Abstract
Two fractions of phenylalanine tRNA (tRNA(Phe) (1) and tRNA(Phe) (2)) were purified by BD-cellulose and RPC-5 chromatography of crude tRNA isolated from barley embryos. Successive RPC-5 rechromatography runs of tRNA(Phe) (2) showed its conversion into more stable tRNA(Phe) (1), suggesting that the two fractions have essentially the same primary structure. Both tRNA(Phe) (1) and tRNA(Phe) (2) had about the same acceptor activity, but tRNA(Phe) (2) was aminoacylated much faster than tRNA(Phe) (1). RPC-5 chromatography of crude aminoacylated tRNA showed higher contents of phe-tRNA(Phe) (2) than of phe-tRNA(Phe) (1) but the ratio of these two fractions estimated by relative fluorescence intensity was about 1. Fluorescence spectra of tRNA(Phe) from barley embryos suggest that it contains Y base similar to Y(w) from wheat tRNA(Phe).