5′- and 3′-Terminal Nucleotide Sequences of Tetrahymena pyriformis 17S rRNA

Ribonuclease T₁ oligonucleotides arising from the 5′ and 3′ termini of the 17S rRNA of Tetrahymena pyriformis were isolated by the diagonal method of Dahlberg (Dahlberg, J. E. (1968), Nature (London) 220, 548), and their nucleotide sequences were determined. The base sequence of the 3′-terminal fragment is (G)AUCAUUA_OH, which is identical to that found in other 17S–18S eucaryotic rRNA species. The nucleotide sequence of the 5′-terminal oligonucleotide is pAACCUGp, which is identical in length to that found in other eucaryotes and shows a partial but significant sequence homology to the 5′ RNase T1 oligonucleotides isolated from other eucaryotic species.