Primary structure of AUA-specific isoleucine transfer ribonucleic acid from Escherichia coli

Abstract

The nucleotide sequence of an E. coli isoleucine tRNA (tRNAIleminor) specific for the codon AUA was determined by postlabeling procedures using only 2.5 .mu.g (0.05 A260 unit) of the material. The sequence was pG-G-C-C-C-C-U-s4U-A-G-C-U-C-A-G-U-Gm-G-D-D-A-G-A-G-C-A-A-G-C-G-A-C-U-N+-A-U-t6A-A-.PSI.-C-G-C-U-U-G-m7G-acp3U-C-G-C-U-G-G-T-.PSI.-C-A-A-G-U-C-C-A-G-C-A-G-G-G-G-C-C-A-C-C-AOH. The nucleotide sequences in the regions of the D arm and T.psi.C arm of tRNAIleminor were quite similar to the corresponding regions of tRNAIlemajor. The sequences in the CCA stem and anticodon stem of tRNAIleminor were different from those of tRNAIlemajor. The overall homology between the 2 isoleucine tRNA was 68%. E. coli tRNALys, tRNAMet, tRNA ValIIA and tRNAArg also have relatively high sequence homology with tRNAIleminor.