Nucleotide sequences and taxonomy of satsuma dwarf virus

The nucleotide sequences of genomic RNA1 (6795 nt) and RNA2 (5345 nt) of sa tsuma dwarf virus (SDV), a tentative member of the genus Nepovirus, were de termined. The deduced genome organization of SDV showed similarities to the organization in como-, faba- and nepoviruses, There is extensive amino aci d sequence similarity in the N-terminal regions of the proteins encoded by RNA1 and RNA2, as reported previously only for tomato ringspot nepovirus, H owever, unlike definitive nepoviruses, which have a single coat protein, SD V has two coat proteins. SDV RNA2 does not contain the long (> 1300 nt) 3' non-coding region characteristic of some nepoviruses, Phylogenetic analysis of SDV RNA polymerase placed SDV apart from como-, faba- and nepoviruses, These unique features suggest that SDV is distinct from the Comovirus, Faba virus and Nepovirus genera, and needs to be separated into a new genus, pro bably within the family Comoviridae.