Pseudoverification of Mixed Aminoacyl Transfer Ribonucleic Acids

A mixture of unresolved tRNAs from Escherichia coli B has been acylated with a mixture of 18 3H-amino acids, and the purified, correctly acylated aminoacyl-tRNAs were incubated with pure isoleucyl-tRNA synthetase under conditions in which it hydrolyzes some noncognate aminoacyl-tRNAs (see the preceding paper). A micromethod was used to resolve and identify the 3H-amino acids released. The results indicate that isoleucyl-tRNA synthetase can interact with and deacylate 15 of the 18 aminoacyl-tRNA species used. The occurrence of this reaction indicates an interaction between these tRNAs and isoleucyl-tRNA synthetase. In addition, the specificity of the verification, or hydrolysis, reaction is illuminated by the particular nature of the residues which are resistant to hydrolysis.