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Adnaviria
''Adnaviria'' is a realm of viruses that includes archaeal viruses that have a filamentous virion (i.e. body) 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. ''Adnaviria'' was established in 2020 after cryogenic electron microscopy showed that the viruses in the realm were related due to a shared MCP, A-DNA, and general virion structure. Viruses in ''Adnaviria'' infect hyperthermophilic archaea, i.e. archaea that inhabit very high temperature environments such as hot sprin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeal Viruses
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). Much of the diversity observed in archaeal viruses is their morphology. Their complete bodies, called virions, come in many different forms, including being shaped like spindles or lemons, rods, bottles, droplets, and coils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeal Virus
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). Much of the diversity observed in archaeal viruses is their morphology. Their complete bodies, called virions, come in many different forms, including being shaped like spindles or lemons, rods, bottles, droplets, and coils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realm (virology)
In virology, realm is the highest taxonomic rank established for viruses by the International Committee on Taxonomy of Viruses (ICTV), which oversees virus taxonomy. Six virus realms are recognized and united by specific highly conserved traits: * ''Adnaviria'', which contains archaeal filamentous viruses with A-form double-stranded (ds) DNA genomes encoding a unique alpha-helical major capsid protein; * ''Duplodnaviria'', which contains all dsDNA viruses that encode the HK97-fold major capsid protein; * ''Monodnaviria'', which contains all single-stranded DNA (ssDNA) viruses that encode a HUH superfamily endonuclease and their descendants; * '' Riboviria'', which contains all RNA viruses that encode RNA-dependent RNA polymerase and all viruses that encode reverse transcriptase; * ''Ribozyviria'', which contains hepatitis delta-like viruses with circular, negative-sense ssRNA genomes; * and ''Varidnaviria'', which contains all dsDNA viruses that encode a vertical jelly rol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Higher Virus Taxa
:''This is a list of biological virus upper-level taxa. See also Comparison of computer viruses'' This is an alphabetical list of biological virus higher taxa. It includes those taxa above Family (biology), family, ranging from Realm (virology), realm to suborder, that are included in the International Committee on Taxonomy of Viruses, ICTV's 2020 taxonomy release. For a list of individual species, see List of virus species. For a list of virus genera, see List of genera of viruses. For a list of family-level viral taxa, see List of virus families and subfamilies. Realms *''Adnaviria'' *''Duplodnaviria'' *''Monodnaviria'' *''Riboviria'' *''Ribozyviria'' *''Varidnaviria'' Kingdoms *''Bamfordvirae'' *''Heunggongvirae'' *''Helvetiavirae'' *''Loebvirae'' *''Orthornavirae'' *''Pararnavirae'' *''Sangervirae'' *''Shotokuvirae'' *''Trapavirae'' *''Zilligvirae'' Phyla and subphyla Phyla *''Artverviricota'' *''Cossaviricota'' *''Cressdnaviricota'' *''Dividoviricota'' *''Duplornaviric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipothrixviridae
''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 Janekovic, D., Wunderl S, Holz I, Zillig W, Gierl A, Neumann H (1983) TTV1, TTV2 and TTV3, a family of viruses of the extremely thermophilic anaerobic, sulphur reducing, archaeabacterium Thermoproteus tenax. Mol. Gen. Genet. 19239–19245 Taxonomy The following genera and species are assigned to the family: * ''Alphalipothrixvirus'' ** '' Alphalipothrixvirus SBFV2'' ** '' Alphalipothrixvirus SFV1'' * '' Betalipothrixvirus'' ** '' Acidianus filamentous virus 3'' ** '' Acidianus filamentous virus 6'' ** '' Acidianus filamentous virus 7'' ** '' Acidianus filamentous virus 8'' ** '' Acidianus filamentous virus 9'' ** ''Sulfolobus islandicus filamentous virus'' * ''Deltalipothrixvirus'' ** ''Acidianus filamentous virus 2'' ** ''Deltalipothrixvirus SBFV3'' The family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoproteales
In taxonomy, the Thermoproteales are an order of the Thermoprotei The Thermoprotei is a class of the Thermoproteota. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information The National Cente .... They are the only organisms known to lack the SSB proteins, instead possessing the protein ThermoDBP that has displaced them. The rRNA genes of these organisms contain multiple introns, which can be homing endonuclease encoding genes, and their presence can impact the binding of "universal" 16S rRNA primers often used in environmental sequencing surveys. References Further reading Scientific journals * * * * * * * * Scientific books * Scientific databases External links Archaea taxonomic orders Thermoproteota {{Crenarchaeota-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primavirales
''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. Taxonomy The following genera and species are assigned to the family: * '' Alphatristromavirus'' ** '' Alphatristromavirus PFV1'' ** '' Alphatristromavirus PFV2'' * '' Betatristromavirus'' ** ''Betatristromavirus TTV1'' Structure Viruses in the genus ''Tristromaviridae'' are enveloped, with rod-shaped geometries. The diameter is around 38 nm, with a length of 410 nm. Genomes are linear, around 15.9kb in length. The TTV1 virion contains four virus-encoded proteins, TP1-4. The proteins do not display any sequence similarity to structural proteins of viruses from other families, including lipothrixviruses. Nucleocapsid protein TP1 has apparently evolved from a Cas4 endonuclease, a conserved component of the adaptive CRISPR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfolobales
In taxonomy, the Sulfolobales are an order of the Thermoprotei. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI) DNA transfer Exposure of ''Sulfolobus solfataricus'' to the DNA damaging agents UV-irradiation, bleomycin or Mitomycins, mitomycin C induces cellular aggregation. Other physical stressors, such as pH or temperature shift, do not induce aggregation, suggesting that induction of aggregation is caused specifically by DNA damage. Ajon et al. showed that UV-induced cellular aggregation mediates chromosomal marker exchange with high frequency. Recombination rates exceeded those of uninduced cultures by up to three orders of magnitude. Frols et al. and Ajon et al. hypothesized that the UV-inducible DNA transfer process and subsequent homologous recombinational repair represents an important mechanism to maintain chromosome integrity. This r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligamenvirales
''Ligamenvirales'' is an order of linear viruses that infect archaea of the phylum Thermoproteota (formerly Crenarchaeota) and have double-stranded DNA genomes. The order was proposed by David Prangishvili and Mart Krupovic in 2012 and subsequently created by the International Committee on Taxonomy of Viruses (ICTV). The name is derived from the Latin {{lang, la, ligamen, meaning ''string'' or ''thread''.{{cn, date=November 2022 Taxonomy There are three families in this order – ''Lipothrixviridae'', ''Rudiviridae'' and '' Ungulaviridae''.{{cn, date=November 2022 The virons are filamentous with a helical nucleocapsid. At either end are attached either fibers or more complex structures involved in host adhesion.{{cn, date=November 2022 The major coat proteins of both lipothrixviruses and rudiviruses have an unusual four-helix bundle topology.Goulet A, Blangy S, Redder P, Prangishvili D, Felisberto-Rodrigues C, Forterre P, Campanacci V, Cambillau C (2009) Acidianus filamentous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavaviridae
''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). The name is derived from the Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ... word ''clava'' meaning stick. Virology The virons are bacilliform in shape and 143 nanometers (nm) in length and 15.8 nm in diameter. One end is pointed and the other is rounded. The structure of the APBV1 virion has been solved by cryo-electron microscopy to near-atomic resolution, revealing how the helical particle is built from an alpha-helical major capsid protein with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRISPR
CRISPR () (an acronym for clustered regularly interspaced short palindromic repeats) is a family of DNA sequences found in the genomes of prokaryotic organisms such as bacteria and archaea. These sequences are derived from DNA fragments of bacteriophages that had previously infected the prokaryote. They are used to detect and destroy DNA from similar bacteriophages during subsequent infections. Hence these sequences play a key role in the antiviral (i.e. anti-phage) defense system of prokaryotes and provide a form of acquired immunity. CRISPR is found in approximately 50% of sequenced bacterial genomes and nearly 90% of sequenced archaea. Cas9 (or "CRISPR-associated protein 9") is an enzyme that uses CRISPR sequences as a guide to recognize and cleave specific strands of DNA that are complementary to the CRISPR sequence. Cas9 enzymes together with CRISPR sequences form the basis of a technology known as CRISPR-Cas9 that can be used to edit genes within organisms. This editing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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