Heterogeneity in the nucleotide sequence near the amino acid-accepting terminal of transfer RNA

Abstract

A transfer RNA charged with a 14C (or 3H) labelled amino acid was digested with ribonuclease T1. The resulting oligonucleotides were separated with a DEAE-cellulose column and the distribution of radioactivities was analysed. The oligonucleotide bearing the radioactivity corresponded to the terminal oligonucleotide which was originally adjacent to the first guanylic acid from the terminal in the transfer RNA molecule. The terminal sequences in transfer RNA beyond the CCA-terminal were different for each amino acid, and in some cases, for instance yeast valyl RNA or leucyl RNA, at least two kinds of terminal sequence were observed. These sequences were also specific for each organism; for example, the structures near the CCA-terminal of valyl RNA of yeast and rat were different from each other, and those of the leucyl RNA of yeast, rat and Escherichia coli were distinguishable.