Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 282, Issue 20, Pages 14729-14740Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M700271200
Keywords
-
Categories
Funding
- Medical Research Council [G0500590] Funding Source: Medline
- Wellcome Trust Funding Source: Medline
- Medical Research Council [G0500590] Funding Source: researchfish
- MRC [G0500590] Funding Source: UKRI
Ask authors/readers for more resources
Arabinofuranosyltransferase enzymes, such as EmbA, EmbB, and AftA, play pivotal roles in the biosynthesis of arabinogalactan, and the anti-tuberculosis agent ethambutol (EMB) targets arabinogalactan biosynthesis through inhibition of Mt-EmbA and Mt-EmbB. Herein, we describe the identification and characterization of a novel arabinofuranosyltransferase, now termed AftB (Rv3805c), which is essential in Mycobacterium tuberculosis. Deletion of its orthologue NCgl2780 in the closely related species Corynebacterium glutamicum resulted in a viable mutant. Analysis of the cell wall-associated lipids from the deletion mutant revealed a decreased abundance of cell wall-bound mycolic acids, consistent with a partial loss of mycolylation sites. Subsequent glycosyl linkage analysis of arabinogalactan also revealed the complete absence of terminal beta(1 -> 2)-linked arabinofuranosyl residues. The deletion mutant biochemical phenotype was fully complemented by either Mt-AftB or Cg-AftB, but not with muteins of Mt-AftB, where the two adjacent aspartic acid residues, which have been suggested to be involved in glycosyltransferase activity, were replaced by alanine. In addition, the use of C. glutamicum and C. glutamicum Delta aftB in an in vitro assay utilizing the sugar donor beta-D-arabinofuranosyl-1-monophosphoryl-decaprenol together with the neoglycolipid acceptor alpha-D-Araf-(1 -> 5)-alpha-D-Araf-O-C-8 as a substrate confirmed AftB as a terminal beta(1 -> 2) arabinofuranosyltransferase, which was also insensitive to EMB. Altogether, these studies have shed further light on the complexities of Corynebacterianeae cell wall biosynthesis, and Mt-AftB represents a potential new drug target.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available