Notes on Genus: Enterovirus

icosahedra

Type member: Human enterovirus C

Contents

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

General Description

The genus Enterovirus (from the greek enteron = intestine) is one of the genera in the family Picornaviridae. Genome organisation is fairly conserved within the family but members of this genus have a 5'-UTR which has no polyC tract, there is no leader protein and the 2A protein is a protease. Species previously classified in the genus Rhinovirus have recently been moved into this genus.

Morphology

Virions isometric (icosahedral), not enveloped 30 nm in diameter, made of 60 units (protomers) each consisting of one molecule of each of three surface coat proteins and with a fourth internal capsid protein. The virions have more surface features than most other picornaviruses, with a raised area at the fivefold axis surounded by a groove into which the host cellular receptor binds.

Genome

Monopartite positive sense single-stranded RNA 7.3-7.4 kb in length. There is a genome-linked protein (VPg) at the 5'-terminus and a 3'-polyA tail.

Genus Genomic Organization

The RNA encodes a single polyprotein that is subsequently processed into the functional products. The major structural proteins are encoded near the N-terminus.

Type Member Genomic Organization

The genome of about 7,400 nucleotides is translated into a single polyprotein, which is subsequently processed into eleven products:
1A  7.5 kDaCoat protein VP4 (internal capsid protein)
1B  30.0 kDaCoat protein VP2 (surface capsid protein)
1C 26.4 kDaCoat protein VP3 (surface capsid protein)
1D 33.5 kDaCoat protein VP1 (surface capsid protein)
2A 16.7 kDaprotease
2B 10.7 kDanon-structural protein
2C 37.6 kDanon-structural protein
3A 9.8 kDanon-structural protein
3B 2.4 kDaGenome-linked protein (VPg)
3C 19.7 kDaprotease
3D 52.5 kDapolymerase