title: bkaR is a TetR-type repressor that controls an operon associated with branched-chain keto-acid metabolism in Mycobacteria.
abstract: This study describes how bkaR, a highly conserved mycobacterial TetR-like transcriptional repressor, regulates a number of nearby genes that have associations with branched-chain keto-acid metabolism. bkaR (MSMEG_4718) was deleted from the nonpathogenic species Mycobacterium smegmatis, and changes in global gene expression were assessed using microarray analysis and reporter gene studies. bkaR was found to directly control the expression of 10 genes in M. smegmatis, and its ortholog in Mycobacterium tuberculosis (Rv2506) is predicted to control at least 12 genes. A conserved operator motif was identified, and binding of purified recombinant M. tuberculosis BkaR to the motif was demonstrated. Analysis of the stoichiometry of binding showed that BkaR binds to the motif as a dimer.
authors.affiliation: Department of Pathology and Pathogen Biology, The Royal Veterinary College, Camden, London, UK.
authors.forename: Ricardo J C
authors.initials: RJ
authors.lastname: Balhana
authors.forename: Sade N
authors.initials: SN
authors.lastname: Swanston
authors.forename: Stephen
authors.initials: S
authors.lastname: Coade
authors.forename: Mike
authors.initials: M
authors.lastname: Withers
authors.forename: Mahmudul Hasan
authors.initials: MH
authors.lastname: Sikder
authors.forename: Neil G
authors.initials: NG
authors.lastname: Stoker
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Kendall
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007651:Keto Acids / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009876:Operon; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007651:Keto Acids; D012097:Repressor Proteins
keywords: MSMEG_4718; Rv2506; accA1; accD1; microarray; transcriptional regulation