Nucleotide sequence of RNA 3 of peanut stunt cucumovirus.

The nucleotide sequence of the RNA 3 of the peanut stunt virus strain J (PSV-J) was determined and compared with those of the cucumber mosaic virus strain Y (CMV-Y, subgroup I) and the tomato aspermy virus strain C (TAV-C) at both the nucleotide and protein levels. The RNA 3 of PSV-J consists of 2186 nucleotides and has two large open reading frames (ORFs). By analogy to other tripartite plant viruses, it is presumed that the first ORF (867 nucleotides) codes for the 3a protein and the second ORF (654 nucleotides) is the cistron of the coat protein which is expressed from subgenomic RNA 4 of 1010 nt residues. At the nucleotide level, PSV-J RNA 3 shows 60.6% homology to RNA 3 of CMV-Y and 66.3% to that of TAV-C, much lower than the value between the two CMV subgroups. For the 3a proteins there is 65.4% homology between PSV-J and CMV-Y and 70.2% homology between PSV-J and TAV-C. Although it has been known that PSV shows a distant serological relationship to CMV, the coat protein of PSV-J shows only 50% homology with that of CMV-Y.