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Giant Viruses
A giant virus, sometimes referred to as a girus, is a very large virus, some of which are larger than typical bacteria. All known giant viruses belong to the phylum ''Nucleocytoviricota''. Description While the exact criteria as defined in the scientific literature vary, giant viruses are generally described as viruses having large, pseudo- icosahedral capsids (200 to 400 nanometers in diameter) that may be surrounded by a thick (approximately 100 nm) layer of filamentous protein fibers. The viruses have large, double-stranded DNA genomes (300 to >1000 kilobasepairs) that encode a large contingent of genes (of the order of 1000 genes). The best characterized giant viruses are the phylogenetically related mimivirus and megavirus, which belong to the family ''Mimiviridae'' (aka ''Megaviridae''), and are distinguished by their large capsid diameters. Giant viruses from the deep ocean, terrestrial sources, and human patients contain genes encoding cytochrome P450 (CYP; P450) e ... [...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] |
Esterification
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides are fatty acid esters of glycerol; they are important in biology, being one of the main classes of lipids and comprising the bulk of animal fats and vegetable oils. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. They perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties. '' Nomenclature Etymology The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pandoravirus
''Pandoravirus'' is a genus of giant virus, first discovered in 2013. It is the second largest in physical size of any known viral genus. Pandoraviruses have double stranded DNA genomes, with the largest genome size (2.5 million base pairs) of any known viral genus. Discovery The discovery of Pandoraviruses by a team of French scientists, led by husband and wife Jean-Michel Claverie and Chantal Abergel, was announced in a report in the journal ''Science'' in July 2013. Other scientists had previously observed the pandoravirus particles, but owing to their enormous size they were not expected to be viruses. Patrick Scheid, a parasitologist from the Central Institute of the Bundeswehr Medical Service in Koblenz, Germany, found one in 2008, in an amoeba living in the contact lens of a woman with keratitis. Its development within the amoebal host was documented extensively. Unlike in other cases with such giant viruses, the large particles within ''Acanthamoeba'' were not mistak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klosneuvirus
''Klosneuvirus'' (KNV, also KloV) is a new type of giant virus found by the analysis of low-complexity metagenomes from a wastewater treatment plant in Klosterneuburg, Austria. It has a 1.57-Mb genome coding unusually high number of genes typically found in cellular organisms, including aminoacyl transfer RNA synthetases with specificities for 19 different amino acids, over 10 translation factors and several tRNA-modifying enzymes. ''Klosneuvirus'', ''Indivirus'', ''Catovirus'' and ''Hokovirus'', are part of a group of giant viruses denoted as Klosneuviruses or '' Klosneuvirinae'', a proposed subfamily of the ''Mimiviridae''. Species in this clade include ''Bodo saltans virus'' infecting the kinetoplastid ''Bodo saltans''. Phylogenetic tree topology of ''Mimiviridae'' is still under discussion. As Klosneuviruses are related to ''Mimivirus'', it was proposed to put them all together into a subfamily ''Megavirinae''. Other authors (CNS 2018) like to put Klosneuviruses just t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Virus Finder
The Giant Virus Finder is a free bioinformatics software for finding giant viruses in metagenomes. Applications The Giant Virus Finder tool integrates and applies thGiant Virus Toplist the list of the largest virus genomes. With the tool, giant viruses were found in diverse habitats, like the Great Rann of Kutch or the Mojave Desert, the Prairie, or the Antarctic dry valleys The McMurdo Dry Valleys are a row of largely Antarctic oasis, snow-free valleys in Antarctica, located within Victoria Land west of McMurdo Sound. The Dry Valleys experience extremely low humidity and surrounding mountains prevent the flow of .... References {{reflist Metagenomics software Free bioinformatics software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tupanvirus
Tupanvirus is a genus of viruses first described in 2018. The genus is composed of two species of virus that are in the giant virus group. Researchers discovered the first isolate in 2012 from deep water sediment samples taken at 3000m depth off the coast of Brazil. The second isolate was collected from a soda lake in Southern Nhecolândia, Brazil in 2014. They are named after Tupã (Tupan), a Guaraní thunder god, and the places they were found. These are the first viruses reported to possess genes for amino-acyl tRNA synthetases for all 20 standard amino acids. Classification The genus Tupanvirus was first described in 2018 with the discovery of the two isolates of tupanviruses found in soda lake and deep oceanic sediments samples collected in Brazil. The genus is currently unassigned but hypothesized to be a member of the family ''Mimiviridae'', along with the other amoeba-infecting viruses. Members of the family ''Mimiviridae'' includes '' Acanthamoeba polyphaga mimivirus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimivirus
''Mimivirus'' is a genus of giant viruses, in the family ''Mimiviridae''. Amoeba serve as their natural hosts. This genus contains a single identified species named ''Acanthamoeba polyphaga mimivirus'' (APMV). It also refers to a group of phylogenetically related large viruses. In colloquial speech, APMV is more commonly referred to as just "mimivirus". Mimivirus, short for "mimicking microbe", is so called to reflect its large size and apparent Gram-staining properties. Mimivirus has a large and complex genome compared with most other viruses. Until 2013, when a larger virus ''Pandoravirus'' was described, it had the largest capsid diameter of all known viruses. History APMV was discovered accidentally in 1992 within the amoeba '' Acanthamoeba polyphaga'', after which it is named, during research into legionellosis by researchers from Marseille and Leeds. The virus was observed in a Gram stain and mistakenly thought to be a Gram-positive bacterium. As a consequence it was nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mamavirus
Mamavirus is a large and complex virus in the Group I family ''Mimiviridae''. The virus is exceptionally large, and larger than many bacteria. Mamavirus and other mimiviridae belong to nucleocytoplasmic large DNA virus (NCLDVs) family. Mamavirus can be compared to the similar complex virus mimivirus; mamavirus was so named because it is similar to but larger than mimivirus. Discovery Mamavirus was first reported in September 2008. Like mimivirus, mamavirus was isolated from an amoeba in a cooling tower. The mimiviridae were not discovered until recently because of their size; when filtered the mimiviridae stay with the bacteria which led scientists to believe they were also bacteria. Mimivirus was first isolated in 1992 when scientists were looking for the cause of a pneumonia outbreak in Bradford, UK. Due to its size it was named ''Bradfordcoccus'' and put in a freezer with scientists thinking it was a bacterium. A decade later, Jean-Michel Claverie and Didier Raoult discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megavirus Chilensis
Megavirus is a viral genus containing a single identified species named ''Megavirus chilensis'', phylogenetically related to Acanthamoeba polyphaga Mimivirus (APMV). In colloquial speech, Megavirus chilensis is more commonly referred to as just “Megavirus”. Until the discovery of pandoraviruses in 2013, it had the largest capsid diameter of all known viruses, as well as the largest and most complex genome among all known viruses. Discovery Megavirus was isolated from a water sample collected in April 2010 off the coast of Chile, near the marine station in Las Cruces, by Jean-Michel Claverie and Chantal Abergel from the Structural & Genomic Information laboratory (IGS, CNRS and Aix-Marseille University). Megavirus was isolated by co-cultivation with a variety of ''Acanthamoeba'' laboratory strains ('' A. polyphaga'', '' A. castellanii'', '' A. griffini'') following a protocol pioneered by Timothy Rowbotham for isolating intracellular parasitic bacteria. Megavirus infects a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bodo Saltans Virus
The Bodo saltans virus is a giant virus of the ''Mimiviridae'' family that infects the protozoa ''Bodo saltans''. It has a genome of 1.39 megabases A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DN ..., one of the largest known viral genomes. References Mimiviridae {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-domain System
The three-domain system is a biological classification introduced by Carl Woese, Otto Kandler, and Mark Wheelis in 1990 that divides cellular life forms into three domains, namely Archaea, Bacteria, and Eukaryota or Eukarya. The key difference from earlier classifications such as the two-empire system and the five-kingdom classification is the splitting of archaea from bacteria as completely different organism. It has been challenged by the two-domain system that divides organisms into Bacteria and Archaea only, as eukaryotes are considered as one group of archaea. Background Woese argued, on the basis of differences in 16S rRNA genes, that bacteria, archaea, and eukaryotes each arose separately from an ancestor with poorly developed genetic machinery, often called a progenote. To reflect these primary lines of descent, he treated each as a domain, divided into several different kingdom (biology), kingdoms. Originally his split of the prokaryotes was into ''Eubacteria'' (now ''B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome Size
Genome size is the total amount of DNA contained within one copy of a single complete genome. It is typically measured in terms of mass in picograms (trillionths (10−12) of a gram, abbreviated pg) or less frequently in daltons, or as the total number of nucleotide base pairs, usually in megabases (millions of base pairs, abbreviated Mb or Mbp). One picogram is equal to 978 megabases. In diploid organisms, genome size is often used interchangeably with the term C-value. An organism's complexity is not directly proportional to its genome size; total DNA content is widely variable between biological taxa. Some single-celled organisms have much more DNA than humans, for reasons that remain unclear (see non-coding DNA and C-value enigma). Origin of the term The term "genome size" is often erroneously attributed to a 1976 paper by Ralph Hinegardner, even in discussions dealing specifically with terminology in this area of research (e.g., Greilhuber 2005). Notably, Hinegardner u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
