Nucleotide sequence of starfish initiator tRNA.

The nucleotide sequence of starfish ovary initiator tRNA was determined to be pA-G-C-A-G-A-G-U-m1G-m2G-C-G-C-A-G-U-G-G-A-A-G-C-G-U-G-C-U-G-G-G-C-C-C-A-U-t6A-A-C-C-C-A-G-A-G-m7G-D-m5C-C-G-A-G-G-A-psi-C-G-m1A-A-A-C-C-U-C-G-C-U-C-U-G-C-U-A-C-C-AOH. The sequence was determined by a combination of the two different post-labeling techniques. Two-dimensional cellulose thin-layer chromatography was adopted for analysis of 5'-terminal nucleotides of tRNA fragments produced by formamide treatment. The nucleotide sequence of starfish initiator tRNA is very similar to that of mammalian cytoplasmic initiator tRNAs, but has seven different nucleotide residues and two modifications: residue 55 is psi instead of U, and residue 26 is unmodified G instead of m2G.