Nucleotide sequence and structural analysis of two satellite RNAs associated with chicory yellow mottle virus.

The two satellite RNAs associated with CYMV infections were sequenced. The larger (sCYMV-L1) has only linear molecules 1145 nucleotides long, a poly(A) tail, a long open reading frame (ORF) coding for a protein of Mr 39,636 resembling in composition those of other large nepovirus satellite RNAs, a 5' leader sequence of 16 nucleotides and a 3' non-coding region of 40 nucleotides. In vitro translation of sCYMV-L1 yielded a protein product with a size that corresponded to that predicted from the sequence. The smaller satellite (sCYMV-S1) is 457 nucleotides long, has no ORF of significant length and no in vitro messenger activity. Both linear and circular forms of this satellite RNA were detected in infected tissues. Comparison of the sCYMV-S1 primary structure with the sequences of other small nepoviral satellites reveals large regions of homology. Analysis of the secondary structures derived from the sequences of the plus and minus strands suggests possible consensus sequences for their self-cleavage.