The 2'-OH group of the peptidyl-tRNA stabilizes an active conformation of the ribosomal PTC.

ABSTRACT: The ribosome accelerates the rate of peptidyl transfer by >10(6)-fold relative to the background rate. A widely accepted model for this rate enhancement invokes entropic effects whereby the ribosome and the 2'-OH of the peptidyl-tRNA substrate precisely position the reactive moieties through an extensive network of hydrogen bonds that allows proton movement through them. Some studies, however, have called this model into question because they find the 2'-OH of the peptidyl-tRNA to be dispensable for catalysis. Here, we use an in vitro reconstituted translation system to resolve these discrepancies. We find that catalysis is at least 100-fold slower with the dA76-substituted peptidyl-tRNA substrate and that the peptidyl transferase centre undergoes a slow inactivation when the peptidyl-tRNA

SUBMITTER: Zaher HS 

PROVIDER: S-EPMC3116277 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature