Ribosomal expansion segment contributes to translation fidelity via N-terminal processing of ribosomal proteins.

ABSTRACT: Eukaryotic ribosomes exhibit higher mRNA translation fidelity than prokaryotic ribosomes, partly due to eukaryote-specific ribosomal RNA (rRNA) insertions. Among these, expansion segment 27L (ES27L) on the 60S subunit enhances fidelity by anchoring methionine aminopeptidase (MetAP) at the nascent protein exit tunnel, accelerating co-translational N-terminal initiator methionine (iMet) processing. However, the mechanisms by which iMet processing influences translation fidelity remain unknown. Using yeast in vitro translation (IVT) systems, we found that inhibiting co-translational iMet processing does not impact ribosome decoding of ongoing peptide synthesis. Instead, our novel method to monitor iMet processing in vivo revealed that ribosomes purified from strains lacking MetAP ribosomal as

SUBMITTER: Nagai R 

PROVIDER: S-EPMC12117404 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature