Reorganisation of an RNA polymerase-promoter DNA complex for DNA melting.

ABSTRACT: Sigma factors, the key regulatory components of the bacterial RNA polymerase (RNAP), direct promoter DNA binding and DNA melting. The sigma(54)-RNAP forms promoter complexes in which DNA melting is only triggered by an activator and ATP hydrolysis-driven reorganisation of an initial sigma(54)-RNAP-promoter complex. We report that an initial bacterial RNAP-DNA complex can be reorganised by an activator to form an intermediate transcription initiation complex where full DNA melting has not yet occurred. Using sigma(54) as a chemical nuclease we now show that the reorganisation of the initial sigma(54)-RNAP-promoter complex occurs upon interaction with the activator at the transition point of ATP hydrolysis. We demonstrate that this reorganisation event is an early step in the transcription i

SUBMITTER: Burrows PC 

PROVIDER: S-EPMC524386 | biostudies-literature | 2004 Oct

REPOSITORIES: biostudies-literature