Catabolite repression of dra–nupC–pdp operon expression in Bacillus subtilis

摘要

Expression of the Bacillus subtilisdra–nupC–pdp operon is subject to catabolite repression by glucose. It was shown that a cis-acting catabolite-responsive element (CRE) sequence located 64?bp downstream of the transcription-start site mediated catabolite repression of the dra–nupC–pdp operon as it does for many other B. subtilis genes. Point mutations in the CRE sequence caused the loss of catabolite repression of the operon. Catabolite repression of dra–nupC–pdp expression was relieved in a ccpA mutant and was found to be dependent on both HPr and the HPr-like protein Crh. Furthermore, a transcription-repair coupling factor, Mfd, was also found to be involved in the glucose repression of dra–nupC–pdp expression. By the use of in vitro gel mobility shift analysis, a specific HPr-P dependent binding of CcpA to the dra CRE site was demonstrated.