] [Indexed: 12/22/2022] Open
Abstract
Background Glycopeptidolipids (GPLs) are among the major free glycolipid components of the outer membrane of several saprophytic and clinically-relevant Mycobacterium species. The architecture of GPLs is based on a constant tripeptide-amino alcohol core of nonribosomal peptide synthetase origin that is N-acylated with a 3-hydroxy/methoxy acyl chain synthesized by a polyketide synthase and further decorated with variable glycosylation patterns built from methylated and acetylated sugars. GPLs have been implicated in many aspects of mycobacterial biology, thus highlighting the significance of gaining an understanding of their biosynthesis. Our bioinformatics analysis revealed that every GPL biosynthetic gene cluster known to date contains a gene (referred herein to as gplH) encoding a member of the MbtH-like protein family. Herein, we sought to conclusively establish whether gplH was required for GPL production. Results Deletion of gplH, a gene clustered with nonribosomal peptide synthetase-encoding genes in the GPL biosynthetic gene cluster of Mycobacterium smegmatis, produced a GPL deficient mutant. Transformation of this mutant with a plasmid expressing gplH restored GPL production. Complementation was also achieved by plasmid-based constitutive expression of mbtH, a paralog of gplH found in the biosynthetic gene cluster for production of the siderophore mycobactin of M. smegmatis. Further characterization of the gplH mutant indicated that it also displayed atypical colony morphology, lack of sliding motility, altered capacity for biofilm formation, and increased drug susceptibility. Conclusions Herein, we provide evidence formally establishing that gplH is essential for GPL production in M. smegmatis. Inactivation of gplH also leads to a pleiotropic phenotype likely to arise from alterations in the cell envelope due to the lack of GPLs. While genes encoding MbtH-like proteins have been shown to be needed for production of siderophores and antibiotics, our study presents the first case of one such gene proven to be required for production of a cell wall component. Furthermore, our results provide the first example of a mbtH-like gene with confirmed functional role in a member of the Mycobacterium genus. Altogether, our findings demonstrate a critical role of gplH in mycobacterial biology and advance our understanding of the genetic requirements for the biosynthesis of an important group of constituents of the mycobacterial outer membrane.
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Affiliation(s)
- Elizabeth Tatham
- Department of Biology, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
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Chavadi SS, Onwueme KC, Edupuganti UR, Jerome J, Chatterjee D, Soll CE, Quadri LEN. The mycobacterial acyltransferase PapA5 is required for biosynthesis of cell wall-associated phenolic glycolipids. MICROBIOLOGY-SGM 2012; 158:1379-1387. [PMID: 22361940 DOI: 10.1099/mic.0.057869-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Phenolic glycolipids (PGLs) are non-covalently bound components of the outer membrane of many clinically relevant mycobacterial pathogens, and play important roles in pathogen biology. We report a mutational analysis that conclusively demonstrates that the conserved acyltransferase-encoding gene papA5 is essential for PGL production. In addition, we provide an in vitro acyltransferase activity analysis that establishes proof of principle for the competency of PapA5 to utilize diol-containing polyketide compounds of mycobacterial origin as acyl-acceptor substrates. Overall, the results reported herein are in line with a model in which PapA5 catalyses the acylation of diol-containing polyketides to form PGLs. These studies advance our understanding of the biosynthesis of an important group of mycobacterial glycolipids and suggest that PapA5 might be an attractive target for exploring the development of antivirulence drugs.
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Affiliation(s)
| | - Kenolisa C Onwueme
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, NY 10021, USA
| | | | - Jeff Jerome
- Department of Biology, Brooklyn College - City University of New York, Brooklyn, NY 11210, USA
| | - Delphi Chatterjee
- Microbiology, Immunology and Pathology Department, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Clifford E Soll
- Chemistry Department, Hunter College - City University of New York, NY 10065, USA
| | - Luis E N Quadri
- Department of Biology, Brooklyn College - City University of New York, Brooklyn, NY 11210, USA
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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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Abstract
The mycobactin siderophore system is present in many Mycobacterium species, including M. tuberculosis and other clinically relevant mycobacteria. This siderophore system is believed to be utilized by both pathogenic and nonpathogenic mycobacteria for iron acquisition in both in vivo and ex vivo iron-limiting environments, respectively. Several M. tuberculosis genes located in a so-called mbt gene cluster have been predicted to be required for the biosynthesis of the core scaffold of mycobactin based on sequence analysis. A systematic and controlled mutational analysis probing the hypothesized essential nature of each of these genes for mycobactin production has been lacking. The degree of conservation of mbt gene cluster orthologs remains to be investigated as well. In this study, we sought to conclusively establish whether each of nine mbt genes was required for mycobactin production and to examine the conservation of gene clusters orthologous to the M. tuberculosis mbt gene cluster in other bacteria. We report a systematic mutational analysis of the mbt gene cluster ortholog found in Mycobacterium smegmatis. This mutational analysis demonstrates that eight of the nine mbt genes investigated are essential for mycobactin production. Our genome mining and phylogenetic analyses reveal the presence of orthologous mbt gene clusters in several bacterial species. These gene clusters display significant organizational differences originating from an intricate evolutionary path that might have included horizontal gene transfers. Altogether, the findings reported herein advance our understanding of the genetic requirements for the biosynthesis of an important mycobacterial secondary metabolite with relevance to virulence.
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Rombouts Y, Alibaud L, Carrère-Kremer S, Maes E, Tokarski C, Elass E, Kremer L, Guérardel Y. Fatty acyl chains of Mycobacterium marinum lipooligosaccharides: structure, localization and acylation by PapA4 (MMAR_2343) protein. J Biol Chem 2011; 286:33678-88. [PMID: 21803773 DOI: 10.1074/jbc.m111.273920] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have recently established the fine structure of the glycan backbone of lipooligosaccharides (LOS-I to LOS-IV) isolated from Mycobacterium marinum, a close relative of Mycobacterium tuberculosis. These studies culminated with the description of an unusual terminal N-acylated monosaccharide that confers important biological functions to LOS-IV, such as macrophage activation, that may be relevant to granuloma formation. It was, however, also suggested that the lipid moiety was required for LOSs to exert their immunomodulatory activity. Herein, using highly purified LOSs from M. marinum, we have determined through a combination of mass spectrometric and NMR techniques, the structure and localization of the fatty acids composing the lipid moiety. The occurrence of two distinct polymethyl-branched fatty acids presenting specific localizations is consistent with the presence of two highly related polyketide synthases (Pks5 and Pks5.1) in M. marinum and presumably involved in the synthesis of these fatty acyl chains. In addition, a bioinformatic search permitted us to identify a set of enzymes potentially involved in the biosynthesis or transfer of these lipids to the LOS trehalose unit. These include MMAR_2343, a member of the Pap (polyketide-associated protein) family, that acylates trehalose-based glycolipids in M. marinum. The participation of MMAR_2343 to LOS assembly was demonstrated using a M. marinum mutant carrying a transposon insertion in the MMAR_2343 gene. Disruption of MMAR_2343 resulted in a severe LOS breakdown, indicating that MMAR_2343, hereafter designated PapA4, fulfills the requirements for LOS acylation and assembly.
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Affiliation(s)
- Yoann Rombouts
- Université de Lille 1, Unité de Glycobiologie Structurale et Fonctionnelle, F-59650 Villeneuve d'Ascq, France
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Chavadi SS, Edupuganti UR, Vergnolle O, Fatima I, Singh SM, Soll CE, Quadri LEN. Inactivation of tesA reduces cell wall lipid production and increases drug susceptibility in mycobacteria. J Biol Chem 2011; 286:24616-25. [PMID: 21592957 DOI: 10.1074/jbc.m111.247601] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phthiocerol dimycocerosates (PDIMs) and phenolic glycolipids (PGLs) are structurally related lipids noncovalently bound to the outer cell wall layer of Mycobacterium tuberculosis, Mycobacterium leprae, and several opportunistic mycobacterial human pathogens. PDIMs and PGLs are important effectors of virulence. Elucidation of the biosynthesis of these complex lipids will not only expand our understanding of mycobacterial cell wall biosynthesis, but it may also illuminate potential routes to novel therapeutics against mycobacterial infections. We report the construction of an in-frame deletion mutant of tesA (encoding a type II thioesterase) in the opportunistic human pathogen Mycobacterium marinum and the characterization of this mutant and its corresponding complemented strain control in terms of PDIM and PGL production. The growth and antibiotic susceptibility of these strains were also probed and compared with the parental wild-type strain. We show that deletion of tesA leads to a mutant that produces only traces of PDIMs and PGLs, has a slight growth yield increase and displays a substantial hypersusceptibility to several antibiotics. We also provide a robust model for the three-dimensional structure of M. marinum TesA (TesAmm) and demonstrate that a Ser-to-Ala substitution in the predicted catalytic Ser of TesAmm renders a mutant that recapitulates the phenotype of the tesA deletion mutant. Overall, our studies demonstrate a critical role for tesA in mycobacterial biology, advance our understanding of the biosynthesis of an important group of polyketide synthase-derived mycobacterial lipids, and suggest that drugs aimed at blocking PDIM and/or PGL production might synergize with antibiotic therapy in the control of mycobacterial infections.
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Zheng J, Wei C, Zhao L, Liu L, Leng W, Li W, Jin Q. Combining blue native polyacrylamide gel electrophoresis with liquid chromatography tandem mass spectrometry as an effective strategy for analyzing potential membrane protein complexes of Mycobacterium bovis bacillus Calmette-Guérin. BMC Genomics 2011; 12:40. [PMID: 21241518 PMCID: PMC3032701 DOI: 10.1186/1471-2164-12-40] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2010] [Accepted: 01/18/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tuberculosis is an infectious bacterial disease in humans caused primarily by Mycobacterium tuberculosis, and infects one-third of the world's total population. Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccine has been widely used to prevent tuberculosis worldwide since 1921. Membrane proteins play important roles in various cellular processes, and the protein-protein interactions involved in these processes may provide further information about molecular organization and cellular pathways. However, membrane proteins are notoriously under-represented by traditional two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and little is known about mycobacterial membrane and membrane-associated protein complexes. Here we investigated M. bovis BCG by an alternative proteomic strategy coupling blue native PAGE to liquid chromatography tandem mass spectrometry (LC-MS/MS) to characterize potential protein-protein interactions in membrane fractions. RESULTS Using this approach, we analyzed native molecular composition of protein complexes in BCG membrane fractions. As a result, 40 proteins (including 12 integral membrane proteins), which were organized in 9 different gel bands, were unambiguous identified. The proteins identified have been experimentally confirmed using 2-D SDS PAGE. We identified MmpL8 and four neighboring proteins that were involved in lipid transport complexes, and all subunits of ATP synthase complex in their monomeric states. Two phenolpthiocerol synthases and three arabinosyltransferases belonging to individual operons were obtained in different gel bands. Furthermore, two giant multifunctional enzymes, Pks7 and Pks8, and four mycobacterial Hsp family members were determined. Additionally, seven ribosomal proteins involved in polyribosome complex and two subunits of the succinate dehydrogenase complex were also found. Notablely, some proteins with high hydrophobicity or multiple transmembrane helixes were identified well in our work. CONCLUSIONS In this study, we utilized LC-MS/MS in combination with blue native PAGE to characterize modular components of multiprotein complexes in BCG membrane fractions. The results demonstrated that the proteomic strategy was a reliable and reproducible tool for analysis of BCG multiprotein complexes. The identification in our study may provide some evidence for further study of BCG protein interaction.
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Affiliation(s)
- Jianhua Zheng
- State Key Laboratory for Molecular Virology and Genetic Engineering, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, PR China
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Kendall SL, Frita R. Construction of targeted mycobacterial mutants by homologous recombination. Methods Mol Biol 2010; 465:297-310. [PMID: 20560068 DOI: 10.1007/978-1-59745-207-6_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The ability to select genes to knock out of mycobacterial genomes has greatly improved our understanding of mycobacteria. This chapter describes a method for doing this. The gene (including a 1-kb flanking region) is cloned into a pNIL series vector and disrupted by deletion or insertion of a cassette. A selection of marker genes obtained from the pGOAL series of vectors are inserted into the pNIL vector to create a suicide delivery system. This delivery vector is introduced into mycobacteria where the disrupted version of the gene replaces the wild-type version by a two-step homologous recombination process. The method involves selecting for a single crossover event followed by selection of double crossovers. Single crossovers have incorporated plasmid marker genes and are sucrose(S), kanamycin(R) and blue on media containing X-gal. Double crossovers have lost plasmid markers and are sucrose(R), kanamycin(S) and white on media containing X-gal.
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Affiliation(s)
- Sharon L Kendall
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Royal College Street, London NW1 OTU, UK.
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Balhana R, Stoker NG, Sikder MH, Chauviac FX, Kendall SL. Rapid construction of mycobacterial mutagenesis vectors using ligation-independent cloning. J Microbiol Methods 2010; 83:34-41. [PMID: 20650290 PMCID: PMC2941038 DOI: 10.1016/j.mimet.2010.07.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 07/08/2010] [Accepted: 07/12/2010] [Indexed: 10/25/2022]
Abstract
Targeted mutagenesis is one of the major tools for determining the function of a given gene and its involvement in bacterial pathogenesis. In mycobacteria, gene deletion is often accomplished by using allelic exchange techniques that commonly utilise a suicide delivery vector. We have adapted a widely-used suicide delivery vector (p1NIL) for cloning two flanking regions of a gene using ligation independent cloning (LIC). The pNILRB plasmid series produced allow a faster, more efficient and less laborious cloning procedure. In this paper we describe the making of pNILRB5, a modified version of p1NIL that contains two pairs of LIC sites flanking either a sacB or a lacZ gene. We demonstrate the success of this technique by generating 3 mycobacterial mutant strains. These vectors will contribute to more high-throughput methods of mutagenesis.
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Affiliation(s)
- Ricardo Balhana
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Centre for Emerging, Endemic and Exotic Disease, Hawkshead Lane, Hertfordshire, AL9 7TA, United Kingdom
| | - Neil G. Stoker
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Centre for Emerging, Endemic and Exotic Disease, Hawkshead Lane, Hertfordshire, AL9 7TA, United Kingdom
| | - Mahmudul Hasan Sikder
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Centre for Emerging, Endemic and Exotic Disease, Hawkshead Lane, Hertfordshire, AL9 7TA, United Kingdom
| | | | - Sharon L. Kendall
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Centre for Emerging, Endemic and Exotic Disease, Hawkshead Lane, Hertfordshire, AL9 7TA, United Kingdom
- Corresponding author. Tel.: +44 1707 666333x7058.
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He W, Soll CE, Chavadi SS, Zhang G, Warren JD, Quadri LEN. Cooperation between a coenzyme A-independent stand-alone initiation module and an iterative type I polyketide synthase during synthesis of mycobacterial phenolic glycolipids. J Am Chem Soc 2010; 131:16744-50. [PMID: 19799378 PMCID: PMC2779066 DOI: 10.1021/ja904792q] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
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Several Mycobacterium tuberculosis strains, Mycobacterium leprae, and other mycobacterial pathogens produce a group of small-molecule virulence factors called phenolic glycolipids (PGLs). PGLs play key roles in pathogenicity and host−pathogen interaction. Thus, elucidation of the PGL biosynthetic pathway will not only expand our understanding of natural product biosynthesis, but may also illuminate routes to novel therapeutics to afford alternative lines of defense against mycobacterial infections. In this study, we report an investigation of the enzymatic requirements for the production of long-chain p-hydroxyphenylalkanoate intermediates of PGL biosynthesis. We demonstrate a functional cooperation between a coenzyme A-independent stand-alone didomain initiation module (FadD22) and a 6-domain reducing iterative type I polyketide synthase (Pks15/1) for production of p-hydroxyphenylalkanoate intermediates in in vitro and in vivo FadD22-Pks15/1 reconstituted systems. Our results suggest that Pks15/1 is an iterative type I polyketide synthase with a relaxed control of catalytic cycle iterations, a mechanistic property that explains the origin of a characteristic alkyl chain length variability seen in mycobacterial PGLs. The FadD22-Pks15/1 reconstituted systems lay an initial foundation for future efforts to unveil the mechanism of iterative catalysis control by which the structures of the final products of Pks15/1 are defined, and to scrutinize the functional partnerships of the FadD22-Pks15/1 system with downstream enzymes of the PGL biosynthetic pathway.
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Affiliation(s)
- Weiguo He
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10065, USA
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Gupta M, Sajid A, Arora G, Tandon V, Singh Y. Forkhead-associated domain-containing protein Rv0019c and polyketide-associated protein PapA5, from substrates of serine/threonine protein kinase PknB to interacting proteins of Mycobacterium tuberculosis. J Biol Chem 2009; 284:34723-34. [PMID: 19826007 DOI: 10.1074/jbc.m109.058834] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycobacterium tuberculosis profoundly exploits protein phosphorylation events carried out by serine/threonine protein kinases (STPKs) for its survival and pathogenicity. Forkhead-associated domains (FHA), the phosphorylation-responsive modules, have emerged as prominent players in STPK mediated signaling. In this study, we demonstrate the association of the previously uncharacterized FHA domain-containing protein Rv0019c with cognate STPK PknB. The consequent phosphorylation of Rv0019c is shown to be dependent on the conserved residues in the Rv0019c FHA domain and activation loop of PknB. Furthermore, by creating deletion mutants we identify Thr(36) as the primary phosphorylation site in Rv0019c. During purification of Rv0019c from Escherichia coli, the E. coli protein chloramphenicol acetyltransferase (CAT) specifically and reproducibly copurifies with Rv0019c in a FHA domain-dependent manner. On the basis of structural similarity of E. coli CAT with M. tuberculosis PapA5, a protein involved in phthiocerol dimycocerosate biosynthesis, PapA5 is identified as an interaction partner of Rv0019c. The interaction studies on PapA5, purified as an unphosphorylated protein from E. coli, with Rv0019c deletion mutants reveal that the residues N-terminal to the functional FHA domain of Rv0019c are critical for formation of the Rv0019c-PapA5 complex and thus constitute a previously unidentified phosphoindependent binding motif. Finally, PapA5 is shown to be phosphorylated on threonine residue(s) by PknB, whereas serine/threonine phosphatase Mstp completely reverses the phosphorylation. Thus, our data provides initial clues for a possible regulation of PapA5 and hence the phthiocerol dimycocerosate biosynthesis by PknB, either by direct phosphorylation of PapA5 or indirectly through Rv0019c.
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Affiliation(s)
- Meetu Gupta
- Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Delhi 110007, India
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49
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Garvey GS, McCormick SP, Alexander NJ, Rayment I. Structural and functional characterization of TRI3 trichothecene 15-O-acetyltransferase from Fusarium sporotrichioides. Protein Sci 2009; 18:747-61. [PMID: 19319932 DOI: 10.1002/pro.80] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Fusarium head blight is a devastating disease of cereal crops whose worldwide incidence is increasing and at present there is no satisfactory way of combating this pathogen or its associated toxins. There is a wide variety of trichothecene mycotoxins and they all contain a 12,13-epoxytrichothecene skeleton but differ in their substitutions. Indeed, there is considerable variation in the toxin profile across the numerous Fusarium species that has been ascribed to differences in the presence or absence of biosynthetic enzymes and their relative activity. This article addresses the source of differences in acetylation at the C15 position of the trichothecene molecule. Here, we present the in vitro structural and biochemical characterization of TRI3, a 15-O-trichothecene acetyltransferase isolated from F. sporotrichioides and the "in vivo" characterization of Deltatri3 mutants of deoxynivalenol (DON) producing F. graminearum strains. A kinetic analysis shows that TRI3 is an efficient enzyme with the native substrate, 15-decalonectrin, but is inactive with either DON or nivalenol. The structure of TRI3 complexed with 15-decalonectrin provides an explanation for this specificity and shows that Tri3 and Tri101 (3-O-trichothecene acetyltransferase) are evolutionarily related. The active site residues are conserved across all sequences for TRI3 orthologs, suggesting that differences in acetylation at C15 are not due to differences in Tri3. The tri3 deletion mutant shows that acetylation at C15 is required for DON biosynthesis even though DON lacks a C15 acetyl group. The enzyme(s) responsible for deacetylation at the 15 position of the trichothecene mycotoxins have not been identified.
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Affiliation(s)
- Graeme S Garvey
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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50
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Hatzios SK, Schelle MW, Holsclaw CM, Behrens CR, Botyanszki Z, Lin FL, Carlson BL, Kumar P, Leary JA, Bertozzi CR. PapA3 is an acyltransferase required for polyacyltrehalose biosynthesis in Mycobacterium tuberculosis. J Biol Chem 2009; 284:12745-51. [PMID: 19276083 PMCID: PMC2676004 DOI: 10.1074/jbc.m809088200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mycobacterium tuberculosis possesses an unusual cell wall that is
replete with virulence-enhancing lipids. One cell wall molecule unique to
pathogenic M. tuberculosis is polyacyltrehalose (PAT), a
pentaacylated, trehalose-based glycolipid. Little is known about the
biosynthesis of PAT, although its biosynthetic gene cluster has been
identified and found to resemble that of the better studied M.
tuberculosis cell wall component sulfolipid-1. In this study, we sought
to elucidate the function of papA3, a gene from the PAT locus
encoding a putative acyltransferase. To determine whether PapA3 participates
in PAT assembly, we expressed the protein heterologously and evaluated its
acyltransferase activity in vitro. The purified enzyme catalyzed the
sequential esterification of trehalose with two palmitoyl groups, generating a
diacylated product similar to the 2,3-diacyltrehalose glycolipids of M.
tuberculosis. Notably, PapA3 was selective for trehalose; no activity was
observed with other structurally related disaccharides. Disruption of the
papA3 gene from M. tuberculosis resulted in the loss of PAT
from bacterial lipid extracts. Complementation of the mutant strain restored
PAT production, demonstrating that PapA3 is essential for the biosynthesis of
this glycolipid in vivo. Furthermore, we determined that the PAT
biosynthetic machinery has no cross-talk with that for sulfolipid-1 despite
their related structures.
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Affiliation(s)
- Stavroula K Hatzios
- Department of Chemistry and Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA
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