Quadrivirus | |
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(Left) Electron micrographs of the Rosellinia necatrix quadrivirus 1, bar = 50 nm. (Right) Three-dimensional cryo-electron microscopy reconstruction of RnQV1 virions at 8Å resolution. | |
Virus classification ![]() | |
(unranked): | Virus |
Realm: | Riboviria |
Kingdom: | Orthornavirae |
Phylum: | Duplornaviricota |
Class: | Chrymotiviricetes |
Order: | Ghabrivirales |
Family: | Quadriviridae |
Genus: | Quadrivirus |
Quadriviridae is a family of double-stranded RNA viruses with a single genus Quadrivirus.[1] The fungi Rosellinia necatrix serves as a natural host. The name of the group derives from the quadripartite genome of its members where in Latin quad means four. There is only one species in this family: Rosellinia necatrix quadrivirus 1.[2][3]
Structure
![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/93/Quadriviridae_virion.jpg/220px-Quadriviridae_virion.jpg)
Mycoviruses in the family Quadriviridae have a non-enveloped isometric capsid which consists of 60 copies of heterodimers of the structural proteins P2 and P4. The diameter of the capsid is around 48 nm.[2][3]
Genome
![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/ODR.Quadri.fig3.v4.png/220px-ODR.Quadri.fig3.v4.png)
Family member genomes are composed of double-stranded RNA. They are divided in to four segments which each code for a protein. The length of the different segments are between 3.5 and 5.0 kbp. The total genome is around 16.8 kbp. Inside the capsid with the genome there is also the RNA-dependent RNA polymerase.[2][3]
Life cycle
Quadriviruses are transmitted internally. They are propagated during cell division and hyphal anastomosis. Viral replication occurs in the cytoplasm. It follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. The fungi Rosellinia necatrix serves as a natural host.[2][3]
Taxonomy
![](https://upload.wikimedia.org/wikipedia/commons/thumb/3/34/ODR.Quadri.Fig4.png-640x480.png/220px-ODR.Quadri.Fig4.png-640x480.png)
The family Quadrivirdae has one genus Quadrivirus which contains the species:[4]
- Rosellinia necatrix quadrivirus 1
References
- ^ Chiba, S; Castón, JR; Ghabrial, SA; Suzuki, N; Ictv Report, Consortium (November 2018). "ICTV Virus Taxonomy Profile: Quadriviridae". The Journal of General Virology. 99 (11): 1480–1481. doi:10.1099/jgv.0.001152. PMID 30265238.
- ^ a b c d "ICTV Report Quadriviridae".
- ^ a b c d e "Viral Zone". ExPASy. Retrieved 13 August 2015.
- ^ "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 13 May 2021.