Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.
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. The genus
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.
Halspiviridae is a family of viruses that consists of a single genus, Salterprovirus, which consists of a single recognised species; Salterprovirus His1. This virus was isolated from hypersaline water in Australia and was able to be cultured on the halophilic archaeon Haloarcula hispanica. Like many other archaeoviruses, His1 has an approximately limoniform (lemon-shaped) virion.
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 in this family: Acidianus two-tailed virus. 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.
Alphafusellovirus is a genus of viruses, in the family Fuselloviridae. Species in the genus Sulfolobus serve as natural hosts. There are seven species in this genus.
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.
Deltalipothrixvirus is a genus of viruses in the family Lipothrixviridae. Archaea acidianus serve as natural hosts. Two species are assigned to the genus.
Gammalipothrixvirus is a genus of viruses in the family Lipothrixviridae. Archaea acidianus serve as natural hosts. There is only one species in this genus: Acidianus filamentous virus 1.
Spiraviridae is a family of 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 Aeropyrum coil-shaped virus (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 positive-sense, single-stranded DNA ( 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 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.
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).
Portogloboviridae is a family of DNA viruses that infect archaea. It is a proposed family of the realm Varidnaviria. Viruses in the family are related to Halopanivirales. The capsid proteins of these viruses and their characteristics are of evolutionary importance for the origin of the other Varidnaviria viruses since they seem to retain primordial characters.
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.
