ANRV354-MI62-19 ARI 31 May 2008 16:51 R E V I E W S I N A D V A N C E Peptide Release on the Ribosome: Mechanism and Implications for Translational Control Elaine M. Youngman, Megan E. McDonald, and Rachel Green Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; email: ragreen@jhmi.edu Annu. Rev. Microbiol. 2008. 62:353–73 The Annual Review of Microbiology is online at micro.annualreviews.org This article’s doi: 10.1146/annurev.micro.61.080706.093323 Copyright c  2008 by Annual Reviews. All rights reserved 0066-4227/08/1013-0353$20.00 Key Words protein synthesis, translation termination, release factors, induced fit Abstract Peptide release, the reaction that hydrolyzes a completed protein from the peptidyl-tRNA upon completion of translation, is catalyzed in the active site of the large subunit of the ribosome and requires a class I re- lease factor protein. The ribosome and release factor protein cooperate to accomplish two tasks: recognition of the stop codon and catalysis of peptidyl-tRNA hydrolysis. Although many fundamental questions re- main, substantial progress has been made in the past several years. This review summarizes those advances and presents current models for the mechanisms of stop codon specificity and catalysis of peptide release. Finally, we discuss how these views fit into a larger emerging theme in the translation field: the importance of induced fit and conformational changes for progression through the translation cycle. 353 Review in Advance first posted online on June 10, 2008. (Minor changes may still occur before final publication online and in print.) Annu. Rev. Microbiol. 2008.62. Downloaded from arjournals.annualreviews.org by University of California - San Diego on 07/03/08. For personal use only.