23] Elongation factor T-dependent GTP hydrolysis: Dissociation from aminoacyl-tRNA binding

Abstract

The elongation factor EFT (Tu + Ts) is required in the mechanism of polypeptide chain elongation for the formation of a ternary complex, aminoacyl-tRNA·EF Tu·GTP, which subsequently binds to the ribosome. In the binding process the GTP molecule is hydrolyzed and a binary complex, EF Tu·GDP, is released. EF Ts displaces the GDP molecule from this complex regenerating the original EFT (Tu + Ts) that can initiate a new cycle. In the presence of methanol, it has been observed that the EF T-dependent GTP hydrolysis, strongly stimulated by the alcohol, is uncoupled from the aminoacyl-tRNA binding to the ribosomes, which is not affected. This ribosome- and EF T-dependent uncoupled GTPase has some interesting characteristics and properties that are described in this chapter.