FIG. 7.

Model for the recognition of the hcn promoter P2 by the transcriptional regulators ANR, LasR, and RhlR and their interaction with RNA polymerase. αCTD (C-terminal domain of α) and αNTD (N-terminal domain of α) of RNA polymerase are shown as separate domains joined by a linker. Positions relative to the transcriptional start site T2 are indicated below the sequence. This model has been adapted from that proposed by Belyaeva et al. (4) for CRP-dependent promoter activation. During oxygen limitation, ANR blocks transcription from site T1 by binding to the corresponding −10 sequence (in brackets).