Forks, pincers, and triggers: the tools for nucleotide incorporation and translocation in multi-subunit RNA polymerases.

ABSTRACT: The central role of RNA polymerase (RNAP) is to catalyze the processive synthesis of a growing RNA transcript. Recent structural and biophysical data have led to a deeper understanding of the nucleotide addition cycle and insight into the structure-function relationships that govern transcription elongation. In this review, we discuss kinetic data on nucleotide incorporation in the context of crystal structures, which show RNAP in multiple conformations. We present a facilitated Brownian ratchet model of nucleotide incorporation, in which templated NTP binding to a non-catalytic site in the main channel promotes the conformational changes that lead to opening of the catalytic site and translocation.

SUBMITTER: Erie DA 

PROVIDER: S-EPMC3979713 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature