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.
Geminiviridae is a family of plant viruses that encode their genetic information on a circular genome of single-stranded (ss) DNA. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosaic, yellow mottle, leaf curling, stunting, streaks, reduced yields. They have single-stranded circular DNA genomes encoding genes that diverge in both directions from a virion strand origin of replication. According to the Baltimore classification they are considered class II viruses. It is the largest known family of single stranded DNA viruses.
Mardivirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Alphaherpesvirinae. Chickens, turkeys, and quail serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: Marek's disease, which causes asymmetric paralysis of one or more limbs, neurological symptoms, and development of multiple lymphomas that manifest as solid tumors. Gallid herpesvirus 2 is the only one of these viruses known to be pathogenic and due to the antigenic similarity between the three viruses the other two have been used to vaccinate against Marek's disease. These viruses have double stranded DNA genomes with no RNA intermediate.
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.
Tectiviridae is a family of viruses with 10 species in five genera. Bacteria serve as natural hosts. Tectiviruses have no head-tail structure, but are capable of producing tail-like tubes of ~ 60×10 nm upon adsorption or after chloroform treatment. The name is derived from Latin tectus.
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.
Human bocavirus (HBoV) is the name given to all viruses in the genus Bocaparvovirus of virus family Parvoviridae that are known to infect humans. HBoV1 and HBoV3 are members of species Primate bocaparvovirus 1 whereas viruses HBoV2 and HBoV4 belong to species Primate bocaparvovirus 2. Some of these viruses cause human disease. HBoV1 is strongly implicated in causing some cases of lower respiratory tract infection, especially in young children, and several of the viruses have been linked to gastroenteritis, although the full clinical role of this emerging infectious disease remains to be elucidated.
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.
Haloarcula hispanica SH1 virus is a double-stranded DNA virus that infects the archaeon Haloarcula hispanica. This virus has a number of unique features that were unlike any other known virus when it was described. However similarities have since been found with the Thermus thermophilus virus P23-77 and the Thermus aquaticus virus IN93. These viruses may form a new taxon when in the next revision of the taxonomy by the ICTV.
Halorubrum pleomorphic virus 1 (HRPV-1) is a single stranded DNA virus that infects the species of the archaeal genus Halorubrum. It is unlike any other known virus infecting the archaea with a single stranded DNA genome and an external lipid envelope and is classified in the family Pleolipoviridae, genus Alphapleolipovirus, species Halorubrum virus HRPV1.
Tetraparvovirus are a genus of viruses in the family Parvoviridae. There are six recognized species: Chiropteran tetraparvovirus 1, Primate tetraparvovirus 1, Ungulate tetraparvovirus 1, Ungulate tetraparvovirus 2, Ungulate tetraparvovirus 3, and Ungulate tetraparvovirus 4.
Bidensovirus is a genus of single stranded DNA viruses that infect invertebrates. The species in this genus were originally classified in the family Parvoviridae but were moved to a new genus because of significant differences in the genomes.
Alphasphaerolipovirus is a genus of double stranded DNA viruses that infect haloarchaea. The genus contains four species.
Yingchengvirus is a genus of double stranded DNA viruses that infect haloarchaea. The genus was previously named Betasphaerolipovirus.
Hukuchivirus is a genus of double-stranded DNA viruses that infect thermophilic bacteria. The genus was previously named Gammasphaerolipovirus.
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.
Varidnaviria is a realm of viruses that includes all DNA viruses that encode major capsid proteins that contain a vertical jelly roll fold. The major capsid proteins (MCP) form into pseudohexameric subunits of the viral capsid, which stores the viral deoxyribonucleic acid (DNA), and are perpendicular, or vertical, to the surface of the capsid. Apart from this, viruses in the realm also share many other characteristics, such as minor capsid proteins (mCP) with the vertical jelly roll fold, an ATPase that packages viral DNA into the capsid, and a DNA polymerase that replicates the viral genome.
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.
