Forks, pincers, and triggers: the tools for nucleotide incorporation and translocation in multi-subunit RNA polymerases.
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.
Erie
Dorothy A
DA
Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, United States. derie@unc.edu
Kennedy
Scott R
SR
D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D009711:Nucleotides / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D021122:Protein Subunits
D009711:Nucleotides; D021122:Protein Subunits; D012321:DNA-Directed RNA Polymerases