Enzymatische Spaltungen von Serin-t-RNA-Fraktionen

Enzymatic splitting of serine-specific transfer -RNA Serine-specific t-RNA I and II fractions, which had been largely separated from each other and from other t-RNA's by countercurrent distribution, were investigated. The splitting products obtained with pancreatic and T 1 -ribonucleases (EC 2.7.7.16 and EC 3.1.4.8 respectively) were separated by column chromatography (Figs. 1 and 2) and further purified. Some oligonucleotides were further degraded enzymically and the products separated by column chromatography (Tables I–III). One each of N 2 -dimethyl-Gp, 5-methyl-Cp, rTp, Ip, 2′- O -methyl-Gp, 2′- O -methyl-Up; three ψ-Up's and two nucleotides with the properties of 4,5-dihydro-Up were found in defined sequences of the serine t-RNA's. Degradation of a serine t-RNA fraction with snake venom phosphodiesterase (EC 3.1.4.1) proceeded quickly at first and then slowed down (Figs. 3 and 4). The 5′-mononucleotides split off in the fast initial phase were analyzed.