Locking and unlocking of ribosomal motions.
Article Details
- CitationCopy to clipboard
Valle M, Zavialov A, Sengupta J, Rawat U, Ehrenberg M, Frank J
Locking and unlocking of ribosomal motions.
Cell. 2003 Jul 11;114(1):123-34.
- PubMed ID
- 12859903 [ View in PubMed]
- 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.