Journal Article

Ribosomal A-site interactions with near-cognate tRNAs drive stop codon readthrough

Lukeš, Julius, Roithová, Adriana, Paris, Zdeněk, Valášek, Leoš Shivaya, Miletínová, Petra, Beznosková, Petra, Záhonová, Kristína, Kachale, Ambar, Becker, Thomas, Čapková Pavlíková, Zuzana, Pospíšilová, Klára, Durante, Ignacio M.

2025

Overview

Transfer RNAs (tRNAs) serve as a dictionary for the ribosome translating the genetic message from mRNA into a polypeptide chain. In addition to this canonical role, tRNAs are involved in other processes such as programmed stop codon readthrough (SC-RT). There, tRNAs with near-cognate anticodons to stop codons must outcompete release factors and incorporate into the ribosomal decoding center to prevent termination and allow translation to continue. However, not all near-cognate tRNAs promote efficient SC-RT. Here, with the help of Saccharomyces cerevisiae and Tr ypanosoma brucei , we demonstrate that those tRNAs that promote efficient SC-RT establish critical contacts between their anticodon stem (AS) and ribosomal proteins Rps30/eS30 and Rps25/eS25 forming the decoding site. Unexpectedly, the length and well-defined nature of the AS determine the strength of these contacts, which is reflected in organisms with reassigned stop codons. These findings open an unexplored direction in tRNA biology that should facilitate the design of artificial tRNAs with specifically altered decoding abilities. Transfer RNAs (tRNAs) serve as a dictionary for ribosomes translating the genetic message from mRNA into protein. Here, the authors show that understanding specific interactions of tRNAs in the ribosomal decoding center may facilitate the treatment of genetic disorders.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 631/337/574/1789 / 631/337/574/1793 / 631/45/500 / 631/45/612/1230 / Anticodon - metabolism / Anticodons / Biochemistry / Biological Microscopy / Biomedical and Life Sciences / Codon, Terminator - genetics / Codon, Terminator - metabolism / Codons / Dictionaries / Genetic disorders / Life Sciences / Membrane Biology / Messages / mRNA / Nucleic Acid Conformation / Polypeptides / Protein Biosynthesis / Protein Structure / Proteins / Ribosomal proteins / Ribosomal Proteins - metabolism / Ribosomes / Ribosomes - metabolism / RNA, Transfer - chemistry / RNA, Transfer - genetics / RNA, Transfer - metabolism / Saccharomyces cerevisiae - genetics / Saccharomyces cerevisiae - metabolism / Stop codon / Termination factors / Transfer RNA / Translation termination / tRNA / Trypanosoma brucei brucei - genetics / Trypanosoma brucei brucei - metabolism