The binding of aminoacyl sRNA and GTP to transferase I

Abstract

This chapter describes the discovery, resolution, purification, and function of elongation factors in microbiology. The availability of completely resolved and extensively purified components for peptide chain elongation and the development of strategies for assaying various intermediates, has allowed the examination of the role of elongation factors in the aminoacyl transfer reaction and of the interactions between factors and other essential reactants. If endogenous nascent peptidyl-tRNA was removed from ribosomes by treatment with puromycin, prior to the addition of ribosomes to the incubations containing the ternary complex, the aminoacyl-tRNA as such was detected on the ribosome—that is, none of the amino acids was recovered in peptide-bonded form. Two of the reactions in aminoacyl transfer thus appeared to be defined; the binding of aminoacyl-tRNA was dependent on EF-1 and guanosine triphosphate (GTP) and peptidyltransferase on ribosomes did not require an elongation factor or a nucleotide. Purified components are highly important in studies on biochemical reaction mechanisms.