Structures of modified eEF2 80S ribosome complexes reveal the role of GTP hydrolysis in translocation.

ABSTRACT: On the basis of kinetic data on ribosome protein synthesis, the mechanical energy for translocation of the mRNA-tRNA complex is thought to be provided by GTP hydrolysis of an elongation factor (eEF2 in eukaryotes, EF-G in bacteria). We have obtained cryo-EM reconstructions of eukaryotic ribosomes complexed with ADP-ribosylated eEF2 (ADPR-eEF2), before and after GTP hydrolysis, providing a structural basis for analyzing the GTPase-coupled mechanism of translocation. Using the ADP-ribosyl group as a distinct marker, we observe conformational changes of ADPR-eEF2 that are due strictly to GTP hydrolysis. These movements are likely representative of native eEF2 motions in a physiological context and are sufficient to uncouple the mRNA-tRNA complex from two universally conserved bases in the rib

SUBMITTER: Taylor DJ 

PROVIDER: S-EPMC1864975 | biostudies-literature | 2007 May

REPOSITORIES: biostudies-literature