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Nuclear-inclusion-a Endopeptidase
Nuclear-inclusion-a endopeptidase (, ''potyvirus NIa protease'') is a protease enzyme found in potyviruses. This enzyme catalyses the following chemical reaction: : Hydrolyses glutaminyl bonds, and activity is further restricted by preferences for the amino acids in P6 - P1' that vary with the species of potyvirus. : e.g. Glu-Xaa-Xaa-Tyr-Xaa-Gln \ (Ser or Gly) for the enzyme from tobacco etch virus. The enzyme is used encoded in vectors for the artificial expression of recombinant fusion proteins (see TEV protease TEV protease (, ''Tobacco Etch Virus nuclear-inclusion-a endopeptidase'') is a highly sequence-specific cysteine protease from Tobacco Etch Virus (TEV). It is a member of the PA clan of chymotrypsin-like proteases. Due to its high sequence sp ...). References External links * {{Portal bar, Biology, border=no EC 3.4.22 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks Covalent bond, bonds. Proteases are involved in numerous biological pathways, including Digestion#Protein digestion, digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently convergent evolution, evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Classification Based on catalytic residue Proteases can be classified into seven broad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyvirus
''Potyvirus'' is a genus of positive-strand RNA viruses (named after its type species, potato virus Y, Potato virus Y (''Potyvirus yituberosi,'' PVY)'')'' in the family ''Potyviridae''. Plants serve as natural hosts. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, Horticulture industry, horticultural, and Ornamental plant, ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily ''Aphidinae'' (genera ''Macrosiphum'' and ''Myzus''). The genus contains 190 species and potyviruses account for about thirty percent of all currently known plant viruses. Structure The virion is Viral envelope, non-enveloped with a flexuous and filamentous Capsid, nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains around 2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4-3.5 nm. Genome The genome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolyses
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and water molecule to split into two parts. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Etch Virus
Tobacco etch virus (TEV) is a plant virus in the genus ''Potyvirus'' and family ''Potyviridae''. Like other members of the genus ''Potyvirus'', TEV has a monopartite positive-sense, single-stranded RNA genome surrounded by a capsid made from a single viral encoded protein. The virus is a filamentous particle that measures about 730 nm in length. It is transmissible in a non-persistent manner by more than 10 species of aphids including ''Myzus persicae''. It also is easily transmitted by mechanical means but is not known to be transmitted by seeds. Host range This virus infects many species of Solanaceae. Agriculturally important crops that it infects include several species of ''Capsicum'' (i.e. '' C. annuum'', '' C. frutescens''), tomato (''Lycopersicon esculentum''), and tobacco (''Nicotiana spp.''). It also infects many perennial weed species that can act as virus reservoirs for susceptible agricultural crops. These weed species include ''Solanum nigrum'' (nightshade) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinant Fusion Protein
Fusion proteins or chimeric (kī-ˈmir-ik) proteins (literally, made of parts from different sources) are proteins created through the joining of two or more genes that originally coded for separate proteins. Translation of this ''fusion gene'' results in a single or multiple polypeptides with functional properties derived from each of the original proteins. ''Recombinant fusion proteins'' are created artificially by recombinant DNA technology for use in biological research or therapeutics. ''Chimera (genetics), Chimeric'' or ''chimera'' usually designate hybrid proteins made of polypeptides having different functions or physico-chemical patterns. ''Chimeric mutant proteins'' occur naturally when a complex mutation, such as a chromosomal translocation, tandem duplication, or retrotransposition creates a novel coding sequence containing parts of the coding sequences from two different genes. Naturally occurring fusion proteins are commonly found in cancer cells, where they may funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TEV Protease
TEV protease (, ''Tobacco Etch Virus nuclear-inclusion-a endopeptidase'') is a highly sequence-specific cysteine protease from Tobacco Etch Virus (TEV). It is a member of the PA clan of chymotrypsin-like proteases. Due to its high sequence specificity, TEV protease is frequently used for the controlled cleavage of fusion proteins ''in vitro'' and ''in vivo''. The consensus sequence recognized by TEV protease is Glu-Asn-Leu-Tyr-Phe-Gln-, -Ser, where ", " denotes cleaved peptide bond. Origin The tobacco etch virus encodes its entire genome as a single massive polyprotein (350 kDa). This is cleaved into functional units by the three proteases: P1 protease (1 cleavage site), helper-component protease (1 cleavage site) and TEV protease (7 cleavage sites).UniProt: TEV polyprotein: The native TEV protease also contains an internal self-cleavage site. This site is slowly cleaved to inactivate the enzyme (the physiological reason for this is unknown). Structure and function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
