5ibb

Publication Abstract from PubMed

Precise conversion of genetic information into proteins is essential to cellular health. However, a margin of error exists and is at its highest on the stage of translation of mRNA by the ribosome. Here we present three crystal structures of 70S ribosome complexes with messenger RNA and transfer RNAs and show that when a G*U base pair is at the first position of the codon-anticodon helix a conventional wobble pair cannot form because of inescapable steric clash between the guanosine of the A codon and the key nucleotide of decoding center adenosine 1493 of 16S rRNA. In our structure the rigid ribosomal decoding center, which is identically shaped for cognate or near-cognate tRNAs, forces this pair to adopt a geometry close to that of a canonical G*C pair. We further strengthen our hypothesis that spatial mimicry due either to base tautomerism or ionization dominates the translation infidelity mechanism.

The ribosome prohibits the G*U wobble geometry at the first position of the codon-anticodon helix.,Rozov A, Westhof E, Yusupov M, Yusupova G Nucleic Acids Res. 2016 May 12. pii: gkw431. PMID:27174928^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.