The bacterial multidrug resistance regulator BmrR distorts promoter DNA to activate transcription

Abstract

BmrR is a member of the bacterial MerR transcription factor family that regulates the expression of the bacterial efflux pump Bmr. Here, the authors present the cryo-EM structure of a B. subtilis transcription activation complex (TAC) containing the RNA Polymerase (RNAP) core enzyme, σA, promoter DNA and ligand-bound BmrR, which reveals that in contrast to most other transcription factors BmrR does not directly interact with RNAP and instead activates transcription by modulating the shape of the core promoter.