The effect of exogenous nutrients on the biosynthesis of Y base in tRNAPHe from Ehrlich ascites carcinoma.

In contrast to normal eukaryotic tissue, which contains a single isoaccepting species of tRNAPhe, the Ehrlich ascites carcinoma contains a spectrum of tRNAPhe species varying in their relative degree of posttranscriptional modification. The occurrence of multiple species involves an incomplete biosynthesis of the Y base, a complex hypermodified nucleoside located adjacent to the 3' end of the anticodon. Following intraperitoneal innoculation of a mixture of essential amino acids and vitamins into these mice, the majority of the tumor tRNAPhe behaved like the single liver tRNAPhe species. This suggests that under these conditions the modification of Y base was completed.