The actinobacterial transcription factor RbpA binds to the principal sigma subunit of RNA polymerase.

ABSTRACT: RbpA is a small non-DNA-binding transcription factor that associates with RNA polymerase holoenzyme and stimulates transcription in actinobacteria, including Streptomyces coelicolor and Mycobacterium tuberculosis. RbpA seems to show specificity for the vegetative form of RNA polymerase as opposed to alternative forms of the enzyme. Here, we explain the basis of this specificity by showing that RbpA binds directly to the principal σ subunit in these organisms, but not to more diverged alternative σ factors. Nuclear magnetic resonance spectroscopy revealed that, although differing in their requirement for structural zinc, the RbpA orthologues from S. coelicolor and M. tuberculosis share a common structural core domain, with extensive, apparently disordered, N- and C-terminal regions. The Rbp

SUBMITTER: Tabib-Salazar A 

PROVIDER: S-EPMC3675491 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature