| Alphafusellovirus | |
|---|---|
Virus classification  | |
| (unranked): | Virus |
| Family: | Fuselloviridae |
| Genus: | Alphafusellovirus |
| Synonyms | |
| |
Alphafusellovirus is a genus of viruses, in the family Fuselloviridae . Species in the genus Sulfolobus ( Sulfolobus shibatae , Sulfolobus solfataricus , and Sulfolobus islandicus) serve as natural hosts. There are seven species in this genus. [1] [2]
The genus contains the following species: [2]
Viruses in Alphafusellovirus are enveloped, with lemon-shaped geometries. The diameter is around 60 nm, with a length of 100 nm. Genomes are circular, around 17.3kb in length. [1] Biochemical characterization of SSV1, the type species of the Alphafusellovirus genus, showed that virions are composed of four virus-encoded structural proteins, VP1 to VP4, as well as one DNA-binding chromatin protein of cellular origin. The virion proteins VP1, VP3, and VP4 undergo posttranslational modification by glycosylation, seemingly at multiple sites. VP1 is also proteolytically processed. SSV1 virions contain glycerol dibiphytanyl glycerol tetraether (GDGT) lipids, which appear to be acquired by the virus in a selective manner from the host cytoplasmic membrane. [3]
| Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
|---|---|---|---|---|---|
| Alphafusellovirus | Lemon-shaped | Enveloped | Circular | Monopartite |
Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell. DNA-templated transcription is the method of transcription. Sulfolobus shibatae, sulfolobus solfataricus, and sulfolobus islandicus serve as the natural host. [1] It has been demonstrated that SSV1, the type species of the genus, is released from the host without causing cell lysis by a budding mechanism, similar to that employed by enveloped eukaryotic viruses. [4]
| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
|---|---|---|---|---|---|---|---|
| Alphafusellovirus | Archea: thermolophilic | None | Injection | Budding | Cytoplasm | Cytoplasm | Passive diffusion |
Birnaviridae is a family of double-stranded RNA viruses. Salmonid fish, birds and insects serve as natural hosts. There are currently 11 species in this family, divided among seven genera. Diseases associated with this family include infectious pancreatic necrosis in salmonid fish, which causes significant losses to the aquaculture industry, with chronic infection in adult salmonid fish and acute viral disease in young salmonid fish.
Icerudivirus is a genus of viruses in the family Rudiviridae. These viruses are non-enveloped, stiff-rod-shaped viruses with linear dsDNA genomes, that infect hyperthermophilic archaea of the species Sulfolobus islandicus. There are three species in the genus.
Lipothrixviridae is a family of viruses in the order Ligamenvirales. Thermophilic archaea in the phylum Thermoproteota serve as natural hosts. There are 11 species in this family, assigned to 4 genera.
Corticovirus is a genus of viruses in the family Corticoviridae. Corticoviruses are bacteriophages; that is, their natural hosts are bacteria. The genus contains two species. The name is derived from Latin cortex, corticis. However, prophages closely related to PM2 are abundant in the genomes of aquatic bacteria, suggesting that the ecological importance of corticoviruses might be underestimated. Bacteriophage PM2 was first described in 1968 after isolation from seawater sampled from the coast of Chile.
Fuselloviridae is a family of viruses. Sulfolobus species, specifically shibatae, solfataricus, and islandicus, serve as natural hosts. There are two genera and nine species in the family. The Fuselloviridae are ubiquitous in high-temperature (≥70 °C), acidic hot springs around the world.
Guttaviridae is a family of viruses. Archaea serve as natural hosts. There are two genera in this family, containing one species each. The name is derived from the Latin gutta, meaning 'droplet'.
Globuloviridae is a family of hyperthermophilic archaeal viruses. Crenarchaea of the genera Pyrobaculum and Thermoproteus serve as natural hosts. There are four species in this family, assigned to a single genus, Alphaglobulovirus.
Bottigliavirus is the only genus in the family Ampullaviridae and contains 3 species. Ampullaviridae infect archaea of the genus Acidianus. The name of the family and genus is derived from the Latin word for bottle, ampulla, due to the virions having the shape of a bottle. The family was first described during an investigation of the microbial flora of hot springs in Italy.
Bicaudaviridae is a family of hyperthermophilic archaeal viruses. Members of the genus Acidianus serve as natural hosts. There is only one genus, Bicaudavirus, and one species, Acidianus two-tailed virus, in this family. However, Sulfolobus tengchongensis spindle-shaped viruses 1 and 2 are regarded to belong to this family also.
Clavaviridae is a family of double-stranded viruses that infect archaea. This family was first described by the team led by D. Prangishvili in 2010. There is one genus in this family (Clavavirus). Within this genus, a single species has been described to date: Aeropyrum pernix bacilliform virus 1 (APBV1).
David Prangishvili is a virologist, Professor at the Pasteur Institute of Paris, and foremost authority on viruses infecting Archaea.
Yingchengvirus is a genus of double stranded DNA viruses that infect haloarchaea. The genus was previously named Betasphaerolipovirus.
Alphaguttavirus is a genus of viruses, in the family Guttaviridae. Sulfolobus newzealandicus serve as natural hosts. There is only one species in this genus: Sulfolobus newzealandicus droplet-shaped virus.
Tristromaviridae is a family of viruses. Archaea of the genera Thermoproteus and Pyrobaculum serve as natural hosts. Tristromaviridae is the sole family in the order Primavirales. There are two genera and three species in the family.
Spiraviridae is a family of incertae sedis viruses that replicate in hyperthermophilic archaea of the genus Aeropyrum, specifically Aeropyrum pernix. The family contains one genus, Alphaspiravirus, which contains one species, Aeropyrum coil-shaped virus. The virions of ACV are non-enveloped and in the shape of hollow cylinders that are formed by a coiling fiber that consists of two intertwining halves of the circular DNA strand inside a capsid. An appendage protrudes from each end of the cylindrical virion. The viral genome is ssDNA(+) and encodes for significantly more genes than other known ssDNA viruses. ACV is also unique in that it appears to lack its own enzymes to aid replication, instead likely using the host cell's replisomes. ACV has no known relation to any other archaea-infecting viruses, but it does share its coil-like morphology with some other archaeal viruses, suggesting that such viruses may be an ancient lineage that only infect archaea.
Sulfolobus tengchongensis spindle-shaped virus 1 (STSV1) is a DNA virus of the family Bicaudaviridae. It infects the hyperthermophilic archaeon Sulfolobus tengchongensis which can be found in the volcanic area of Tengchong, Baoshan City, in western Yunnan province, People's Republic of China.
Sulfolobus islandicus rod-shaped virus 2, also referred to as SIRV2, is an archaeal virus whose only known host is the archaeon Sulfolobus islandicus. This virus belongs to the family Rudiviridae. Like other viruses in the family, it is common in geothermal environments.
Sulfolobus islandicus filamentous virus (SIFV) is an archaeal virus, classified in the family Lipothrixviridae within the order Ligamenvirales. The virus infects hypethermophilic and acidophilic archaeon Sulfolobus islandicus.
An archaeal virus is a virus that infects and replicates in archaea, a domain of unicellular, prokaryotic organisms. Archaeal viruses, like their hosts, are found worldwide, including in extreme environments inhospitable to most life such as acidic hot springs, highly saline bodies of water, and at the bottom of the ocean. They have been also found in the human body. The first known archaeal virus was described in 1974 and since then, a large diversity of archaeal viruses have been discovered, many possessing unique characteristics not found in other viruses. Little is known about their biological processes, such as how they replicate, but they are believed to have many independent origins, some of which likely predate the last archaeal common ancestor (LACA).
Adnaviria is a realm of viruses that includes archaeal viruses that have a filamentous virion and a linear, double-stranded DNA genome. The genome exists in A-form (A-DNA) and encodes a dimeric major capsid protein (MCP) that contains the SIRV2 fold, a type of alpha-helix bundle containing four helices. The virion consists of the genome encased in capsid proteins to form a helical nucleoprotein complex. For some viruses, this helix is surrounded by a lipid membrane called an envelope. Some contain an additional protein layer between the nucleoprotein helix and the envelope. Complete virions are long and thin and may be flexible or a stiff like a rod.