title: Mycobacterium tuberculosis rv1400c encodes functional lipase/esterase.
abstract: Lipases catalyze the hydrolysis of triglycerides (TAG). Open reading frames (ORF) predicted to encode enzymes involved in fatty acids breakdown are abundant in Mycobacterium tuberculosis genome. To define the function of M. tuberculosis rv1400c (LipI), a putative Hormone Sensitive Lipase (HSL) subfamily ORF, the rv1400c was cloned, expressed and purified in Escherichia coli as fusion protein. The purified LipI preferred short carbon chain substrates with an optimal activity at 37 °C/pH 8.0 and stable between pH 6.0 to 9.0. Its specific activity was calculated to 35.71 U/mg with pNP-butyrate as a preferred substrate. SDS, CTAB and Zn2+can inhibit this enzyme. The conserved residues Ser165 and His291 were shown to be important for the catalysis activity of Rv1400c by site-directed mutagenesis. The biochemical and genetical data showed M. tuberculosis LipI might be a good candidate catalyst for polyunsaturated fatty acids.
authors.affiliation: 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, Beibei, Chongqing 400715, China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Lin
authors.affiliation: 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, Beibei, Chongqing 400715, China.
authors.forename: Qiming
authors.initials: Q
authors.lastname: Li
authors.affiliation: 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, Beibei, Chongqing 400715, China.
authors.forename: Longxiang
authors.initials: L
authors.lastname: Xie
authors.affiliation: 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, Beibei, Chongqing 400715, China. Electronic address: georgex@swu.edu.cn.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xie
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D002384:Catalysis; D003001:Cloning, Molecular; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D009169:Mycobacterium tuberculosis / Q000201:enzymology / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D002787:Sterol Esterase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D005231:Fatty Acids, Unsaturated; D011993:Recombinant Fusion Proteins; D002787:Sterol Esterase
keywords: Esterase/lipase; LipI; Mycobacterium tuberculosis; Persistence; rv1400c