An 8 nt RNA triggers a rate-limiting shift of RNA polymerase II complexes into elongation.

ABSTRACT: To better understand the critical conversions that RNA polymerase II complexes undergo during promoter escape, we determined in vitro the precise positions of the rate-limiting step and the last step requiring negative superhelicity or TFIIE and TFIIH. We found that both steps occur after synthesis of an 8 nt RNA during the stage encompassing translocation of the polymerase active site to the ninth register. When added to reactions just before this step, TFIIE and TFIIH overcame the requirement for negative superhelicity. The positions at which both steps occur were strictly dependent on RNA length as opposed to the location of the polymerase relative to promoter elements, showing that the transcript itself controls transformations during promoter escape. We propose a model in which comple

SUBMITTER: Hieb AR 

PROVIDER: S-EPMC1500975 | biostudies-literature | 2006 Jul

REPOSITORIES: biostudies-literature