Hypoxia-activated cytochrome bd expression in Mycobacterium smegmatis is cyclic AMP receptor protein dependent.

ABSTRACT: Mycobacteria are obligate aerobes and respire using two terminal respiratory oxidases, an aa3-type cytochrome c oxidase and a cytochrome bd-type menaquinol oxidase. Cytochrome bd is encoded by cydAB from the cydABDC gene cluster that is conserved throughout the mycobacterial genus. Here we report that cydAB and cydDC in Mycobacterium smegmatis constitute two separate operons under hypoxic growth conditions. The transcriptional start sites of both operons were mapped, and a series of cydA-lacZ and cydD-lacZ transcriptional reporter fusions were made to identify regulatory promoter elements. A 51-bp region was identified in the cydAB promoter that was required for maximal cydA-lacZ expression in response to hypoxia. A cyclic AMP receptor protein (CRP)-binding site (viz. GTGAN6CCACC) was iden

SUBMITTER: Aung HL 

PROVIDER: S-EPMC4135660 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature