Format

Send to

Choose Destination
Mol Cell. 2007 Mar 9;25(5):751-64.

Structural basis for interaction of the ribosome with the switch regions of GTP-bound elongation factors.

Author information

1
Institut für Medizinische Physik und Biophysik, Charite-Universitätsmedizin Berlin, Ziegelstrasse 5-9, 10117 Berlin, Germany.

Abstract

Elongation factor G (EF-G) catalyzes tRNA translocation on the ribosome. Here a cryo-EM reconstruction of the 70S*EF-G ribosomal complex at 7.3 A resolution and the crystal structure of EF-G-2*GTP, an EF-G homolog, at 2.2 A resolution are presented. EF-G-2*GTP is structurally distinct from previous EF-G structures, and in the context of the cryo-EM structure, the conformational changes are associated with ribosome binding and activation of the GTP binding pocket. The P loop and switch II approach A2660-A2662 in helix 95 of the 23S rRNA, indicating an important role for these conserved bases. Furthermore, the ordering of the functionally important switch I and II regions, which interact with the bound GTP, is dependent on interactions with the ribosome in the ratcheted conformation. Therefore, a network of interaction with the ribosome establishes the active GTP conformation of EF-G and thus facilitates GTP hydrolysis and tRNA translocation.

PMID:
17349960
DOI:
10.1016/j.molcel.2007.01.027
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center