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5,6-dihydrouracil
Dihydrouracil is an intermediate in the catabolism of uracil. It is the base present in the nucleoside dihydrouridine Dihydrouridine (abbreviated as D, DHU, or UH2) is a pyrimidine nucleoside which is the result of adding two hydrogen atoms to a uridine, making it a fully saturated pyrimidine ring with no remaining double bonds. D is found in tRNA and rRNA molec .... See also * Dihydrouracil dehydrogenase (NAD+) * Dihydrouracil oxidase * Dihydropyrimidinase References Nucleobases Ureas Pyrimidinediones {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrouracil Dehydrogenase (NAD+)
In enzymology, a dihydrouracil dehydrogenase (NAD+) () is an enzyme that catalyzes the chemical reaction :5,6-dihydrouracil + NAD+ \rightleftharpoons uracil + NADH + H+ Thus, the two substrates of this enzyme are 5,6-dihydrouracil and NAD+, whereas its 3 products are uracil, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 5,6-dihydrouracil:NAD+ oxidoreductase. Other names in common use include dehydrogenase, dihydrouracil, dihydropyrimidine dehydrogenase, dihydrothymine dehydrogenase, pyrimidine reductase, thymine reductase, uracil reductase, and dihydrouracil dehydrogenase (NAD+). This enzyme participates in 3 metabolic pathways: pyrimidine metabolism, beta-alanine metabolism, and pantothenate and coa biosynthesis Pantothenic acid, also called vitamin B5 is a water-soluble B vitamin and therefore an essential nutrie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrouracil Oxidase
In enzymology, a dihydrouracil oxidase () is an enzyme that catalyzes the chemical reaction :5,6-dihydrouracil + O2 \rightleftharpoons uracil + H2O2 Thus, the two substrates of this enzyme are 5,6-dihydrouracil and O2, whereas its two products are uracil and H2O2. This enzyme belongs to the family of oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...s, specifically those acting on the CH-CH group of donor with oxygen as acceptor. The systematic name of this enzyme class is 5,6-dihydrouracil:oxygen oxidoreductase. It employs one cofactor, FMN. References * EC 1.3.3 Flavoproteins Enzymes of unknown structure {{1.3-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydropyrimidinase
In enzymology, a dihydropyrimidinase () is an enzyme that catalyzes the chemical reaction :5,6-dihydrouracil + H2O \rightleftharpoons 3-ureidopropanoate Thus, the two substrates of this enzyme are 5,6-dihydrouracil and H2O, whereas its product is 3-ureidopropanoate. This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amides. The systematic name of this enzyme class is 5,6-dihydropyrimidine amidohydrolase. Other names in common use include hydantoinase, hydropyrimidine hydrase, hydantoin peptidase, pyrimidine hydrase, and D-hydantoinase. This enzyme participates in 3 metabolic pathways: pyrimidine metabolism, beta-alanine metabolism, and pantothenate and coa biosynthesis. Structural studies As of late 2007, 10 structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrouridine
Dihydrouridine (abbreviated as D, DHU, or UH2) is a pyrimidine nucleoside which is the result of adding two hydrogen atoms to a uridine, making it a fully saturated pyrimidine ring with no remaining double bonds. D is found in tRNA and rRNA molecules as a nucleoside; the corresponding nucleobase is 5,6-dihydrouracil. Because it is non-planar, D disturbs the stacking interactions in helices and destabilizes the RNA structure. D also stabilizes the C2’-''endo'' sugar conformation, which is more flexible than the C3’-''endo'' conformation; this effect is propagated to the 5’-neighboring residue. Thus, while pseudouridine and 2’-O-methylations stabilize the local RNA structure, D does the opposite. The tRNAs of organisms that grow at low temperatures (psychrophile Psychrophiles or cryophiles (adj. ''psychrophilic'' or ''cryophilic'') are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from to . They have an optimal growt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uracil
Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine (T). Uracil is a demethylated form of thymine. Uracil is a common and naturally occurring pyrimidine derivative. The name "uracil" was coined in 1885 by the German chemist Robert Behrend, who was attempting to synthesize derivatives of uric acid. Originally discovered in 1900 by Alberto Ascoli, it was isolated by hydrolysis of yeast nuclein; it was also found in bovine thymus and spleen, herring sperm, and wheat germ. It is a planar, unsaturated compound that has the ability to absorb light. Based on 12C/13C isotopic ratios of organic compounds found in the Murchison meteorite, it is believed that uracil, xanthine, and related molecules can also be formed extraterrestrially. Data from the Cassini mission, orbiting in the Saturn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building-blocks of DNA and RNA. List of nucleosides and corresponding nucleobases The reason for 2 symbols, shorter and longer, is that the shorter ones are better for contexts where explicit disambiguation is superfluous (because context disambiguates) and the longer ones are for contexts where explicit disambiguation is judged to be needed or wise. For example, when discussing long nucleobase sequences in genomes, the CATG symbol system is much preferable to the Cyt-Ade-Thy-Gua symbol system (see '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleobases
Nucleobases, also known as ''nitrogenous bases'' or often simply ''bases'', are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic building blocks of nucleic acids. The ability of nucleobases to form base pairs and to stack one upon another leads directly to long-chain helical structures such as ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Five nucleobases—adenine (A), cytosine (C), guanine (G), thymine (T), and uracil (U)—are called ''primary'' or ''canonical''. They function as the fundamental units of the genetic code, with the bases A, G, C, and T being found in DNA while A, G, C, and U are found in RNA. Thymine and uracil are distinguished by merely the presence or absence of a methyl group on the fifth carbon (C5) of these heterocyclic six-membered rings. In addition, some viruses have aminoadenine (Z) instead of adenine. It differs in having an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ureas
220 px, B vitamin, is a urea. In chemistry, ureas are a class of organic compounds with the formula (R2N)2CO where R = H, alkyl, aryl, etc. Thus, in addition to describing the specific chemical compound urea ((H2N)2CO), urea is the name of a functional group that is found in many compounds and materials of both practical and theoretical interest. Generally ureas are colorless crystalline solids, which, owing to the presence of fewer hydrogen bonds, exhibit melting points lower than that of urea itself. Synthesis Ureas can be prepared many methods, but rarely by direct carbonation, which is the route to urea itself. Instead, methods can be classified according those that assemble the urea functionality and those that start with preformed urea. Assembly of N-substituted urea functionality Phosgenation entails the reaction of amines with phosgene, proceeding via the isocyanate (or carbamoyl chloride) as an intermediate: :COCl2 + R2NH → R2NC(O)Cl + HCl :COCl2 + RNH2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
