Complete nucleotide sequence and organization of the RNA genome of groundnut rosette umbravirus

Complementary DNA clones representing the entire genome of groundnut rosette 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 characteristic of viral RNA-dependent RNA polymerases and is probably expressed by a -1 frameshift mechanism as a fusion protein with the product of the 5'-most ORF. The other two ORFs are almost completely overlapping in different reading frames, and are probably expressed from subgenomic RNA. One of the putative products has significant sequence similarity with viral movement proteins. None of the putative proteins encoded by GRV RNA seems to be a structural protein. In genome organization and in the amino acid sequences of its potential products, the RNA of GRV is similar to that of carrot mottle mimic umbravirus, and to the umbravirus-like RNA-2 of pea enation mosaic virus.