Locking and unlocking of ribosomal motions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 12859903.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
During the ribosomal translocation, the binding of elongation factor G (EF-G) to the pretranslocational ribosome leads to a ratchet-like rotation of the 30S subunit relative to the 50S subunit in the direction of the mRNA movement. By means of cryo-electron microscopy we observe that this rotation is accompanied by a 20 A movement of the L1 stalk of the 50S subunit, implying that this region is involved in the translocation of deacylated tRNAs from the P to the E site. These ribosomal motions can occur only when the P-site tRNA is deacylated. Prior to peptidyl-transfer to the A-site tRNA or peptide removal, the presence of the charged P-site tRNA locks the ribosome and prohibits both of these motions.
Medical subject headings
- Eukaryotic Cells
- Peptide Elongation Factor G
- Protein Biosynthesis
- RNA, Messenger
- RNA, Transfer
- Ribosomes