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HUH-tag
HUH endonucleases (HUH-tags) are sequence-specific single-stranded DNA (ssDNA) binding proteins originating from numerous species of bacteria and viruses. Viral HUH endonucleases are involved in initiating rolling circle replication while ones of bacterial origin initiate bacterial conjugation. In biotechnology, they can be used to create protein-DNA linkages, akin to other methods such as SNAP-tag. In doing so, they create a 5' covalent bond between the ssDNA and the protein. HUH endonucleases can be fused with other proteins or used as protein tags. The name HUH stands for "histidine-hydrophobic-histidine," referring to the three amino acids at the active site of the endonuclease. Some DNA viruses code for an HUH endonuclease which initiates rolling circle replication of the viral genome, and this process defines the realm ''Monodnaviria''. Types of HUH endonucleases HUH endonucleases are broadly split into two categories of enzymes: replication initiator proteins (Rep) or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Tag
Protein tags are peptide sequences genetically grafted onto a recombinant protein. Tags are attached to proteins for various purposes. They can be added to either end of the target protein, so they are either C-terminus or N-terminus specific or are both C-terminus and N-terminus specific. Some tags are also inserted at sites within the protein of interest; they are known as internal tags. Affinity tags are appended to proteins so that they can be purified from their crude biological source using an affinity technique. Affinity tags include chitin binding protein (CBP), maltose binding protein (MBP), Strep-tag and glutathione-S-transferase (GST). The Polyhistidine-tag, poly(His) tag is a widely used protein tag, which binds to matrices bearing immobilized metal ions. Solubilization tags are used, especially for recombinant proteins expressed in species such as ''E. coli'', to assist in the proper folding in proteins and keep them from aggregating in inclusion bodies. These tags ... [...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 Conserved sequence, 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-tag, 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 en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monodnaviria
''Monodnaviria'' is a Realm (virology), realm of viruses that includes all DNA virus#Group II: ssDNA viruses, single-stranded DNA viruses that Genetic code, encode an HUH-tag, endonuclease of the HUH superfamily that initiates rolling circle replication (RCR) of the circular viral genome. Viruses descended from such viruses are also included in the realm, including certain linear single-stranded DNA (ssDNA) viruses and circular double-stranded DNA (dsDNA) viruses. These atypical members typically replicate through means other than rolling circle replication. ''Monodnaviria'' was established in 2019 and contains four kingdoms: ''Loebvirae'', ''Sangervirae'', ''Trapavirae'', and ''Shotokuvirae''. Viruses in the first three kingdoms infect prokaryotes, and viruses in ''Shotokuvirae'' infect eukaryotes and include the atypical members of the realm. Viruses in ''Monodnaviria'' appear to have come into existence independently multiple times from circular bacterial and archaeal plasmids t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HUH Reaction
Huh or HUH may refer to: Linguistics * Huh? (paralanguage), a universal utterance requesting clarification Arts and entertainment * ''huH'' (magazine), a 1994–1996 American music magazine * ''Huh?'', a 1991 animated short film by Mike Judge * "HuH", a 2010 song by 4Minute from '' Hit Your Heart'' * '' Sweet Heart Sweet Light'' (working title: ''Huh?''), a 2012 album by Spiritualized Acronyms and codes * HUH-tag (histidine-hydrophobic-histidine), a DNA binding protein * Harvard University Herbaria, Cambridge, Massachusetts, U.S. * Howard University Hospital, Washington, D.C., U.S. * Huahine – Fare Airport (IATA code), French Polynesia * Huilliche language (ISO 639-3 code), an Araucanian language in Chile * Hung Hom station Hung Hom () is a passenger railway List of MTR stations, station in Hung Hom, Kowloon, Hong Kong. It is an interchange station between the and the domestic services of the MTR network. This station serves the southern terminus of the East Ra ... (s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endonuclease
In molecular biology, endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain (namely DNA or RNA). Some, such as deoxyribonuclease I, cut DNA relatively nonspecifically (with regard to sequence), while many, typically called '' restriction endonucleases'' or ''restriction enzymes'', cleave only at very specific nucleotide sequences. Endonucleases differ from exonucleases, which cleave the ends of recognition sequences instead of the middle (''endo'') portion. Some enzymes known as "exo-endonucleases", however, are not limited to either nuclease function, displaying qualities that are both endo- and exo-like. Evidence suggests that endonuclease activity experiences a lag compared to exonuclease activity. Restriction enzymes are endonucleases from eubacteria and archaea that recognize a specific DNA sequence. The nucleotide sequence recognized for cleavage by a restriction enzyme is called the ''restriction site''. Typically, a restriction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porcine Circovirus
Porcine circovirus (PCV) is a group of four single-stranded DNA viruses that are non-enveloped with an unsegmented circular genome. They are members of the genus ''Circovirus'' that can infect pigs. The viral capsid is icosahedral and approximately 17 nm in diameter. PCVs are the smallest viruses replicating autonomously in eukaryotic cells. They replicate in the nucleus of infected cells, using the host polymerase for genome amplification. PCV-2 causes Porcine circovirus associated disease or postweaning multisystemic wasting syndrome (PMWS). An effective vaccination is now available. Fort Dodge Animal Health (Wyeth) launched the first USDA approved vaccine in 2006, containing an inactivated virus (ATCvet code: ). Classification Three strains of PCV are known as of 2018: * PCV-1 (first identified in 1974) readily infects, but is not known to cause disease in swine. * PCV-2 (first isolated in 1997) causes PMWS, which over time results in significant depletion of lymph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adeno-associated Virus
Adeno-associated viruses (AAV) are small viruses that infect humans and some other primate species. They belong to the genus '' Dependoparvovirus'', which in turn belongs to the family ''Parvoviridae''. They are small (approximately 26 nm in diameter) replication-defective, nonenveloped viruses and have linear single-stranded DNA (ssDNA) genome of approximately 4.8 kilobases (kb). Several features make AAV an attractive candidate for creating viral vectors for gene therapy, and for the creation of isogenic human disease models. Gene therapy vectors using AAV can infect both dividing and quiescent cells and persist in an extrachromosomal state without integrating into the genome of the host cell. In the native virus, however, integration of virally carried genes into the host genome does occur. Integration can be important for certain applications, but can also have unwanted consequences. Recent human clinical trials using AAV for gene therapy in the retina have shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The virus genomic component inside the capsid, along with occasionally present virus core protein, is called the virus core. The capsid and core together are referred to as a nucleocapsid (cf. also virion). Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WDV Rep Cleavage Mechanism
The written-down value (abbreviated as WDV) is the depreciated value of an asset (movable or immovable) for purposes of tax A tax is a mandatory financial charge or levy imposed on an individual or legal entity by a governmental organization to support government spending and public expenditures collectively or to regulate and reduce negative externalities. Tax co ...ation. WDV is a method of depreciation in which a fixed rate of depreciation is charged on the book value of the asset, over its useful life External links Definition at The Free Dictionary Fixed asset {{Econ-term-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mg²⁺
Magnesium is a chemical element; it has symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table), it occurs naturally only in combination with other elements and almost always has an oxidation state of +2. It reacts readily with air to form a thin passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight alloys that contain aluminium. In the cosmos, magnesium is produced in large, aging stars by the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the interstellar medium where it may r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Magnetic Resonance
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000 MHz). NMR results from specific magnetic properties of certain atomic nuclei. High-resolution nuclear magnetic resonance spectroscopy is widely used to determine the structure of organic molecules in solution and study molecular physics and crystals as well as non-crysta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring the angles and intensities of the X-ray diffraction, a crystallography, crystallographer can produce a three-dimensional picture of the density of electrons within the crystal and the positions of the atoms, as well as their chemical bonds, crystallographic disorder, and other information. X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences between various materials, especially minerals and alloys. The method has also revealed the structure and function of many biological molecules, including vitamins, drugs, proteins and nucleic acids such as DNA. X-ray crystall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
