Specific degradation of a plant leucyl transfer ribonucleic Acid by a factor in the homologous synthetase preparation.

Partially purified aminoacyl synthetase preparations from pea roots (Pisum sativum L. var. Alaska) contain a heat-labile factor which can degrade leucyl-tRNA(6) (leu) to a new species. The singular electrophoretic and chromatographic mobilities, the isoprenoid nucleoside content, and the charging characteristics of the new species (designated leucyl-tRNA(L) (leu)), suggest that it is a fragment of tRNA(6) (leu) containing at least that portion of the original molecule extending from the 3' terminus to the anticodon. Conversion appears to be highly specific since neither bulk tRNA, the other leucine tRNA subspecies, nor tyrosine, phenylalanine, or tryptophan tRNAs are susceptible to degradation during incubation with the synthetase preparation.