Isolation and properties of the main isoleucine trnas from lupinus luteus seeds

RPC-5 chromatography of [14C]isoleucyl-tRNA shows the presence of 5 tRNAIle species in lupin seeds. The two major species have been isolated using RPC-5 and Sepharose 4B chromatography. The acceptor activity of the purified tRNAs ranges from 1350 pmoles (tRNA2Ile) to 1510 pmoles (tRNA1Ile) of isoleucine per one A260 unit of tRNA. The two tRNAs have similar thermal denaturation profiles but differ in the composition of the major and minor bases, 3'-terminal nucleotide sequences, and the titration curves with MgCl2. It is concluded that the two major tRNAIle species are coded for by different genes.