Bacteriophage T4 MotA activator and the β-flap tip of RNA polymerase target the same set of σ70 carboxyl-terminal residues.

ABSTRACT: Sigma factors, the specificity subunits of RNA polymerase, are involved in interactions with promoter DNA, the core subunits of RNA polymerase, and transcription factors. The bacteriophage T4-encoded activator, MotA, is one such factor, which engages the C terminus of the Escherichia coli housekeeping sigma factor, σ(70). MotA functions in concert with a phage-encoded co-activator, AsiA, as a molecular switch. This process, termed sigma appropriation, inhibits host transcription while activating transcription from a class of phage promoters. Previous work has demonstrated that MotA contacts the C terminus of σ(70), H5, a region that is normally bound within RNA polymerase by its interaction with the β-flap tip. To identify the specific σ(70) residues responsible for interacting with MotA a

SUBMITTER: Bonocora RP 

PROVIDER: S-EPMC3234753 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature