The S
RNA segment of Dugbe (DUG) virus (Nairovirus; Bunyaviridae) was sequenced from three overlapping
cDNA clones and by primer extension. The S
RNA is 1712
nucleotides in length and contains one large open reading frame (ORF) of 1326
nucleotides coding for a 49.4-kDa
protein on viral complementary (vc)
RNA. This
protein in size corresponds to the DUG nucleocapsid (N)
protein (P. Cash, 1985, J. Gen. Virol. 66, 141-148). The 49.4-kDa product was expressed as a fusion
protein with
beta-galactosidase in Escherichia coli cells and confirmed as DUG N
protein by Western blotting with DUG N-specific
monoclonal antibody. An additional ORF of 150
nucleotides coding for a possible 5.9-kDa
protein is present in the +1 reading frame, 3' to the N
protein ORF on vcRNA. DUG S segment
mRNA was found to be essentially full length. No evidence was obtained for the existence of a smaller
mRNA species that could code for a 5.9-kDa
protein. Comparisons of the DUG S RNA sequence and predicted N
protein amino acid sequence, with the respective sequences of snowshoe hare, La Crosse (bunyaviruses), Punta Toro,
Sandfly fever Sicilian (phleboviruses), and Hantaan (hantavirus) viruses, failed to detect any sequence similarity, although the genomic structure of DUG S
RNA is similar to that of the S
RNA segment of Hantaan (HTN) virus.