Notes on Genus: Avihepatovirus

icosahedra

Type member: Duck hepatitis A virus

Contents

• Members of this Genus
• General Description
• Morphology
• Electron Micrograph
• Genome
• Genus Genomic Organization
• Genome Map
• Type Member Genomic Organization
• All Known Sequences
• Curated Sequences

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.

Morphology

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.

Genome

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 kDa	Coat protein VP0
1C	26.7 kDa	Coat protein VP3
1D	26.4 kDa	Coat protein VP1
2A1	2.2 kDa	protease
2A2	32.4 kDa	non-structural protein
2B	13.1 kDa	non-structural protein
2C	38.3 kDa	non-structural protein
3A	10.7 kDa	non-structural protein
3B	3.9 kDa	Genome-linked protein (VPg)
3C	19.7 kDa	protease
3D	51.0 kDa	polymerase