Large-Scale Movements of IF3 and tRNA during Bacterial Translation Initiation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27662086.
- Also identified by DOI 10.1016/j.cell.2016.08.074 and PMC identifier 5037330.
- 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
In bacterial translational initiation, three initiation factors (IFs 1-3) enable the selection of initiator tRNA and the start codon in the P site of the 30S ribosomal subunit. Here, we report 11 single-particle cryo-electron microscopy (cryoEM) reconstructions of the complex of bacterial 30S subunit with initiator tRNA, mRNA, and IFs 1-3, representing different steps along the initiation pathway. IF1 provides key anchoring points for IF2 and IF3, thereby enhancing their activities. IF2 positions a domain in an extended conformation appropriate for capturing the formylmethionyl moiety charged on tRNA. IF3 and tRNA undergo large conformational changes to facilitate the accommodation of the formylmethionyl-tRNA (fMet-tRNA(fMet)) into the P site for start codon recognition.
Medical subject headings
- Codon, Initiator
- Peptide Chain Initiation, Translational
- Prokaryotic Initiation Factor-3
- RNA, Messenger
- RNA, Transfer, Met
- Ribosome Subunits, Small, Bacterial
- Thermus thermophilus