Figure 5.
pAD1 region that regulates conjugation. The negative regulator TraA binds to the promoter P0 and dissociates when bound to the pheromone cAD1. A limited amount of transcription occurs from P0 to the terminator t1 in the uninduced state, allowing expression of the inhibitor iAD1. Pa is the promoter for mD, an RNA that enhances transcription termination at t1. Pa is also the promoter for traA. Induction results in transcription through t1 and t2 and into traE1, which encodes a positive regulator for conjugation-related determinants as well as itself.