Sequence-independent upstream DNA-alphaCTD interactions strongly stimulate Escherichia coli RNA polymerase-lacUV5 promoter association.

ABSTRACT: The C-terminal domains of the two alpha-subunits (alphaCTD) in Escherichia coli RNA polymerase (RNAP) recognize specific sequences called UP elements in some promoters. These interactions can increase transcription dramatically. Previously, effects of upstream DNA-alphaCTD interactions on transcription were quantified relative to control promoters with nonspecific DNA sequences substituted for UP elements. However, contributions of nonspecific upstream DNA-alphaCTD interactions to promoter activity have not been evaluated extensively. Here, we examine effects of removal of alphaCTD, upstream promoter DNA, or both on the rate of open-complex formation with promoters that lack UP elements. Deletion of alphaCTD decreased the composite second-order association rate constant, k(a), of RNAP for

SUBMITTER: Ross W 

PROVIDER: S-EPMC544289 | biostudies-literature | 2005 Jan

REPOSITORIES: biostudies-literature