Title

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

Authors

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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