Structural transitions in the transcription elongation complexes of bacterial RNA polymerase during σ-dependent pausing.

ABSTRACT: A transcription initiation factor, the σ(70) subunit of Escherichia coli RNA polymerase (RNAP) induces transcription pausing through the binding to a promoter-like pause-inducing sequence in the DNA template during transcription elongation. Here, we investigated the mechanism of σ-dependent pausing using reconstituted transcription elongation complexes which allowed highly efficient and precisely controlled pause formation. We demonstrated that, following engagement of the σ subunit to the pause site, RNAP continues RNA synthesis leading to formation of stressed elongation complexes, in which the nascent RNA remains resistant to Gre-induced cleavage while the transcription bubble and RNAP footprint on the DNA template extend in downstream direction, likely accompanied by DNA scrunching. Th

SUBMITTER: Zhilina E 

PROVIDER: S-EPMC3326312 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature