Notes on Genus: Cystovirus
Type member: Pseudomonas phage f6
This is the only genus in the family Cystoviridae
. These are the only phage with dsRNA genomes.
Virions are spherical, about 85 nm in diameter, with an envelope and covered by spikes.
There are 3 linear segments of dsRNA of 6-7, 4-4.2 and 2.3-3 kbp.
Genus Genomic Organization
Each segment encodes four proteins. Proteins forming the polymerase complex are encoded on the largest segment, RNA-L. Absorption and fusion proteins that form the virion envelope are encoded on RNA-M, while proteins of the nucleocapsid core are encoded on the smallest segment, RNA-S.
Type Member Genomic Organization
The proteins encoded by the genome in their order in each segment are:
|6||17.3||Membrane anchor protein|
|S||8||16.0||Nucleocapsid surface protein|
|9||9.6||Membrane assembly protein|
|5||24.1 or 23.3||Endopeptidase|