title: Structural basis for translation termination on the 70S ribosome.
abstract: At termination of protein synthesis, type I release factors promote hydrolysis of the peptidyl-transfer RNA linkage in response to recognition of a stop codon. Here we describe the crystal structure of the Thermus thermophilus 70S ribosome in complex with the release factor RF1, tRNA and a messenger RNA containing a UAA stop codon, at 3.2 A resolution. The stop codon is recognized in a pocket formed by conserved elements of RF1, including its PxT recognition motif, and 16S ribosomal RNA. The codon and the 30S subunit A site undergo an induced fit that results in stabilization of a conformation of RF1 that promotes its interaction with the peptidyl transferase centre. Unexpectedly, the main-chain amide group of Gln 230 in the universally conserved GGQ motif of the factor is positioned to contribute directly to peptidyl-tRNA hydrolysis.
authors.affiliation: Department of Molecular, Cell and Developmental Biology and Center for Molecular Biology of RNA, University of California at Santa Cruz, Santa Cruz, California 95064, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Laurberg
authors.forename: Haruichi
authors.initials: H
authors.lastname: Asahara
authors.forename: Andrei
authors.initials: A
authors.lastname: Korostelev
authors.forename: Jianyu
authors.initials: J
authors.lastname: Zhu
authors.forename: Sergei
authors.initials: S
authors.lastname: Trakhanov
authors.forename: Harry F
authors.initials: HF
authors.lastname: Noller
mesh_terms: D018388:Codon, Terminator / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D010443:Peptide Chain Termination, Translational; D010454:Peptide Termination Factors / Q000737:chemistry / Q000378:metabolism; D010458:Peptidyl Transferases / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012329:RNA, Bacterial / Q000378:metabolism; D012338:RNA, Ribosomal, 23S / Q000737:chemistry; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism*; D016963:Thermus thermophilus / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018388:Codon, Terminator; D010454:Peptide Termination Factors; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D012343:RNA, Transfer; D010458:Peptidyl Transferases