INTERACTION OF CODY, A NOVEL BACILLUS-SUBTILIS DNA-BINDING PROTEIN, WITH THE DPP PROMOTER REGION

The product of the codY gene is required for nutritional repression of the Bacillus subtilis dipeptide permease operon (dpp), an operon expr essed at early stationary phase in nutrient-rich medium. Though unrela ted to any known DNA-binding protein, CodY was shown to bind specifica lly to the dpp promoter region. DNase I footprinting experiments revea led that the CodY-protected region encompasses the dpp transcription s tart site and overlaps with the region protected by another regulatory protein, AbrB. CodY and AbrB were found to compete, in vitro, for bin ding to the dpp promoter region. Binding of CodY was altered in mutant s defective in nutritional regulation.