Notes on Family: Arteriviridae
enveloped spheres
Contents
General Description
This family is grouped with the
Coronaviridae,
Mesoniviridae and
Roniviridae to form the order
Nidovirales. All members of the order have enveloped particles containing a single species of single-stranded RNA that encodes for a number of proteins by means of a series of nested (Latin
Nido = nest) subgenomic RNAs. The family
Arteriviridae contains those members with spherical virions 45-60nm in diameter (those of the family
Coronaviridae are more than 100nm) and which infect mammals. The newly created family
Roniviridae consists of viruses with bacilliform particles that infect crustaceans.
Morphology
Virions enveloped and spherical 45-60 nm in diameter.
Genomen
Monopartite positive sense single-stranded RNA of size 12-16kb and with a 3'-polyA tail. Two large, overlapping ORFs at the 5'-end of the genome encode the major non-structural proteins and are expressed as a fusion protein by ribosomal frameshift. Downstream are up to 9 other genes, mostly or entirely encoding structural proteins, and these are expressed from a 3'-coterminal nested set of subgenomic RNAs.
Genera in the Family
There is currently only one genus:
