COMPLETE NUCLEOTIDE-SEQUENCE AND ORGANIZATION OF THE RNA GENOME OF GROUNDNUT ROSETTE UMBRAVIRUS

Complementary DNA clones representing the entire genome of groundnut r osette umbravirus (GRV) were obtained and sequenced. GRV RNA comprises 4019 nucleotides and contains four large open reading frames (ORFs). The second ORF from the 5' end includes sequences that encode motifs c haracteristic of viral RNA-dependent RNA polymerases and is probably e xpressed by a -1 frameshift mechanism as a fusion protein with the pro duct of the 5'-most ORF. The other two ORFs are almost completely over lapping in different reading frames, and are probably expressed from s ubgenomic RNA. One of the putative products has significant sequence s imilarity with viral movement proteins. None of the putative proteins encoded by GRV RNA seems to be a structural protein. In genome organiz ation and in the amino acid sequences of its potential products, the R NA of GRV is similar to that of carrot mottle mimic umbravirus, and to the umbravirus-like RNA-2 of pea enation mosaic virus.