Formation and Function of the Active Ribosome Complex

Abstract

The enzymatic transfer of amino acids from aminoacyl RNA to polypeptides has been investigated by several laboratories (Arlinghaus et al., 1964; Allende et al., 1964; Hardesty et al., 1963; Nakamato et al., 1963; Schweet et al., 1965; Gasior and Moldave, 1965). At least two enzyme fractions are necessary for complete amino acid transfer. In the reticulocyte system (Arlinghaus et al., 1963, 1964) one enzyme, TF-1, promotes the binding of phenylalanyl RNA to a washed ribosome-poly U complex, while the other enzyme, the peptide synthetase (TF-2), is necessary for the formation of a peptide bond. No such enzymatic binding reaction has been observed with any other transfer system. The binding of aminoacyl RNA to ribosome mRNA complexes from E. coli does not require any added enzyme fraction (Allende et al., 1964). Non-enzymatic binding has also been studied with reticulocyte ribosomes. Nonenzymatic binding in the reticulocyte system required a drastic increase in...