Acceptor activity of tRNAPhe from yeasts under special conditions of aminoacylation.

The reaction of aminoacylation of tRNAPhe from yeasts and the erroneous acylation of total tRNA from E. coli by yeast phenylalanyl-tRNA synthetase under special conditions was studied. It was shown that the decrease in the degree of acylation of tRNAPhe and the increase in the degree of erroneous acylation of the total tRNA from E. coli are associated with the influence of these conditions on the structure of tRNA, and not on the structure or specificity of the enzyme. It was found that under special conditions of acylation, tRNAPhe exists in two conformations: acylatable and nonacylatable. The ability for complete acylation is restored after the transfer of tRNAPhe under classical conditions of acylation. The results are discussed from the standpoint of possible mechanisms of the recognition of tRNA by aminoacyl-tRNA synthetases.