Notes on Family: Permutotetraviridae
icosahedra
Contents
General Description
This family consists of ssRNA viruses with 40nm isometric particles and that infect insects. The name is derived from the Greek
tettares = four, because of the T=4 symmetry of the virions. All tetraviruses were formerly classified in a single family but 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).
Morphology
Virions isometric (icosahedral), not enveloped, about 40 nm in diameter with T=4 icosahedral shell quasi-symmetry.
Genomen
Monopartite positive sense single-stranded RNA of 5.5-6.0 kb without a 3'-polyA tail. There are two major ORFs, one encoding an RNA polymerase and the other a coat protein precursor.
Genera in the Family
There is currently only one genus:
