Function of sulfhydryl groups in ribosome-elongation factor G reactions. Assignment of guanine nucleotide binding site to elongation factor G.

Guanine-nucleotide exchange on ribosome-bound elongation factor G initiates the translocation of tRNAs

BACKGROUND During the translation of mRNA into polypeptide, elongation factor G (EF-G) catalyzes the translocation of peptidyl-tRNA from the A site to the P site of the ribosome. According to the 'classical' model, EF-G in the GTP-bound form promotes translocation, while hydrolysis of the bound GTP promotes dissociation of the factor from the post-translocation ribosome. According to a more rec...

Thiostrepton inhibits stable 70S ribosome binding and ribosome-dependent GTPase activation of elongation factor G and elongation factor 4

Thiostrepton, a macrocyclic thiopeptide antibiotic, inhibits prokaryotic translation by interfering with the function of elongation factor G (EF-G). Here, we have used 70S ribosome binding and GTP hydrolysis assays to study the effects of thiostrepton on EF-G and a newly described translation factor, elongation factor 4 (EF4). In the presence of thiostrepton, ribosome-dependent GTP hydrolysis i...

Elongation factor G protects a nuclease-sensitive site of 23 S RNA within the ribosome.

Form follows function: structure of an elongation factor G-ribosome complex.

Not so long ago, the idea of deriving functional models from just looking at large subcellular structures in different functional states seemed unrealistic. In the meantime, the visualization of such structures by three-dimensional reconstructions from cryoelectron microscopic images has made enormous progress. Studies on ribosomes, from both prokaryotes and eukaryotes, have been particularly r...

Elongation factor G bound to the ribosome in an intermediate state of translocation.

A key step of translation by the ribosome is translocation, which involves the movement of messenger RNA (mRNA) and transfer RNA (tRNA) with respect to the ribosome. This allows a new round of protein chain elongation by placing the next mRNA codon in the A site of the 30S subunit. Translocation proceeds through an intermediate state in which the acceptor ends of the tRNAs have moved with respe...