Visualization of elongation factor G on the Escherichia coli 70S ribosome: The mechanism of translocation
AUTOR(ES)
Agrawal, Rajendra K.
FONTE
The National Academy of Sciences
RESUMO
During protein synthesis, elongation factor G (EF-G) binds to the ribosome and promotes the step of translocation, a process in which tRNA moves from the A to the P site of the ribosome and the mRNA is advanced by one codon. By using three-dimensional cryo-electron microscopy, we have visualized EF-G in a ribosome–EF-G–GDP–fusidic acid complex. Fitting the crystal structure of EF-G–GDP into the cryo density map reveals a large conformational change mainly associated with domain IV, the domain that mimics the shape of the anticodon arm of the tRNA in the structurally homologous ternary complex of Phe-tRNAPhe, EF-Tu, and a GTP analog. The tip portion of this domain is found in a position that overlaps the anticodon arm of the A-site tRNA, whose position in the ribosome is known from a study of the pretranslocational complex, implying that EF-G displaces the A-site tRNA to the P site by physical interaction with the anticodon arm.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=27598Documentos Relacionados
- Visualization of ribosome-recycling factor on the Escherichia coli 70S ribosome: Functional implications
- Chemical crosslinking of elongation factor G to the 23S RNA in 70S ribosomes from Escherichia coli.
- DISSOCIATION OF 70S RIBOSOMES: SOME PROPERTIES OF THE DISSOCIATING FACTOR FROM Bacillus stearothermophilus AND Escherichia coli*
- Arginines 29 and 59 of elongation factor G are important for GTP hydrolysis or translocation on the ribosome
- Accumulation of 70S Monoribosomes in Escherichia coli After Energy Source Shift-Down