Notes on Genus: Cripavirus

icosahedra

Type member: Cricket paralysis virus

Contents

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

General Description

This genus, formerly known as the Cricket paralysis-like viruses, is one of two genera of insect-infecting viruses in the family Dicistroviridae. The genomes have two polyproteins encoded on a single RNA but in other respects they are similar to those of the plant- and vertebrate-infecting viruses that make up the picornavirus "superfamily", which includes the families Secoviridae, Potyviridae and Picornaviridae. There are also similarities to the family Caliciviridae. It differs from the sister genus Aparavirus in the sequence and structure of the internal ribosome entry site (IRES) at the intergenic region (IGR) and members of the two genera are phylogenetically distinct.

Morphology

Virions isometric (icosahedral), not enveloped, about 30 nm in diameter.

Genome

Monopartite positive sense single-stranded RNA 8.5-10.2 kb in length with a genome-linked protein (VPg) at the 5'-terminus and a 3'-polyA tail.

Genus Genomic Organization

The RNA encodes two polyproteins, the first of which has the domains of the non-structural proteins (helicase, protease and replicase) while the second consists of the (three or more) coat proteins. There is an internal ribosome entry site (IRES) at the intergenic region (IGR) between the two ORFs.

Type Member Genomic Organization

The genome of about 9,100 nucleotides is predicted to be translated into:
  1. Non-structural polyprotein (203.8 kDa) with (from N- to C- termini) helicase protease and polymerase domains
  2. Structural polyprotein (100.3 kDa) that is processed into at least three coat proteins