X-ray crystal structure of Escherichia coli RNA polymerase ?70 holoenzyme.

ABSTRACT: Escherichia coli RNA polymerase (RNAP) is the most studied bacterial RNAP and has been used as the model RNAP for screening and evaluating potential RNAP-targeting antibiotics. However, the x-ray crystal structure of E. coli RNAP has been limited to individual domains. Here, I report the x-ray structure of the E. coli RNAP ?(70) holoenzyme, which shows ? region 1.1 (?1.1) and the ? subunit C-terminal domain for the first time in the context of an intact RNAP. ?1.1 is positioned at the RNAP DNA-binding channel and completely blocks DNA entry to the RNAP active site. The structure reveals that ?1.1 contains a basic patch on its surface, which may play an important role in DNA interaction to facilitate open promoter complex formation. The ? subunit C-terminal domain is positioned next to ? domain 4 with a fully stretched linker between the N- and C-terminal domains. E. coli RNAP crystals can be prepared from a convenient overexpression system, allowing further structural studies of bacterial RNAP mutants, including functionally deficient and antibiotic-resistant RNAPs.

SUBMITTER: Murakami KS 

PROVIDER: S-EPMC3610985 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature