FIG 4 .

ipuS promoter mapping by 5′ RACE. (A) The ipuS transcription start site was identified by 5′ RACE and is located within the full-length ipuA coding sequence. Inversion of element to the “ON” state orientates the promoter toward ipuR/upaE. The inverted repeats are indicated by the dotted lines. (B) A predicted promoter was identified in proximity to the mapped transcription start site that most closely matches a σ⁷⁰ consensus promoter. Locations of the predicted −35 and −10 regions, spacer lengths, and transcription start site are indicated. Bases matching consensus are shown in bold.