Structural insights into ribosomal rescue by Dom34 and Hbs1 at near-atomic resolution.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27995908.
- Also identified by DOI 10.1038/ncomms13521 and PMC identifier 5187420.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The surveillance of mRNA translation is imperative for homeostasis. Monitoring the integrity of the message is essential, as the translation of aberrant mRNAs leads to stalling of the translational machinery. During ribosomal rescue, arrested ribosomes are specifically recognized by the conserved eukaryotic proteins Dom34 and Hbs1, to initiate their recycling. Here we solve the structure of Dom34 and Hbs1 bound to a yeast ribosome programmed with a nonstop mRNA at 3.3 Å resolution using cryo-electron microscopy. The structure shows that Domain N of Dom34 is inserted into the upstream mRNA-binding groove via direct stacking interactions with conserved nucleotides of 18S rRNA. It senses the absence of mRNA at the A-site and part of the mRNA entry channel by direct competition. Thus, our analysis establishes the structural foundation for the recognition of aberrantly stalled 80S ribosomes by the Dom34·Hbs1·GTP complex during Dom34-mediated mRNA surveillance pathways.
Medical subject headings
- Cell Cycle Proteins
- Endoribonucleases
- GTP-Binding Proteins
- HSP70 Heat-Shock Proteins
- Peptide Elongation Factors
- Ribosomes
- Saccharomyces cerevisiae Proteins