Notes on Genus: Rubivirus

enveloped spheres
enveloped spheres

Type member: Rubella virus

Contents

General Description

This is one of two genera in the family Togaviridae and consists of a single virus that has a genome of <10kb that encodes three structural proteins (coat protein and two membrane proteins). The virus is dispersed in aerosols and is not known to have any insect vector. The name is from the type (and only) member, Rubella virus.

Morphology

Virions enveloped and spherical about 60 nm in diameter and with glycoprotein spikes. There are three structural proteins (coat protein and two membrane proteins).

Genome

Monopartite positive sense single-stranded RNA about 9.7kb in length, with a 5'-cap and a 3'-polyA tail.

Genus Genomic Organization

There are two slightly overlapping polyproteins, the second of which is translated from a subgenomic RNA. They are subsequently processed into a number of functional proteins.

Type Member Genomic Organization

There are two slightly overlapping polyproteins, the second of which is translated from a subgenomic RNA. They are subsequently processed into a number of functional proteins:
  • Non-structural polyprotein (240 kDa):
    • Processing not determined in detail but protease, helicase and replicase motifs have been identified
  • Structural polyprotein (115 kDa):
    • Coat protein C, 33 kDa
    • Envelope protein E2, 30 kDa
    • Envelope protein E1, 52 kDa