Fractionation of Transfer Ribonucleic Acids from Torulopsis utilis

V. Purification of the Phenylalanine, Lysine and Histidine Transfer Ribonucleic Acids

Abstract

By a series of chromatography on a DEAE-Sephadex column with the ammonium sulfate, phosphate and borate systems, the two phenyl-alanine and one histidine tRNA's were highly purified. The phenyl-alanine and lysine tRNA's were respectively resolved into three com-ponents, while the histidine-acceptor activity did not display the hetero-geneity.
Distribution of oligonucleotide fragments produced on pancreatic RNase I [EC 2.7.7.16] digestion of the purified preparations was quite characteristic of the amino acid specific tRNA's and, on the other hand, quite similar among the multiple components specific for the same amino acid. Preliminary results on the sequence analyses of the phenyl-alanine tRNA I have revealed several important sequences. Especially the following fragments should be noted: 5'-terminal, pGpCp, 3'-termial, CpApCpCpA, common sequence, (Tp, Ψp, Cp)Gp, and large fragment, Ap2'OMeCpUp[(2'OMeGpAp, Ap, X)Ψp, Cp, ApUp]Gp, and so on. The difference between the phenylalanine tRNA's I and III had not yet been found in nucleotide sequence examined. On the other hand, certain different sequences, together with the similarity, were noted between Torula and Baker's yeast.