Notes on Genus: Bidensovirus

icosahedra
icosahedra

Type member: Bombyx mori bidensovirus

Contents

General Description

The genus Bidensovirus is the only genus in the family Bidnaviridae. It contains invertebrate viruses that were once considered members of the family Parvoviridae (subfamily Densovirinae) but have bipartite genomes of a much larger size, two different structural proteins and differences in coding strategy.

Morphology

Virions are isometric (icosahedral), not enveloped and about 25 nm in diameter. There are two structural proteins.

Genome

There are two linear ssDNA segments of about 6 and 6.5 kb, that are packaged separately. The complementary strands are also packaged, so that there are 4 different types of full particles.

Genus Genomic Organization

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

Type Member Genomic Organization

  • DNA1 (6.5 kb) encodes the capsid protein VP1 (128 kDa) on one strand and three non-structural proteins (NS1 of 14 kDa, NS2 of 37 kDa and NS3 of 55 kDa) on the complementary strand.
  • DNA2 (6 kb) encodes the capsid protein VP2 (133 kDa) on one strand and the non-structural protein NS4 (27 kDa) on the complementary strand.