Notes on Family: Roniviridae

enveloped bacilliform

Contents

Members of this Family
General Description
Morphology
Genome
Genera in the Family
All Known Sequences
Curated Sequences

General Description

This family is grouped with the Coronaviridae, Mesoniviridae and Arteriviridae 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. Members of the family Roniviridae infect crustaceans and are distinguished by their bacilliform particles (hence the name rod-shaped nidovirus). Members of the family Arteriviridae have spherical virions 45-60nm in diameter, while those of the family Coronaviridae are more than 100nm, and all infect mammals.

Morphology

Virions enveloped and bacilliform, 150-200 nm x 40-60 nm.

Genome

Monopartite positive sense single-stranded RNA of size about 26kb 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 about 4 other genes, 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: