EmbA is an essential arabinosyltransferase in Mycobacterium tuberculosis

• DOI: 10.1099/mic.0.2007/012153-0
• Publication Date: 2008-01-03T04:48:13Z
• Authors: Anita G. Amin; Renan Goude; Libin Shi; Jian Zhang; Delphi Chatterjee; Tanya Parish
• Keywords: Mycobacterium smegmatis

The Emb proteins (EmbA, EmbB, EmbC) are mycobacterial arabinosyltransferases involved in the biogenesis of cell wall. EmbA and EmbB predicted to work unison as a heterodimer. formation crucial terminal hexaarabinoside motif [Araβ(1→2)Araα(1→5)] [Araβ(1→2)Araα(1→3)]Araα(1→5)Araα1→(Ara6) wall polysaccharide arabinogalactan. Studies conducted Mycobacterium smegmatis revealed that mutants with disruptions embA or embB viable, although growth rate was affected. In contrast, we demonstrate here is an essential gene tuberculosis, since deletion chromosomal could only be achieved when second functional copy provided on integrated vector. Complementation mutant M. by tuberculosis confirmed it encodes arabinosyltransferase. We identified promoter for located immediately upstream gene, indicating expressed independently from embC. Promoter activity P (Mtb) sevenfold lower assayed compared latter not good host genetic analysis expression. remained constant throughout phases after stress treatment, reduced during hypoxia-induced non-replicating persistence. Ethambutol exposure had no effect activity. These data arabinosyltransferase which constitutively plays critical role tuberculosis.