Investigations of the modular structure of bacterial promoters.

Bacterial RNA polymerase holoenzyme carries different determinants that contact different promoter DNA sequence elements. These contacts are essential for the recognition of promoters prior to transcript initiation. Here, we have investigated how active promoters can be built from different combinations of elements. Our results show that the contribution of different contacts to promoter activity is critically dependent on the overall promoter context, and that certain combinations of contacts can hinder transcription initiation.