Notes on Genus: Alphapermutotetravirus
Type member: Thosea asigna virus
This is the first, and currently the only, genus in the family Permutotetraviridae
and consists of viruses previously included in a single family of tetraviruses.This has now been split because of large differences in the types of RNA polymerase and other genome differences. In this family, viruses have highly structured genome terminal sequences and an RdRp domain with a permuted active site and VPg signal similar to members of the family Birnaviridae
Virions isometric (icosahedral), not enveloped, about 40 nm in diameter with T=4 icosahedral shell quasi-symmetry.
Monopartite positive sense single-stranded RNA of 5.5-6.0 kb without a 3'-polyA tail.
Genus Genomic Organization
There are two major ORFs, one encoding an RNA polymerase of about 140 kDa and the other a coat protein precursor of 82-83 kDa that is cleaved to produce structural proteins of about 59 and 7 kDa.
Type Member Genomic Organization
There are two major ORFs. One encodes an RNA polymerase of 140 kDa and the other a coat protein precursor of 82 kDa that is cleaved to produce structural proteins of 58 and 7 kDa.