title: A posttermination ribosomal complex is the guanine nucleotide exchange factor for peptide release factor RF3.
abstract: The mechanism by which peptide release factor RF3 recycles RF1 and RF2 has been clarified and incorporated in a complete scheme for translation termination. Free RF3 is in vivo stably bound to GDP, and ribosomes in complex with RF1 or RF2 act as guanine nucleotide exchange factors (GEF). Hydrolysis of peptidyl-tRNA by RF1 or RF2 allows GTP binding to RF3 on the ribosome. This induces an RF3 conformation with high affinity for ribosomes and leads to rapid dissociation of RF1 or RF2. Dissociation of RF3 from the ribosome requires GTP hydrolysis. Our data suggest that RF3 and its eukaryotic counterpart, eRF3, have mechanistic principles in common.
authors.affiliation: Department of Cell and Molecular Biology, BMC, Uppsala University, Box 596, S-75124 Uppsala, Sweden. andrey.zavialov@icm.uu.se
authors.forename: A V
authors.initials: AV
authors.lastname: Zavialov
authors.forename: R H
authors.initials: RH
authors.lastname: Buckingham
authors.forename: M
authors.initials: M
authors.lastname: Ehrenberg
mesh_terms: D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D008954:Models, Biological; D010454:Peptide Termination Factors / Q000378:metabolism*; D011485:Protein Binding; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D010454:Peptide Termination Factors; C087971:peptide-chain-release factor 3; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate