Expression and characterization of Rv0447c product, potentially the methyltransferase involved in tuberculostearic acid biosynthesis in Mycobacterium tuberculosis

    Authors

    L. S. Meena;P. E. Kolattukudy

    Comments

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    Abbreviated Journal Title

    Biotechnol. Appl. Biochem.

    Keywords

    Mycobacterium tuberculosis; methyltransferase; tuberculostearic acid; oleic-acid; fatty-acid; S-adenosyl-l-methionine; MYCOLIC ACIDS; COMMON MECHANISM; DIAGNOSIS; VIRULENCE; H(37)RV; ISOXYL; PHLEI; Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology

    Abstract

    In this study, a previously uncharacterized gene (Rv0447c) of Mycobacterium tuberculosis, designated as an unknown fatty-acid methyltransferase (ufaA1), was cloned, expressed in Escherichia coli, and purified. The biochemical characterization of the purified protein (UfaA1) showed it to be a methyltransferase that catalyzes biosynthesis of the tuberculostearic acid (10-methylstearic-acid, TSA), a significant constituent lipid of the mycobacterial cell wall and a clinical marker of the disease. Here, we show that UfaA1 transfers the methyl group from S-adenosyl-l-methionine (SAM) to the double bond of oleic acid in phosphatidylethanolamine or phosphatidylcholine to produce TSA. Optimal activity was obtained between pH 7.0 and pH 8.0. The methyltransferase activity of UfaA1 was severely inhibited by S-adenosyl-l-homocysteine. The K-m values for dioleyl phosphatidylethanolamine, SAM, and nicotinamide adenine dinucleotide phosphate were 14, 13, and 83 mu M, respectively, with V-max of 1.3-1.6nmol/Min. These results identify the Rv0447c gene product of M. tuberculosis as the methyltransferase that catalyzes the biosynthesis of TSA. This provides new information in mycobacterial cell wall synthesis.

    Journal Title

    Biotechnology and Applied Biochemistry

    Volume

    60

    Issue/Number

    4

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    412

    Last Page

    416

    WOS Identifier

    WOS:000323378600006

    ISSN

    0885-4513

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