On the Nature of the Yeast Phenylalanine Transfer Ribonucleic Acid Synthetase Recognition Site

Purified yeast phenylalanyl transfer RNA synthetase can aminoacylate three Escherichia coli transfer RNAs. One of these tRNAs is E. coli valine transfer RNA which has been extensively purified and shown capable of being aminoacylated with phenylalanine and purified yeast phenylalanyl-tRNA synthetase. The extent of this heterologous aminoacylation is approximately 90%. A comparison of the structures of the three tRNAs (E. coli valine tRNA, yeast phenylalanine tRNA, and wheat phenylalanine tRNA) which are acceptable substrates for yeast phenylalanyl-tRNA synthetase shows that the dihydrouridine loop and stem of all three molecules are exceedingly similar. This region must therefore be involved in the recognition of a tRNA by this synthetase.