4wq1
From Proteopedia
Complex of 70S ribosome with tRNA-Tyr and mRNA with C-A mismatch in the first position in the A-site.
Structural highlights
FunctionRS18_THET8 Located on the back of the platform of the 30S subunit where it stabilizes the close packing of several RNA helices of the 16S rRNA. Forms part of the Shine-Dalgarno cleft in the 70S ribosome, where it probably interacts with the Shine-Dalgarno helix.[HAMAP-Rule:MF_00270] Publication Abstract from PubMedThe decoding of mRNA on the ribosome is the least accurate process during genetic information transfer. Here we propose a unified decoding mechanism based on 11 high-resolution X-ray structures of the 70S ribosome that explains the occurrence of missense errors during translation. We determined ribosome structures in rare states where incorrect tRNAs were incorporated into the peptidyl-tRNA-binding site. These structures show that in the codon-anticodon duplex, a G.U mismatch adopts the Watson-Crick geometry, indicating a shift in the tautomeric equilibrium or ionization of the nucleobase. Additional structures with mismatches in the 70S decoding centre show that the binding of any tRNA induces identical rearrangements in the centre, which favours either isosteric or close to the Watson-Crick geometry codon-anticodon pairs. Overall, the results suggest that a mismatch escapes discrimination by preserving the shape of a Watson-Crick pair and indicate that geometric selection via tautomerism or ionization dominates the translational infidelity mechanism. Structural insights into the translational infidelity mechanism.,Rozov A, Demeshkina N, Westhof E, Yusupov M, Yusupova G Nat Commun. 2015 Jun 3;6:7251. doi: 10.1038/ncomms8251. PMID:26037619[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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