PMID:17369838
| Citation |
Konevega, AL, Fischer, N, Semenkov, YP, Stark, H, Wintermeyer, W and Rodnina, MV (2007) Spontaneous reverse movement of mRNA-bound tRNA through the ribosome. Nat. Struct. Mol. Biol. 14:318-24 |
|---|---|
| Abstract |
During the translocation step of protein synthesis, a complex of two transfer RNAs bound to messenger RNA (tRNA-mRNA) moves through the ribosome. The reaction is promoted by an elongation factor, called EF-G in bacteria, which, powered by GTP hydrolysis, induces an open, unlocked conformation of the ribosome that allows for spontaneous tRNA-mRNA movement. Here we show that, in the absence of EF-G, there is spontaneous backward movement, or retrotranslocation, of two tRNAs bound to mRNA. Retrotranslocation is driven by the gain in affinity when a cognate E-site tRNA moves into the P site, which compensates the affinity loss accompanying the movement of peptidyl-tRNA from the P to the A site. These results lend support to the diffusion model of tRNA movement during translocation. In the cell, tRNA movement is biased in the forward direction by EF-G, which acts as a Brownian ratchet and prevents backward movement. |
| Links |
PubMed Online version:10.1038/nsmb1221 |
| Keywords |
Cryoelectron Microscopy; Escherichia coli/metabolism; Models, Molecular; Movement; Protein Biosynthesis; RNA, Bacterial/metabolism; RNA, Bacterial/ultrastructure; RNA, Messenger/metabolism; RNA, Messenger/ultrastructure; RNA, Transfer/metabolism; RNA, Transfer/ultrastructure; RNA, Transfer, Amino Acyl/metabolism; Ribosomes/metabolism; Ribosomes/ultrastructure |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.