Two domains within σ~N (σ~54) cooperate for DNA binding

摘要

The σ-N (σ~N) subunit of the bacterial RNA polymerase is a sequence specific DNA-binding protein. The RNA polymerase holoenzyme formed with σ~N binds to promot- ers in an inactive form and only initiates transcription when activated by enhancer-binding positive control proteins. We now provide evidence to show that the DNA-binding activity of σ~N involves two distinct domains: a C-terminal DNA-binding do- main that directly contacts DNA and an adjacent domain that enhances DNA-binding activity.