Nucleotide sequence (n=159) of the amino-acid-accepting 3'-OH extremity of turnip-yellow-mosaic-virus RNA and the last portion of its coat-protein cistron.

The experiments described in this paper and the following one establish the sequence of the 3'-OH terminal 159 nucleotides of turnip yellow mosaic virus RNA. Uniformly 32P-labeled turnip yellow mosaic virus RNA was partially digested with T1 ribonuclease and the fragments were fractionated by polyacrylamide gel electrophoresis. Fragments originating from the 3'-OH end of the RNA molecule were identified by testing for the 3'-terminal oligonucleotide, C-COH, after total U2 ribonuclease hydrolysis. Once identified, the 3'-OH terminal fragments were sequenced by the methods of Sanger et al. The first 51 nucleotides of the longest of the sequenced fragments (158 nucleotides) extends into the 3'-terminal part of the coat protein cistron. The coat protein cistron is followed by a stretch of 108 untranslated nucleotides whose function, though still unknown, is probably linked to the tRNA-like properties which have been attributed to the 3'-OH extremity of this viral RNA. Two possible secondary structures are proposed for the sequence and the implications of the findings with regard to the tRNA-like properties of the extremity are discussed.