Nitric oxide-responsive interdomain regulation targets the σ54-interaction surface in the enhancer binding protein NorR.

ABSTRACT: Bacterial enhancer binding proteins (bEBPs) are specialized transcriptional activators that assemble as hexameric rings in their active forms and utilize ATP hydrolysis to remodel the conformation of RNA polymerase containing the alternative sigma factor σ(54). Transcriptional activation by the NorR bEBP is controlled by a regulatory GAF domain that represses the ATPase activity of the central AAA+ domain in the absence of nitric oxide. Here, we investigate the mechanism of interdomain repression in NorR by characterizing substitutions in the AAA+ domain that bypass repression by the regulatory domain. Most of these substitutions are located in the vicinity of the surface-exposed loops that engage σ(54) during the ATP hydrolysis cycle or in the highly conserved GAFTGA motif that directly c

SUBMITTER: Bush M 

PROVIDER: S-EPMC2941729 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature