Structural basis for translation termination on the 70S ribosome.
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.
Laurberg
Martin
M
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.
Asahara
Haruichi
H
Korostelev
Andrei
A
Zhu
Jianyu
J
Trakhanov
Sergei
S
Noller
Harry F
HF
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
D018388:Codon, Terminator; D010454:Peptide Termination Factors; D012329:RNA, Bacterial; D012338:RNA, Ribosomal, 23S; D012343:RNA, Transfer; D010458:Peptidyl Transferases