Back to Search
Start Over
Visualization of elongation factor G on the Escherichia coli 70S ribosome: the mechanism of translocation.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1998 May 26; Vol. 95 (11), pp. 6134-8. - Publication Year :
- 1998
-
Abstract
- 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.
- Subjects :
- Crystallography, X-Ray
Escherichia coli metabolism
Escherichia coli ultrastructure
Peptide Elongation Factor G
Peptide Elongation Factors chemistry
Peptide Elongation Factors ultrastructure
Protein Conformation
Ribosomes chemistry
Ribosomes ultrastructure
Escherichia coli genetics
Peptide Elongation Factors genetics
Protein Biosynthesis
Ribosomes genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 95
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 9600930
- Full Text :
- https://doi.org/10.1073/pnas.95.11.6134