Complete nucleotide sequence and infectious cDNA clone of the RNA1 of a Chinese isolate of broad bean wilt virus 2.

The nucleotide sequence of the RNA1 of broad bean wilt virus 2 (BBWV2) isolate B935 has been determined from overlapping cDNA clones. It contains 5956 nucleotides in length excluding the 3' terminal poly(A) tail and contains a single long open reading frame (ORF) of 5613 nucleotides extending from nucleotide 234 to 5846. A repeated motif has been found in the 5' non-coding region. The predicted polyprotein encoded by the long ORF is 1870 amino acid in length with a molecular weight of 210 K. Amino acid sequence comparisons between portions of the BBWV2 RNA1-encoded polyprotein and proteins encoded by several species in Comoviridae revealed the putative functions of BBWV2 RNA1-encoded proteins and the same general genetic organization as that of comoviruses and nepoviruses. Based on the determined sequence, full-length cDNA clone of RNA1 designated as pU1FL was constructed. Together with transcripts from full-length cDNA clone of RNA2 (pU2FL), transcripts from pU1FL infected Chenopodium quinoa successfully.