Notes on Genus: Sequivirus

icosahedra

Type member: Parsnip yellow fleck virus

Contents

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

General Description

This is one of the genera in the plant picornavirus family Secoviridae and is also known as the parsnip yellow fleck virus group. Members of the genus are dependent for aphid transmission on a helper protein encoded by a separate helper virus. The name is derived from the Latin sequi, to follow or accompany, to describe this dependent transmission. The helper virus for the type member, parsnip yellow fleck virus, is anthriscus yellows waikavirus.

Morphology

Virions isometric (icosahedral) about 30 nm in diameter with no obvious structural features.

Genome

Monopartite, single-stranded positive-sense RNA about 10,000 nucleotides long. 3' terminus has no poly(A) tract. 5' terminus probably has a genome-linked protein (VPg).

Genus Genomic Organization

The sole (or major) translation product is a polyprotein, which is subsequently processed into a number of products, including three coat proteins.

Type Member Genomic Organization

The sole (or major) translation product is a polyprotein, in which several products or domains have been identified:
P1 c. 40 kDa      Unknown function
CP1 22.5 kDacoat protein 1
CP226 kDa coat protein 2
CP3 31 kDacoat protein 3
Pro? Protease domain
Pol ?Polymerase domain
NTP? NTP-binding domain