Two DNA sites for MelR in the same orientation are sufficient for optimal MelR-dependent
The Escherichia coli melR gene encodes the MelR transcription factor that controls melibiose utilization. Expression of melR is autoregulated by MelR, which represses the melR promoter by binding to a target that overlaps the transcript start. Here, we show that MelR-dependent repression of the melR promoter can be enhanced by the presence of a second single DNA site for MelR located up to 250 base pairs upstream. Parallels with AraC-dependent repression at the araC–araBAD regulatory region and the possibility of the MelR-dependent repression loop formation are discussed. The results show that MelR bound at two distal loci can cooperate together in transcriptional repression.
Citation : Elrobh, M. S., Webster, C. L., Samarasinghe, S., Durose, D. and Busby, S. J.W. (2013) Two DNA sites for MelR in the same orientation are sufficient for optimal MelR-dependent repression at the Escherichia coli melR promoter. FEMS Microbiology Letters, 338 (1), pp. 62–67
Research Group : Infectious Disease Research Group
Peer Reviewed : Yes