The nucleotide sequences of the initiator transfer RNAs from bean cytoplasm and chloroplasts

Abstract

The initiator tRNAs^Met from the cytoplasm and chloroplasts of Phaseolus vulgaris have been purified and sequenced. The sequence of bean oytoplasmic initiatortRNAs_i^Met is : pA-U-C-A-G-A-G-U-m¹G-m²G-C-G-C-A-G-C-G-G-A-A-G-C-G-U-m²G-G-V-G-G-G-C-C-C-A-V-t⁶A-A-C-C-C-A-C-A-G-m⁷G-D-m⁵C-C-C-A-G-G-A-ψ-C-G-m¹-A-A-C-C-U-Gm-G-C-U-C-U-G-A-U-A-C-C-A_OH. The sequence of bean cytoplasmic tRNA_i^Met is almost identical to that of wheat germ and shows a high degree of homology with other cytoplasmic initiator tRNAs. The sequence of bean chloroplast initiator tRSA_f^Met is : pC-G-C-G-G-A-G-U-A-G-A-G-C-A-A-C-U-U-Gm-G-D-A-G-C-V-C-G-C-A-A-G-G-C-U-C-A-U-A-A-C-C-U-U-G-A-A-m⁷G-acp³U-U-A-C-G-G-G-T-ψ-C-A-A-A-U-C-C-C-G-U-C-U-C-C-G-C-A-A-C-C-A_OH. Bean chloroplast initiator tRSA_f^Met sequence shows procaryotic characteristics at the 5′ end of the acceptor stem and in the TψC loop, but also contains some distinctive features.