COMPLETION OF THE IMPATIENS NECROTIC SPOT VIRUS GENOME SEQUENCE AND GENETIC COMPARISON OF THE L-PROTEINS WITHIN THE FAMILY BUNYAVIRIDAE

The nucleotide sequence of the large (L) genome segment of impatiens n ecrotic spot virus (INSV) has been determined, and herewith the comple te nucleotide sequence of the whole, tripartite genome of this importa nt tospovirus has been elucidated. The L RNA is 8776 nucleotides long and of negative polarity, containing one large ORF on the viral comple mentary strand. Comparison of the deduced amino acid sequence of the I NSV L RNA primary translation product (330 . 3 kDa) with those of the L RNAs of other members of the family Bunyaviridae reveals that this p rotein represents the putative viral RNA-dependent RNA polymerase. A c luster dendrogram of the (putative) RNA polymerases indicates th at th e genera Tospovirus and Tenuivirus, though both encompassing ambisense plant-infecting viruses, have different affinities to the animal-infe cting Bunyaviridae, tospoviruses being most closely related to the gen us Bunyavirus, and tenuiviruses to the genus Phleboviros.