Totiviridae
| Totiviridae | |
|---|---|
| |
| Capsid structure of Helminthosporium victoriae virus 190S (HvV190S) | |
| |
virions .
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Virus classification 
| |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Duplornaviricota |
| Class: | Chrymotiviricetes |
| Order: | Ghabrivirales |
| Family: | Totiviridae |
Totiviridae is a family of
Structure
Viruses in the family Totiviridae are non-enveloped, double-stranded RNA viruses with icosahedral geometries, and T=2 symmetry. The virion consists of a single
Genome
The genome is composed of a monopartite, linear double-stranded RNA molecule of 4.6–6.7 kilobases. It contains two overlapping open reading frames (ORF) – gag and pol – which respectively encode the capsid protein and the RNA-dependent RNA polymerase. Some totiviruses contain a third small potential ORF.[1]
Life cycle
Viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. Translation takes place by -1 ribosomal frameshifting, +1 ribosomal frameshifting, viral initiation, and RNA termination-reinitiation. The virus exits the host cell by cell-to-cell movement. Giardia lamblia protozoa, leishmania protozoa, protozoan trichomonas vaginalis, and fungi serve as the natural host.[1]
| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
|---|---|---|---|---|---|---|---|
| Giardiavirus | Protozoa | None | Cell receptor endocytosis | Exocytosis | Cytoplasm | Cytoplasm | Passive diffusion |
| Leishmaniavirus | Protozoa: leishmania | None | Cell receptor endocytosis | Cell division | Cytoplasm | Cytoplasm | Cell division |
| Totivirus | Fungi: saccharomyces cerevisiae; fungi: smut fungi | None | Cytoplasmic exchange, sporogenesis; hyphal anastomosis | Cytoplasmic exchange, sporogenesis; hyphal anastomosis | Cytoplasm | Cytoplasm | Cell division; sporogenesis; cell fusion |
| Victorivirus | Fungi | None | Unknown | Unknown | Cytoplasm | Cytoplasm | Unknown |
| Trichomonasvirus | Protozoa | Endocytosis | Unknown | Unknown | Cytoplasm | Cytoplasm | Unknown |
Taxonomy
The family Totiviridae has five genera:[2]
Examples
An example of fungal totivirus is the
References
- ^ a b c d "Viral Zone". ExPASy. Retrieved 15 June 2015.
- ^ a b "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 13 May 2021.
- PMID 27940540– via aem.asm.org.