Totiviridae

Last updated

Totiviridae
Journal.ppat.1003225.g003.A.B.png
Capsid structure of Helminthosporium victoriae virus 190S (HvV190S)
Journal.ppat.1003225.g002.L.T.png
Cryo-EM of HvV190S virions.
Virus classification Red Pencil Icon.png
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Duplornaviricota
Class: Chrymotiviricetes
Order: Ghabrivirales
Family:Totiviridae

Totiviridae is a family of double-stranded RNA viruses. Giardia lamblia, leishmania, trichomonas vaginalis, and fungi serve as natural hosts. The name of the group derives from Latin toti which means undivided or whole. There are 28 species in this family, assigned to 5 genera. [1] [2]

Contents

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 capsid protein and is about 40 nanometers in diameter. [1]

Genome

Genome of family Totiviridae Totiviridae genome.jpg
Genome of family Totiviridae

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

Life cycle of S. cerevisiae virus L-A Journal.ppat.1005890.g001.A.jpg
Life cycle of S. cerevisiae virus L-A

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]

Taxonomy

The family Totiviridae has five genera: [2]

Examples

An example of fungal totivirus is the L-A helper virus, a cytoplasmic virus found primarily in Saccharomyces cerevisiae . [3]

Related Research Articles

<i>Barnaviridae</i> Family of viruses

Barnaviridae is a family of non-enveloped, positive-strand RNA viruses. Cultivated mushrooms serve as natural hosts. The family has one genus, Barnavirus, which contains one species: Mushroom bacilliform virus. Diseases associated with this family includes La France disease.

<i>Potyviridae</i> Family of viruses

Potyviridae is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family has 12 genera and 235 species, three of which are unassigned to a genus.

<i>Tombusviridae</i> Family of viruses

Tombusviridae is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from Tomato bushy stunt virus (TBSV).

<span class="mw-page-title-main">Baltimore classification</span> Virus classification system made by David Baltimore

Baltimore classification is a system used to classify viruses based on their manner of messenger RNA (mRNA) synthesis. By organizing viruses based on their manner of mRNA production, it is possible to study viruses that behave similarly as a distinct group. Seven Baltimore groups are described that take into consideration whether the viral genome is made of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), whether the genome is single- or double-stranded, and whether the sense of a single-stranded RNA genome is positive or negative.

<i>Cypovirus</i> Genus of viruses

Cypovirus, short for cytoplasmic polyhedrosis virus, is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Cypoviruses have only been isolated from insects. Diseases associated with this genus include chronic diarrhoea and pale blue iridescence in the guts of larvae. Sixteen species are placed in this genus.

<i>Totivirus</i> Genus of viruses

Totivirus is a genus of double-stranded RNA viruses in the family Totiviridae. Fungi serve as natural hosts. The name of the group derives from Latin toti which means undivided or whole. There are seven species in this genus.

<i>Partitiviridae</i> Family of viruses

Partitiviridae is a family of double-stranded RNA viruses. Plants, fungi, and protozoa serve as natural hosts. It has been suggested that they can also infect bacteria. The name comes from the Latin partitius, which means divided, and refers to the segmented genome of partitiviruses. There are five genera and 60 species in the family, 15 of which are unassigned to a genus.

Luteovirus is a genus of viruses, in the family Tombusviridae. There are 13 species in this genus. Plants serve as natural hosts. The geographical distribution of Luteoviruses is widespread, with the virus primarily infecting plants via transmission by aphid vectors. The virus only replicates within the host cell and not within the vector. The name 'luteovirus' arises from the Latin luteus, which is translated as 'yellow'. Luteovirus was given this name due to the symptomatic yellowing of the plant that occurs as a result of infection.

<span class="mw-page-title-main">Double-stranded RNA viruses</span> Type of virus according to Baltimore classification

Double-stranded RNA viruses are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA polymerase (RdRp). The positive-strand RNA may be used as messenger RNA (mRNA) which can be translated into viral proteins by the host cell's ribosomes. The positive-strand RNA can also be replicated by the RdRp to create a new double-stranded viral genome.

<i>Sobemovirus</i> Genus of viruses

Sobemovirus is a genus of viruses. Plants serve as natural hosts. There are 20 species in this genus. Diseases associated with this genus include: mosaics and mottles.

Endornaviridae is a family of viruses. Plants, fungi, and oomycetes serve as natural hosts. There are 31 species in this family, assigned to 2 genera. Members of Alphaendornavirus infect plants, fungi and the oomycete Phytophthora sp., members of Betaendornavirus infect ascomycete fungi.

Hypovirus is a genus of viruses, in the family Hypoviridae. Fungi serve as natural hosts. There are four species in this genus. Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control.

<i>Picobirnavirus</i> Genus of viruses

Picobirnavirus is a genus of double-stranded RNA viruses. It is the only genus in the family Picobirnaviridae. Although amniotes, especially mammals, were thought to serve as hosts, it has been recently suggested that these viruses might infect bacteria and possibly some other invertebrates. There are three species in this genus. Associated symptoms include gastroenteritis in animals and humans, though the disease association is unclear.

<i>Leishmaniavirus</i> Genus of viruses

Leishmaniavirus is a genus of double-stranded RNA virus, in the family Totiviridae. Protozoa serve as natural hosts, and Leishmaniaviruses are present in several species of the human protozoan parasite Leishmania. There are two species in this genus.

<span class="mw-page-title-main">Giardiavirus</span> Genus of viruses

Giardiavirus is a genus of viruses, in the family Totiviridae. Protozoa serve as natural hosts. There is only one species in this genus: Giardia lamblia virus.

Mitovirus is a genus of positive-strand RNA viruses, in the family Mitoviridae. Fungi serve as natural hosts. There are five species in the genus.

<i>Mycoreovirus</i> Genus of viruses

Mycoreovirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Fungi serve as natural hosts. Diseases associated with this genus include: hypovirulence of the fungal host. The name of the group derives from Ancient Greek myco which means fungus. There are three species in this genus.

<i>Victorivirus</i> Genus of viruses

Victorivirus is a genus of viruses, in the family Totiviridae. Filamentous fungi serve as natural hosts. There are 14 species in this genus.

<i>Megabirnaviridae</i> Family of viruses

Megabirnaviridae is a family of double-stranded RNA viruses with one genus Megabirnavirus which infects fungi. The group name derives from member's bipartite dsRNA genome and mega that is greater genome size than families Birnaviridae and Picobirnaviridae. There is only one species in this family: Rosellinia necatrix megabirnavirus 1. Diseases associated with this family include: reduced host virulence.

<i>Trichomonasvirus</i> Genus of viruses

Trichomonasvirus is a genus of viruses, in the family Totiviridae. The protozoan parasite Trichomonas vaginalis serves as the natural host. There are four species in this genus.

References

  1. 1 2 3 4 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. 1 2 "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 13 May 2021.
  3. Rodríguez-Cousiño, Nieves; Esteban, Rosa (9 December 2016). "Analysis of L-A-2, the helper virus of K2 killer toxin-encoding M2 dsRNA, and of L-BC variants from wine yeast strain populations provides new insights into the relationship and evolution of dsRNA viruses of yeast" (PDF). Appl. Environ. Microbiol. 83 (4). doi:10.1128/AEM.02991-16. PMC   5288835 . PMID   27940540 via aem.asm.org.