Notes on Genus: Panicovirus

icosahedra

Type member: Panicum mosaic 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

The genus Panicovirus (from Panicum mosaic virus, the type member) is one of 11 genera in the family Tombusviridae. All the genera are morphologically similar, with icosahedral particles and small, (usually) monopartite ss RNA genomes. The genome and coat protein sizes are similar to those of the genus Machlomovirus, but there are differences in genome organisation and translation strategy.

Morphology

Virions isometric (icosahedral), 25-30 nm in diameter.

Genome

Monopartite, linear, single stranded positive sense RNA about 4300 nucleotides long. 3' terminus has no poly(A) tract.

Genus Genomic Organization

Six open reading frames have been identified. ORFs 1 and 2 (probably a readthrough of 1) are believed to encode a polymerase. Four further ORFs, including one for the coat protein (ORF5) are translated from a single subgenomic RNA.

Type Member Genomic Organization

The RNA is translated by means of several open reading frames (ORFs) into 6 products:
1 48 kDapolymerase
2 112 kDapolymerase: readthrough of P1
3 8 kDainvolved in virus movement
4 6.6 kDainvolved in virus movement: suggestions of a possible frameshift, extending the product of ORF3 now seem unlikely
5 26 kDacoat protein
6 15 kDainvolved in virus movement