Bidensovirus

Bidensovirus is a genus of single stranded DNA viruses that infect invertebrates. The species in this genus were originally classified in the family Parvoviridae (subfamily Densovirinae) but were moved to a new genus because of significant differences in the genomes.^[1]

Virology

The virons are icosahedral, non enveloped and ~25 nanometers in diameter. They contain two structural proteins.

The genome is bipartate with two linear segments of ~6 and 6.5 kilobases. These segments and the complementary strands are that are packaged separately giving rise to 4 different types of full particles.

Both segments have an ambisense organization, coding for a structural protein in one sense and the non-structural proteins on the complementary strand.

DNA1—the larger segment of 6.5 kb—encodes the capsid protein VP1 (128 kiloDaltons) on one strand and three non-structural proteins—NS1 of 14 kiloDaltons (kDa), NS2 of 37 kDa and NS3 of 55 kDa—on the complementary strand.

DNA2—the smaller segment of 6 kb—encodes the capsid protein VP2 (133 kDa) on one strand and the non-structural protein NS4 (27 kDa) on the complementary strand.

The open reading frame 4 is 3318 nucleotide in length and encodes a predicted 1105 amino acid protein which has a conserved DNA polymerase motif. It appears to encode at least 2 other proteins including one of ~53 kiloDaltons (kDa) that forms part of the viron.^[2]

Taxonomy

There is one species in this genus currently recognised—Bombyx mori bidensovirus.

References