Totivirus

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Totivirus
Viruses-10-00481-g002.A.B.png
ScV-L-A capsid protein structure and homodimer of the gag capsid protei
Virus classification Red Pencil Icon.png
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Duplornaviricota
Class: Chrymotiviricetes
Order: Ghabrivirales
Family: Totiviridae
Genus:Totivirus
Synonyms [1]
  • Saccharomyces cerevisiae virus group

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. [2] [3]

Contents

Structure

Viruses in the genus Totivirus are non-enveloped, with icosahedral symmetry, and T=2 architecture. The diameter is around 40 nm. [2]

Genome

Genome of genus totivirus Totiviridae genome.jpg
Genome of genus totivirus

Totiviruses have a genome of 4700–6700 nucleotides in length and only a single copy of the genome is present in the particle. The nucleic acid content of a totivirus capsid is usually of one segment but can also contain three or four segments of linear double stranded RNA. The genome contains two large overlapping open reading frames (ORFs). These open reading frames (ORFs) code for a capsid protein (CP) and an RNA-dependent RNA polymerase (RdRp). The 5' end of the positive strand of the dsRNA genome has no cap and is very structured. Totiviruses contain a long 5' untranslated region (5' UTR) which functions as an internal ribosome entry site (IRES). Totiviruses can have satellite RNAs encoding a toxin.[ citation needed ]

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. Entry into the host cell is achieved by virus remains intracellular. 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. The virus exits the host cell by cell-to-cell movement. Fungi Saccharomyces cerevisiae and smut serve as the natural host. The virus is transmitted during cell division, sporogenesis, and cell fusion. [2]

Taxonomy

The genus Totivirus contains the member species: [3]

Related Research Articles

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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.

<i>Barnaviridae</i> Family of viruses

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<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.

<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.

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.

Gammaflexiviridae is a family of viruses in the order Tymovirales. Fungi serve as natural hosts. There is only one genus in the family, Mycoflexivirus, which has one species: Botrytis virus F.

Cripavirus is a genus of viruses in the order Picornavirales, in the family Dicistroviridae. Invertebrates serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: DCV: increased reproductive potential; extremely pathogenic when injected with high associated mortality; CrPV: paralysis and death. These viruses can produce proteins directly from their RNA genome upon entering a cell; and therefore, does not require an RNA polymerase packaged in with it, as this may be produced from the genome after entering the cell. The name of the cripavirus family originates from its most famous member the Cricket Paralysis Virus. Which was made famous by its rather unusual IRES : the Cripavirus IRES. The Cripavirus IRES is an RNA element that allows the virus to bind the ribosome and translate without a need for any initiation factors – as initiation is the most regulated step of translation this allows the virus to avoid many mechanisms to inhibit viral activity.

<i>Avibirnavirus</i> Genus of viruses

Avibirnavirus is a genus of viruses in family Birnaviridae. There is a single species in this genus: Infectious bursal disease virus, which infects chickens and other fowl. It causes severe inflammation of the bursa of Fabricius, and causes considerable morbidity and mortality.

Idnoreovirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Hymenoptera insects serve as natural hosts. The genus name is an acronym for insect derived non occluded reovirus. There are five species in this genus.

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.

Narnavirus is a genus of positive-strand RNA viruses in the family Narnaviridae. Fungi serve as natural hosts. There are two species in this genus. Member viruses have been shown to be required for sexual reproduction of Rhizopus microsporus. Narnaviruses have a naked RNA genome without a virion and derive their name from this feature.

<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.

<span class="mw-page-title-main">Quadriviridae</span> Family of viruses

Quadriviridae is a family of double-stranded RNA viruses with a single genus Quadrivirus. 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.

Bacillarnavirus is a genus of viruses in the order Picornavirales. Marine diatoms serve as natural hosts. There are three species in this genus.

Cardoreovirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Sedoreovirinae. Crabs serve as natural hosts. There is only one species in this genus: Eriocheir sinensis reovirus. Diseases associated with this genus include: trembling disease. The name derives from Latin words "carcinus" which means crab and "doeca" which means twelve in reference to the number genome segments.

Dicipivirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Dog serve as natural hosts. There are two species in this genus.

<i>Dinovernavirus</i> Genus of viruses

Dinovernavirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Member viruses replicate in a variety of mosquito cell lines. The name is an abbreviation for double-stranded, insect, novem, rna virus. There is one species in the genus: Aedes pseudoscutellaris reovirus.

References

  1. "MINUTES OF THE SIXTH MEETING OF THE ICTV, SENDAI, 5th SEPTEMBER 1984" (PDF). International Committee on Taxonomy of Viruses (ICTV). 5 September 1984. Retrieved 11 February 2020.
  2. 1 2 3 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  3. 1 2 "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 13 May 2021.