Notes on Genus: Avihepatovirus


Type member: Duck hepatitis A virus


General Description

The genus Avihepatovirus (from avian and hepato=liver) is one of the genera in the family Picornaviridae. Genome organisation is fairly conserved within the family but members of this genus have two separate motifs characteristic of the 2A protein and a longer 3'-UTR than other members of the family.


Virions isometric (icosahedral), not enveloped 30 nm in diameter, made of 60 units (protomers) each consisting of one molecule of each of three surface coat proteins and with a fourth internal capsid protein.


Monopartite positive sense single-stranded RNA about 8.kb in length. There is a genome-linked protein (VPg) at the 5'-terminus and a 3'-polyA tail.

Genus Genomic Organization

The RNA encodes a single polyprotein that is subsequently processed into the functional products. The major structural proteins are encoded at the N-terminus.

Type Member Genomic Organization

The genome of about 7,300 nucleotides is translated into a single polyprotein, which is subsequently processed into eleven products:
1B  28.2 kDaCoat protein VP0
1C 26.7 kDaCoat protein VP3
1D 26.4 kDaCoat protein VP1
2A12.2 kDaprotease
2A2 32.4 kDanon-structural protein
2B 13.1 kDanon-structural protein
2C 38.3 kDanon-structural protein
3A 10.7 kDanon-structural protein
3B 3.9 kDaGenome-linked protein (VPg)
3C 19.7 kDaprotease
3D 51.0 kDapolymerase