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Liu X, Jiang Y, Zhang Y, Yu M, Jiang H, Xu J, Shi J. FgIlv3a is crucial in branched-chain amino acid biosynthesis, vegetative differentiation, and virulence in Fusarium graminearum. J Microbiol 2019; 57:694-703. [PMID: 31079334 DOI: 10.1007/s12275-019-9123-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 12/22/2022]
Abstract
Dihydroxyacid dehydratase (DHAD), encoded by ILV3, catalyses the third step in the biosynthetic pathway of branched-chain amino acids (BCAAs), which include isoleucine (Ile), leucine (Leu), and valine (Val). Enzymes involved in BCAA biosynthesis exist in bacteria, plants, and fungi but not in mammals and are therefore attractive targets for antimicrobial or herbicide development. In this study, three paralogous ILV3 genes (FgILV3A, FgILV3B, and FgILV3C) were identified in the genome of Fusarium graminearum, the causal agent of Fusarium head blight (FHB). Deletion of FgILV3A alone or combined with FgILV3B or FgILV3C indicated an important role for FgILV3A in BCAA biosynthesis. FgILV3A deletion mutants lost the ability to grow on medium lacking amino acids. Exogenous supplementation of 1 mM Ile and Val rescued the auxotrophy of ΔFgIlv3A, though 5 mM was required to recover the growth defects in ΔFgIlv3AB and ΔFgIlv3AC strains, indicating that FgIlv3b and FgIlv3c exhibit redundant but accessory roles with FgIlv3a in BCAA biosynthesis. The auxotrophy of ΔFgIlv3A resulted in pleiotropic defects in aerial hyphal growth, in conidial formation and germination, and in aurofusarin accumulation. In addition, the mutants showed reduced virulence and deoxynivalenol production. Overall, our study demonstrates that FgIlv3a is crucial for BCAA biosynthesis in F. graminearum and a candidate fungicide target for FHB management.
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Affiliation(s)
- Xin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China.,School of Food and Biological Engineering, Jiangsu Univeristy, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Yichen Jiang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China.,College of Food Science, Tibet Agriculture and Animal Husbandry University, Linzhi, 860000, Tibet, P. R. China
| | - Yinghui Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China.,College of Life Science, Sanquan College of Xinxiang Medical University, Xinxiang, 453003, Henan, P. R. China
| | - Mingzheng Yu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China
| | - Hongjun Jiang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China.,College of Plant Protection, Nanjing Agriculture University, Nanjing, 210095, Jiangsu, P. R. China
| | - Jianhong Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China.,School of Food and Biological Engineering, Jiangsu Univeristy, Zhenjiang, 212013, Jiangsu, P. R. China
| | - Jianrong Shi
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture and Rural Affairs/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, P. R. China. .,School of Food and Biological Engineering, Jiangsu Univeristy, Zhenjiang, 212013, Jiangsu, P. R. China.
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Serer MI, Carrica MDC, Trappe J, López Romero S, Bonomi HR, Klinke S, Cerutti ML, Goldbaum FA. A high-throughput screening for inhibitors of riboflavin synthase identifies novel antimicrobial compounds to treat brucellosis. FEBS J 2019; 286:2522-2535. [PMID: 30927485 DOI: 10.1111/febs.14829] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/26/2019] [Accepted: 03/29/2019] [Indexed: 10/27/2022]
Abstract
Brucella spp. are pathogenic intracellular Gram-negative bacteria adapted to life within cells of several mammals, including humans. These bacteria are the causative agent of brucellosis, one of the zoonotic infections with the highest incidence in the world and for which a human vaccine is still unavailable. Current therapeutic treatments against brucellosis are based on the combination of two or more antibiotics for prolonged periods, which may lead to antibiotic resistance in the population. Riboflavin (vitamin B2) is biosynthesized by microorganisms and plants but mammals, including humans, must obtain it from dietary sources. Owing to the absence of the riboflavin biosynthetic enzymes in animals, this pathway is nowadays regarded as a rich resource of targets for the development of new antimicrobial agents. In this work, we describe a high-throughput screening approach to identify inhibitors of the enzymatic activity of riboflavin synthase, the last enzyme in this pathway. We also provide evidence for their subsequent validation as potential drug candidates in an in vitro brucellosis infection model. From an initial set of 44 000 highly diverse low molecular weight compounds with drug-like properties, we were able to identify ten molecules with 50% inhibitory concentrations in the low micromolar range. Further Brucella culture and intramacrophagic replication experiments showed that the most effective bactericidal compounds share a 2-Phenylamidazo[2,1-b][1,3]benzothiazole chemical scaffold. Altogether, these findings set up the basis for the subsequent lead optimization process and represent a promising advancement in the pursuit of novel and effective antimicrobial compounds against brucellosis.
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Affiliation(s)
- María Inés Serer
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina
| | | | - Jörg Trappe
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | | | - Sebastián Klinke
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.,Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - María Laura Cerutti
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.,Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Fernando Alberto Goldbaum
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.,Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
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Qu RY, Yang JF, Devendar P, Kang WM, Liu YC, Chen Q, Niu CW, Xi Z, Yang GF. Discovery of New 2-[(4,6-Dimethoxy-1,3,5-triazin-2-yl)oxy]-6-(substituted phenoxy)benzoic Acids as Flexible Inhibitors of Arabidopsis thaliana Acetohydroxyacid Synthase and Its P197L Mutant. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:11170-11178. [PMID: 29186952 DOI: 10.1021/acs.jafc.7b05198] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In the search for new antiresistance acetohydroxyacid synthase (AHAS, EC 2.2.1.6) inhibitors to combat weed resistance associated with AHAS mutations, a series of 2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)oxy]-6-(substituted phenoxy)benzoic acids 11-38 were designed and synthesized via the strategy of conformational flexibility analysis. Compounds 21, 22, 26, 33, 36, and 38 with high potency against both wild-type AtAHAS and its P197L mutant were identified as promising candidates with low resistance factors (RF, defined as the ratio between the ki values toward P197L mutant and wild-type AHAS) ranging from 0.73 to 6.32. Especially, compound 22 (RF = 0.73) was further identified as the most potent antiresistance AHAS inhibitor because of its significantly reduced resistance level compared with that of tribenuron-methyl (RF = 2650) and bispyribac (RF = 4.57). Furthermore, compounds 26, 33, 36, and 38 also displayed promising herbicidal activities against sensitive and resistant (P197L) Descurainia sophia at the dosage of 75-150 g of active ingredient (ai)/ha. Notably, compounds 33 and 38 still maintained over 60% herbicidal activity toward the resistant weed even at much lower dosages (37.5 g ai/ha). Therefore, the designed scaffold has the great potential to discover new candidate compounds for the control of weed resistance associated with AHAS mutation.
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Affiliation(s)
- Ren-Yu Qu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Jing-Fang Yang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Ponnam Devendar
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Wei-Ming Kang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Yu-Chao Liu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Qiong Chen
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
| | - Cong-Wei Niu
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University (NKU) , Tianjin 300071, PR China
| | - Zhen Xi
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University (NKU) , Tianjin 300071, PR China
- Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 30071, PR China
| | - Guang-Fu Yang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University (CCNU) , Wuhan 430079, PR China
- Collaborative Innovation Center of Chemical Science and Engineering , Tianjin 30071, PR China
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Jung IP, Ha NR, Lee SC, Ryoo SW, Yoon MY. Development of potent chemical antituberculosis agents targeting Mycobacterium tuberculosis acetohydroxyacid synthase. Int J Antimicrob Agents 2016; 48:247-58. [DOI: 10.1016/j.ijantimicag.2016.04.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 04/27/2016] [Accepted: 04/30/2016] [Indexed: 10/21/2022]
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5
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Synthesis and evaluation of novel N-(4′-arylpyrimidin-2′-yl) sulfonylurea derivatives as potential antifungal agents. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-4362-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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6
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Bacterial and plant ketol-acid reductoisomerases have different mechanisms of induced fit during the catalytic cycle. J Mol Biol 2012; 424:168-79. [PMID: 23036858 DOI: 10.1016/j.jmb.2012.09.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 09/09/2012] [Accepted: 09/24/2012] [Indexed: 11/21/2022]
Abstract
Ketol-acid reductoisomerase (KARI) is the second enzyme in the branched-chain amino acid biosynthesis pathway, which is found in plants, fungi and bacteria but not in animals. This difference in metabolism between animals and microorganisms makes KARI an attractive target for the development of antimicrobial agents. Herein we report the crystal structure of Escherichia coli KARI in complex with Mg(2+) and NADPH at 2.3Å resolution. Ultracentrifugation studies confirm that the enzyme exists as a tetramer in solution, and isothermal titration calorimetry shows that the binding of Mg(2+) increases structural disorder while the binding of NADPH increases the structural rigidity of the enzyme. Comparison of the structure of the E. coli KARI-Mg(2+)-NADPH complex with that of enzyme in the absence of cofactors shows that the binding of Mg(2+) and NADPH opens the interface between the N- and C-domains, thereby allowing access for the substrates to bind: the existence of only a small opening between the domains in the crystal structure of the unliganded enzyme signifies restricted access to the active site. This observation contrasts with that in the plant enzyme, where the N-domain can rotate freely with respect to the C-domain until the binding of Mg(2+) and/or NADPH stabilizes the relative positions of these domains. Support is thereby provided for the idea that plant and bacterial KARIs have evolved different mechanisms of induced fit to prepare the active site for catalysis.
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Gedi V, Yoon MY. Bacterial acetohydroxyacid synthase and its inhibitors - a summary of their structure, biological activity and current status. FEBS J 2012; 279:946-63. [DOI: 10.1111/j.1742-4658.2012.08505.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Fuchs TM, Eisenreich W, Kern T, Dandekar T. Toward a Systemic Understanding of Listeria monocytogenes Metabolism during Infection. Front Microbiol 2012; 3:23. [PMID: 22347216 PMCID: PMC3271275 DOI: 10.3389/fmicb.2012.00023] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 01/13/2012] [Indexed: 02/03/2023] Open
Abstract
Listeria monocytogenes is a foodborne human pathogen that can cause invasive infection in susceptible animals and humans. For proliferation within hosts, this facultative intracellular pathogen uses a reservoir of specific metabolic pathways, transporter, and enzymatic functions whose expression requires the coordinated activity of a complex regulatory network. The highly adapted metabolism of L. monocytogenes strongly depends on the nutrient composition of various milieus encountered during infection. Transcriptomic and proteomic studies revealed the spatial-temporal dynamic of gene expression of this pathogen during replication within cultured cells or in vivo. Metabolic clues are the utilization of unusual C(2)- and C(3)-bodies, the metabolism of pyruvate, thiamine availability, the uptake of peptides, the acquisition or biosynthesis of certain amino acids, and the degradation of glucose-phosphate via the pentose phosphate pathway. These examples illustrate the interference of in vivo conditions with energy, carbon, and nitrogen metabolism, thus affecting listerial growth. The exploitation, analysis, and modeling of the available data sets served as a first attempt to a systemic understanding of listerial metabolism during infection. L. monocytogenes might serve as a model organism for systems biology of a Gram-positive, facultative intracellular bacterium.
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Affiliation(s)
- Thilo M. Fuchs
- Abteilung Mikrobiologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung, Technische Universität MünchenFreising, Germany
- Lehrstuhl für Mikrobielle Ökologie, Department Biowissenschaften, Wissenschaftszentrum Weihenstephan, Technische Universität MünchenFreising, Germany
| | | | - Tanja Kern
- Abteilung Mikrobiologie, Zentralinstitut für Ernährungs- und Lebensmittelforschung, Technische Universität MünchenFreising, Germany
| | - Thomas Dandekar
- Abteilung Bioinformatik, Theodor-Boveri-Institut (Biozentrum), Universität WürzburgWürzburg, Germany
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Ethanolamine utilization contributes to proliferation of Salmonella enterica serovar Typhimurium in food and in nematodes. Appl Environ Microbiol 2010; 77:281-90. [PMID: 21037291 DOI: 10.1128/aem.01403-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Only three pathogenic bacterial species, Salmonella enterica, Clostridium perfringens, and Listeria monocytogenes, are able to utilize both ethanolamine and 1,2-propanediol as a sole carbon source. Degradation of these substrates, abundant in food and the gut, depends on cobalamin, which is synthesized de novo only under anaerobic conditions. Although the eut, pdu, and cob-cbi gene clusters comprise 40 kb, the conditions under which they confer a selection advantage on these food-borne pathogens remain largely unknown. Here we used the luciferase reporter system to determine the response of the Salmonella enterica serovar Typhimurium promoters P(eutS), P(pocR), P(pduF), and P(pduA) to a set of carbon sources, to egg yolk, to whole milk, and to milk protein or fat fractions. Depending on the supplements, specific inductions up to 3 orders of magnitude were observed for P(eutS) and P(pduA), which drive the expression of most eut and pdu genes. To correlate these significant expression data with growth properties, nonpolar deletions of pocR, regulating the pdu and cob-cbi genes, and of eutR, involved in eut gene activation, were constructed in S. Typhimurium strain 14028. During exponential growth of the mutants 14028ΔpocR and 14028ΔeutR, 2- to 3-fold-reduced proliferation in milk and egg yolk was observed. Using the Caenorhabditis elegans infection model, we could also demonstrate that the proliferation of S. Typhimurium in the nematode is supported by an active ethanolamine degradation pathway. Taking these findings together, this study quantifies the differential expression of eut and pdu genes under distinct conditions and provides experimental evidence that the ethanolamine utilization pathway allows salmonellae to occupy specific metabolic niches within food environments and within their host organisms.
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Vullo D, Nishimori I, Scozzafava A, Köhler S, Winum JY, Supuran CT. Inhibition studies of a β-carbonic anhydrase from Brucella suis with a series of water soluble glycosyl sulfanilamides. Bioorg Med Chem Lett 2010; 20:2178-82. [DOI: 10.1016/j.bmcl.2010.02.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/08/2010] [Accepted: 02/08/2010] [Indexed: 11/16/2022]
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Subashchandrabose S, LeVeque RM, Wagner TK, Kirkwood RN, Kiupel M, Mulks MH. Branched-chain amino acids are required for the survival and virulence of Actinobacillus pleuropneumoniae in swine. Infect Immun 2009; 77:4925-33. [PMID: 19703979 PMCID: PMC2772520 DOI: 10.1128/iai.00671-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 07/01/2009] [Accepted: 08/17/2009] [Indexed: 11/20/2022] Open
Abstract
In Actinobacillus pleuropneumoniae, which causes porcine pleuropneumonia, ilvI was identified as an in vivo-induced (ivi) gene and encodes the enzyme acetohydroxyacid synthase (AHAS) required for branched-chain amino acid (BCAA) biosynthesis. ilvI and 7 of 32 additional ivi promoters were upregulated in vitro when grown in chemically defined medium (CDM) lacking BCAA. Based on these observations, we hypothesized that BCAA would be found at limiting concentrations in pulmonary secretions and that A. pleuropneumoniae mutants unable to synthesize BCAA would be attenuated in a porcine infection model. Quantitation of free amino acids in porcine pulmonary epithelial lining fluid showed concentrations of BCAA ranging from 8 to 30 micromol/liter, which is 10 to 17% of the concentration in plasma. The expression of both ilvI and lrp, a global regulator that is required for ilvI expression, was strongly upregulated in CDM containing concentrations of BCAA similar to those found in pulmonary secretions. Deletion-disruption mutants of ilvI and lrp were both auxotrophic for BCAA in CDM and attenuated compared to wild-type A. pleuropneumoniae in competitive index experiments in a pig infection model. Wild-type A. pleuropneumoniae grew in CDM+BCAA but not in CDM-BCAA in the presence of sulfonylurea AHAS inhibitors. These results clearly demonstrate that BCAA availability is limited in the lungs and support the hypothesis that A. pleuropneumoniae, and potentially other pulmonary pathogens, uses limitation of BCAA as a cue to regulate the expression of genes required for survival and virulence. These results further suggest a potential role for AHAS inhibitors as antimicrobial agents against pulmonary pathogens.
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Affiliation(s)
- Sargurunathan Subashchandrabose
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
| | - Rhiannon M. LeVeque
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
| | - Trevor K. Wagner
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
| | - Roy N. Kirkwood
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
| | - Matti Kiupel
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
| | - Martha H. Mulks
- Comparative Medicine and Integrative Biology Program, Department of Microbiology and Molecular Genetics, Department of Large Animal Clinical Sciences, Department of Pathobiology and Diagnostic Investigation, Center for Microbial Pathogenesis, Michigan State University, East Lansing, Michigan 48824
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Liao Y, Deng J, Zhang A, Zhou M, Hu Y, Chen H, Jin M. Immunoproteomic analysis of outer membrane proteins and extracellular proteins of Actinobacillus pleuropneumoniae JL03 serotype 3. BMC Microbiol 2009; 9:172. [PMID: 19695095 PMCID: PMC2741471 DOI: 10.1186/1471-2180-9-172] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2009] [Accepted: 08/20/2009] [Indexed: 11/18/2022] Open
Abstract
Background Actinobacillus pleuropneumoniae is the causative agent of porcine contagious pleuropneumonia, a highly contagious respiratory infection in pigs, and all the 15 serotypes are able to cause disease. Current vaccines including subunit vaccines could not provide satisfactory protection against A. pleuropneumoniae. In this study, the immunoproteomic approach was applied to the analysis of extracellular and outer membrane proteins of A. pleuropneumoniae JL03 serotype 3 for the identification of novel immunogenic proteins for A. pleuropneumoniae. Results A total of 30 immunogenic proteins were identified from outer membrane and extracellular proteins of JL03 serotype 3, of which 6 were known antigens and 24 were novel immunogenic proteins for A. pleuropneumoniae. Conclusion These data provide information about novel immunogenic proteins for A. pleuropneumoniae serotype 3, and are expected to aid in development of novel vaccines against A. pleuropneumoniae.
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Affiliation(s)
- Yonghong Liao
- College of Veterinary Medicine, Huazhong Agricultural University, Hubei, PR China.
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Awasthy D, Gaonkar S, Shandil RK, Yadav R, Bharath S, Marcel N, Subbulakshmi V, Sharma U. Inactivation of the ilvB1 gene in Mycobacterium tuberculosis leads to branched-chain amino acid auxotrophy and attenuation of virulence in mice. MICROBIOLOGY-SGM 2009; 155:2978-2987. [PMID: 19542000 DOI: 10.1099/mic.0.029884-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Acetohydroxyacid synthase (AHAS) is the first enzyme in the branched-chain amino acid biosynthesis pathway in bacteria. Bioinformatics analysis revealed that the Mycobacterium tuberculosis genome contains four genes (ilvB1, ilvB2, ilvG and ilvX) coding for the large catalytic subunit of AHAS, whereas only one gene (ilvN or ilvH) coding for the smaller regulatory subunit of this enzyme was found. In order to understand the physiological role of AHAS in survival of the organism in vitro and in vivo, we inactivated the ilvB1 gene of M. tuberculosis. The mutant strain was found to be auxotrophic for all of the three branched-chain amino acids (isoleucine, leucine and valine), when grown with either C(6) or C(2) carbon sources, suggesting that the ilvB1 gene product is the major AHAS in M. tuberculosis. Depletion of these branched chain amino acids in the medium led to loss of viability of the DeltailvB1 strain in vitro, resulting in a 4-log reduction in colony-forming units after 10 days. Survival kinetics of the mutant strain cultured in macrophages maintained with sub-optimal concentrations of the branched-chain amino acids did not show any loss of viability, indicating either that the intracellular environment was rich in these amino acids or that the other AHAS catalytic subunits were functional under these conditions. Furthermore, the growth kinetics of the DeltailvB1 strain in mice indicated that although this mutant strain showed defective growth in vivo, it could persist in the infected mice for a long time, and therefore could be a potential vaccine candidate.
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Affiliation(s)
- Disha Awasthy
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
| | | | - R K Shandil
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
| | - Reena Yadav
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
| | - Sowmya Bharath
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
| | - Nimi Marcel
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
| | | | - Umender Sharma
- AstraZeneca R&D, Bellary Road, Hebbal, Bangalore-560024, India
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Xiong Y, Liu J, Yang GF, Zhan CG. Computational determination of fundamental pathway and activation barriers for acetohydroxyacid synthase-catalyzed condensation reactions of α-keto acids. J Comput Chem 2009; 31:1592-602. [DOI: 10.1002/jcc.21356] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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In vitro and ex vivo activity of new derivatives of acetohydroxyacid synthase inhibitors against Mycobacterium tuberculosis and non-tuberculous mycobacteria. Int J Antimicrob Agents 2008; 31:567-71. [DOI: 10.1016/j.ijantimicag.2008.01.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 01/09/2008] [Accepted: 01/14/2008] [Indexed: 11/20/2022]
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Brucella: A pathogen without classic virulence genes. Vet Microbiol 2008; 129:1-14. [DOI: 10.1016/j.vetmic.2007.11.023] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2006] [Revised: 11/19/2007] [Accepted: 11/22/2007] [Indexed: 01/18/2023]
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Choi KJ, Noh KM, Kim DE, Ha BH, Kim EE, Yoon MY. Identification of the catalytic subunit of acetohydroxyacid synthase in Haemophilus influenzae and its potent inhibitors. Arch Biochem Biophys 2007; 466:24-30. [PMID: 17718999 DOI: 10.1016/j.abb.2007.07.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 07/07/2007] [Accepted: 07/11/2007] [Indexed: 11/22/2022]
Abstract
Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is a thiamin diphosphate- (ThDP)- and FAD-dependent enzyme that catalyzes the first common step in the biosynthetic pathway of the branched-amino acids (BCAAs) leucine, isoleucine, and valine. The gene from Haemophilus influenzae that encodes the AHAS catalytic subunit was cloned, overexpressed in Escherichia coli BL21(DE3), and purified to homogeneity. The purified H. influenzae AHAS catalytic subunit (Hin-AHAS) appeared as a single band on SDS-PAGE gel, with a molecular mass of approximately 63 kDa. The enzyme catalyzes the condensation of two molecules of pyruvate to form acetolactate, with a K(m) of 9.2mM and the specific activity of 1.5 micromol/min/mg. The cofactor activation constant (K(c)=13.5 microM) and the dissociation constant (K(d)=3.3 microM) of ThDP were also determined by enzymatic assay and tryptophan fluorescence quenching studies, respectively. We screened a chemical library to discover new inhibitors of the Hin AHAS catalytic subunit. Through which, AVS-2087 (IC(50)=0.53 microM), KSW30191 (IC(50)=1.42 microM), and KHG20612 (IC(50)=4.91 microM) displayed potent inhibition as compare to sulfometuron methyl (IC(50)=276.31 microM).
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Affiliation(s)
- Kyoung-Jae Choi
- Department of Chemistry, Hanyang University, 17 Haedang-dong, Sungdong-gu, Seoul 133-791, Republic of Korea
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Joseph P, Abdo MR, Boigegrain RA, Montero JL, Winum JY, Köhler S. Targeting of the Brucella suis virulence factor histidinol dehydrogenase by histidinol analogues results in inhibition of intramacrophagic multiplication of the pathogen. Antimicrob Agents Chemother 2007; 51:3752-5. [PMID: 17698620 PMCID: PMC2043266 DOI: 10.1128/aac.00572-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Brucella suis histidinol dehydrogenase (HDH) can be efficiently targeted by substrate analogues. The growth of this pathogen in minimal medium was inhibited and the multiplication in human macrophages was totally abolished in the presence of the drugs. These effects have been shown to be correlated with the previously described inhibition of Brucella HDH activity.
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Affiliation(s)
- Pascale Joseph
- Centre d'Etudes d'Agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS-UM1-UM2, UMR 5236, Université Montpellier II, cc100, Place Eugène Bataillon, 34095, Montpellier Cedex, France.
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Virtual Screening of Tubercular Acetohydroxy Acid Synthase Inhibitors through Analysis of Structural Models. B KOREAN CHEM SOC 2007. [DOI: 10.5012/bkcs.2007.28.6.947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Liautard JP, Jubier-Maurin V, Boigegrain RA, Köhler S. Antimicrobials: targeting virulence genes necessary for intracellular multiplication. Trends Microbiol 2006; 14:109-13. [PMID: 16469497 DOI: 10.1016/j.tim.2006.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 01/10/2006] [Accepted: 01/20/2006] [Indexed: 10/25/2022]
Abstract
Intracellular bacteria constitute a major class of pathogens for humans and animals. Their pathogenicity is linked to their ability to multiply inside a host cell. A set of virulence genes (virulome) is required for this intracellular lifestyle. Recent studies have shown that blocking the enzymes encoded by these virulence genes impairs intracellular multiplication of the pathogen. These specific factors could constitute a new set of possible targets for antimicrobial drugs. The potential advantages, pitfalls and challenges of a strategy that targets these virulence factors are discussed.
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