Cryo-EM structure of Escherichia coli σ⁷⁰ RNA polymerase and promoter DNA complex revealed a role of σ non-conserved region during the open complex formation.

ABSTRACT: First step of gene expression is transcribing the genetic information stored in DNA to RNA by the transcription machinery including RNA polymerase (RNAP). In Escherichia coli, a primary σ⁷⁰ factor forms the RNAP holoenzyme to express housekeeping genes. The σ⁷⁰ contains a large insertion between the conserved regions 1.2 and 2.1, the σ non-conserved region (σ_NCR), but its function remains to be elucidated. In this study, we determined the cryo-EM structures of the E. coli RNAP σ⁷⁰ holoenzyme and its complex with promoter DNA (open complex, RPo) at 4.2 and 5.75 Å resolutions, respectively, to reveal native conformations of RNAP and DNA. The RPo structure presented here found an interaction between the σ_NCR and promoter DNA

SUBMITTER: Narayanan A 

PROVIDER: S-EPMC5949986 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature