RNA polymerase interactions with the upstream region of the E. coli tyrT promoter

Andrew A. Travers, Angus I. Lamond, Hilary A.F. Mace, Michael L. Berman

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

The rate of in vivo transcription from the E. coli tRNA and rRNA promoters depends on both cellular growth rate and aminoacid availability. To investigate the molecular mechanisms involved we determined the extent of interaction of RNA polymerase with the promoter of the tyrT stable RNA gene. We show that the enzyme can protect from DNAase I digestion a region of at least 85 bp of the wild-type tyrT promoter and only ∼62 bp of the lacUV5 mRNA promoter, the protected region extending on the antisense strand to ∼65 and 42 bp respectively upstream of the transcription startpoint. A mutant tyrT promoter, tyrTp27, is protected more extensively, RNA polymerase interactions extending to at least ∼-130. We propose that these upstream interactions of RNA polymerase perform two functions; activating initiation by polymerase bound at the primary binding site and increasing the concentration of polymerase in the vicinity of the tyrT promoter, thus allowing a high rate of maximal expression and enabling the promoter to be regulated over a wide range of activity.

Original languageEnglish
Pages (from-to)265-273
Number of pages9
JournalCell
Volume35
Issue number1
DOIs
Publication statusPublished - Nov 1983

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