Redundant function of cmaA2 and mmaA2 in Mycobacterium tuberculosis cis cyclopropanation of oxygenated mycolates Journal Article


Authors: Barkan, D.; Rao, V.; Sukenick, G. D.; Glickman, M. S.
Article Title: Redundant function of cmaA2 and mmaA2 in Mycobacterium tuberculosis cis cyclopropanation of oxygenated mycolates
Abstract: The Mycobacterium tuberculosis cell envelope contains a wide variety of lipids and glycolipids, including mycolic acids, long-chain branched fatty acids that are decorated by cyclopropane rings. Genetic analysis of the mycolate methyltransferase family has been a powerful approach to assign functions to each of these enzymes but has failed to reveal the origin of cis cyclopropanation of the oxygenated mycolates. Here we examine potential redundancy between mycolic acid methyltransferases by generating and analyzing M. tuberculosis strains lacking mmaA2 and cmaA2, mmaA2 and cmaA1, or mmaA1 alone. M. tuberculosis lacking both cmaA2 and mmaA2 cannot cis cyclopropanate methoxymycolates or ketomycolates, phenotypes not shared by the mmaA2 and cmaA2 single mutants. In contrast, a combined loss of cmaA1 and mmaA2 had no effect on mycolic acid modification compared to results with a loss of mmaA2 alone. Deletion of mmaA1 from M. tuberculosis abolishes trans cyclopropanation without accumulation of trans-unsaturated oxygenated mycolates, placing MmaA1 in the biosynthetic pathway for trans-cyclopropanated oxygenated mycolates before CmaA2. These results define new functions for the mycolic acid methyltransferases of M. tuberculosis and indicate a substantial redundancy of function for MmaA2 and CmaA2, the latter of which can function as both a cis and trans cyclopropane synthase for the oxygenated mycolates. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Keywords: unclassified drug; gene mutation; nonhuman; oxygen; bacterial strain; methyltransferase; mycolic acid; mycobacterium tuberculosis; bacterial proteins; methyltransferases; mycolic acids; oxygenation; gene expression regulation, bacterial; chemical modification; gene expression regulation, enzymologic; cmaa1 enzyme; cmaa2 enzyme; methoxymycolic acid; mmaa1 enzyme; mmaa2 enzyme; oxomycolic acid; cyclopropanation
Journal Title: Journal of Bacteriology
Volume: 192
Issue: 14
ISSN: 0021-9193
Publisher: American Society for Microbiology  
Date Published: 2010-07-01
Start Page: 3661
End Page: 3668
Language: English
DOI: 10.1128/jb.00312-10
PUBMED: 20472794
PROVIDER: scopus
PMCID: PMC2897352
DOI/URL:
Notes: --- - "Export Date: 20 April 2011" - "CODEN: JOBAA" - "Source: Scopus"
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MSK Authors
  1. Vivek K Rao
    3 Rao
  2. Michael Glickman
    109 Glickman
  3. Daniel Barkan
    9 Barkan