Strength and Regulation without Transcription Factors: Lessons from Bacterial rRNA Promoters
This extract was created in the absence of an abstract.
Excerpt
The determinants responsible for transcription from aparticular promoter at a specific time in growth or development are most typically protein factors that interact directly or indirectly with RNA polymerase (RNAP). However, during the last few years, our studies on ribosomalRNA transcription in Escherichia coli have led us to appreciate the role of the basal transcription apparatus (i.e.,the promoter, RNAP, and RNAP's nucleoside triphosphate substrates) as major determinants of transcriptionand its regulation. Although there are protein factors thatinfluence E. coli rRNA transcription by interacting directly with the basal transcription apparatus, major features of rRNA transcription, i.e., the extraordinarystrength of rRNA promoters and the regulation of transcription initiation with the growth rate, are determined(at least in the rrnB operon) primarily by features intrinsic to the promoter-RNAP interaction itself and by theconcentrations of the initiating nucleoside triphosphates(NTPs) in the cell. These features turn out to be relevantnot only to transcription of rRNA, but to transcription ofother promoters as well...
