ScoC regulates peptide transport and sporulation initiation in Bacillus subtilis

Oligopeptides are transported into Bacillus subtilis by two ABC transport s ystems, App and Opp. Transcription of the operon encoding the Opp system wa s found to occur during exponential growth, whereas the app operon was indu ced at the onset of stationary phase. Transcription of both operons was com pletely curtailed by overproduction of the ScoC regulator from a multicopy plasmid and was enhanced in strains with the scoC locus deleted. ScoC, a me mber of the MarR family of transcription regulators, is known from previous studies to be a negative regulator of sporulation and of protease producti on that acts by binding directly to the promoters of the genes it regulates . Since peptide transport is essential for inactivation of the negative reg ulation of sporulation by Rap phosphatases, the control of ScoC transcripti on repression activity plays a crucial role in the initiation of sporulatio n.