Notes on Genus: Panicovirus
Type member: Panicum mosaic virus
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.
Virions isometric (icosahedral), 25-30 nm in diameter.
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 kDa||polymerase|
|2 ||112 kDa||polymerase: readthrough of P1|
|3 ||8 kDa||involved in virus movement|
|4 ||6.6 kDa||involved in virus movement: suggestions of a possible frameshift, extending the product of ORF3 now seem unlikely|
|5 ||26 kDa||coat protein|
|6 ||15 kDa||involved in virus movement|