Control of transcriptional fidelity by active center tuning as derived from RNA polymerase endonuclease reaction.

ABSTRACT: Precise transcription by cellular RNA polymerase requires the efficient removal of noncognate nucleotide residues that are occasionally incorporated. Mis-incorporation causes the transcription elongation complex to backtrack, releasing a single strand 3'-RNA segment bearing a noncognate residue, which is hydrolyzed by the active center that carries two Mg(2+) ions. However, in most x-ray structures only one Mg(2+) is present. This Mg(2+) is tightly bound to the active center aspartates, creating an inactive stable state. The first residue of the single strand RNA segment in the backtracked transcription elongation complex strongly promotes transcript hydrolytic cleavage by establishing a network of interactions that force a shift of stably bound Mg(2+) to release some of its aspartate coor

SUBMITTER: Sosunova E 

PROVIDER: S-EPMC5396497 | biostudies-literature | 2013 Mar

REPOSITORIES: biostudies-literature