Complete genomic sequence of Dracaena mottle virus, a distinct badnavirus.

The genome of Dracaena mottle virus (DrMV) was cloned from infected Dracaena sanderiana plants, and its complete nucleotide sequence was determined and analyzed. The circular DNA genome consists of 7531 base pairs (bp) and possesses seven putative open reading frames (ORFs) on the plus-strand that potentially encode proteins of 17.6, 14.9, 215.0, 11.9, 11.3, 16.1, and 11.0 kDa, respectively. ORF 3, the largest ORF, encodes a putative polyprotein that contains sequences for viral aspartyl proteinase, reverse transcriptase (RT) and ribonuclease H (RNase H), characteristic of pararetroviruses. Phylogenetic analysis based on the amino acid sequence of ORF 3 showed that DrMV is related to other badnaviruses. However, the nucleotide sequence coding for the RT and RNase H domain of DrMV shares less than 68% homology with that of any known badnaviruses. The seventh ORF of DrMV is not found in other badnaviruses described before. Our results strongly support that DrMV is a distinct species of the genus Badnavirus, family Caulimoviridae. Evidence that the DrMV sequence is integrated in the D. sanderiana genome is presented and discussed.