Notes on Genus: Hepacivirus

icosahedra

Type member: Hepatitis C virus

General Description

This is one of the genera in the family Flaviviridae and contains viruses with a genome of <10kb that encodes three structural proteins (coat protein and two membrane proteins). The only known natural host is man and they are transmitted through infected blood. The genus is named after the type member, Hepatitis C virus.

Morphology

Virions enveloped and spherical about 50 nm in diameter. Mature virions contain two virus-encoded membrane proteins (E1 and E2) in addition to the coat protein.

Genome

Monopartite positive sense single-stranded RNA about 9.6kb in length, with no 3'-polyA tail.

Genus Genomic Organization

There is a single polyprotein of about 330 kDa that is subsequently processed into a number of structural and non-structural proteins. As in other members of the family, the structural proteins are at the N-terminus of the polyprotein.

Type Member Genomic Organization

There is a single polyprotein of about 330 kDa that is subsequently processed into a number of structural and non-structural proteins:

Coat protein C, 20.7 kDa
Envelope glycoprotein E1, 20.8 kDa
Envelope glycoprotein E2, 40.2 kDa
p7 protein, 6.7 kDa of unknown function incompletely cleaved from an E2-p7 precursor
Non-structural protein 2, 23.9 kDa
Non-structural protein 3, 67.2 kDa
Non-structural protein 4a, 5.8 kDa
Non-structural protein 4b, 27.3 kDa
Non-structural protein 5a, 48.7 kDa
Non-structural protein 5b (polymerase), 65.8 kDa