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Erythrose-4-phosphate
Erythrose 4-phosphate is a phosphate of the simple sugar erythrose. It is an intermediate in the pentose phosphate pathway and the Calvin cycle. In addition, it serves as a precursor in the biosynthesis of the aromatic amino acids tyrosine, phenylalanine, and tryptophan. It is used in the first step of the shikimate pathway. At this stage, phosphoenolpyruvate and erythrose-4-phosphate react to form 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase. : It also used in 3-hydroxy-1-aminoacetone phosphate biosynthesis, which is a precursor of vitamin B6 in DXP-dependent pathway. Erythrose-4-phosphate dehydrogenase In enzymology, an erythrose-4-phosphate dehydrogenase () is an enzyme that catalyzes the chemical reaction :D-erythrose 4-phosphate + NAD+ + H2O \rightleftharpoons 4-phosphoerythronate + NADH + 2 H+ The 3 substrates of this enzyme are D-eryt ... is used to produce erythronate-4-phosphate. References {{bioc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-deoxy-D-arabinoheptulosonate-7-phosphate
3-Deoxy--''arabino''-heptulosonic acid 7-phosphate (DAHP) is a 7-carbon ulonic acid. This compound is found in the shikimic acid biosynthesis pathway and is an intermediate in the production of aromatic amino acids. Phosphoenolpyruvate and erythrose-4-phosphate react to form 3-deoxy--''arabino''-heptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase. : DAHP is then transformed to 3-dehydroquinate (DHQ), in a reaction catalyzed by DHQ synthase. Although this reaction requires nicotinamide adenine dinucleotide (NAD) as a cofactor, the enzymic mechanism regenerates it, resulting in the net use of no NAD. : The mechanism of ring closure is complex, but involves an aldol condensation at C-2 and C-7. Metabolic engineering has improved production of DAHP by ''Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythrose-4-phosphate Dehydrogenase
In enzymology, an erythrose-4-phosphate dehydrogenase () is an enzyme that catalyzes the chemical reaction :D-erythrose 4-phosphate + NAD+ + H2O \rightleftharpoons 4-phosphoerythronate + NADH + 2 H+ The 3 substrates of this enzyme are D-erythrose 4-phosphate, NAD+, and H2O, whereas its 3 products are 4-phosphoerythronat, NADH, and H+. xplainpolicedepartment This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ... of this enzyme class is D-erythrose 4-phosphate:NAD+ oxidoreductase. Other names in common use include erythrose 4-phosphate dehydrogenase, E4PDH, GapB, Epd dehydrogenase, and E4P dehydrogenase. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DAHP Synthase
3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase () is the first enzyme in a series of metabolic reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway. Enzyme inhibition is the primary method of regulating the amount of carbon entering the pathway. Forms of this enzyme differ between organisms, but can be considered DAHP synthase based upon the reaction that is catalyzed by this enzyme. In enzymology, a DAHP synthase () is an enzyme that catalyzes the chemical reaction :phosphoenolpyruvate + D-erythrose 4-phosphate + H2O \rightleftharpoons 3-deoxy-D-arabino-hept-2-ulosonate 7-phosphate + phosphate The three substrates of this enzyme are phosphoenolpyruvate, D-erythrose 4-phosphate, and H2O, whereas its two products are 3-deoxy-D-arabino-hept-2-ulosonate 7-phosphate and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridoxal Phosphate
Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates. Role as a coenzyme PLP acts as a coenzyme in all transamination reactions, and in certain decarboxylation, deamination, and racemization reactions of amino acids. The aldehyde group of PLP forms a Schiff-base linkage (internal aldimine) with the ε-amino group of a specific lysine group of the aminotransferase enzyme. The α-amino group of the amino acid substrate displaces the ε-amino group of the active-site lysine residue in a process known as transaldimination. The resulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin B6
Vitamin B6 is one of the B vitamins, and thus an essential nutrient. The term refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosphate, serves as a coenzyme in more than 140 enzyme reactions in amino acid, glucose, and lipid metabolism. Plants synthesize pyridoxine as a means of protection from the ultraviolet-B radiation of sunlight and to participate in synthesis of chlorophyll. Animals cannot synthesize any of the various forms of the vitamin, and hence must obtain it via diet, either of plants, or of other animals. There is some absorption of the vitamin produced by intestinal bacteria, but this is not sufficient to meet needs. For adult humans, recommendations from various countries' food regulatory agencies are in the range of 1.0 to 2.0 milligrams (mg) per day. These same agencies also recognize ill effects from intakes that are too high, and so set safe upper l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DAHP Synthase Reaction , an intermediate in the biosynthesis of shikimic acid
{{disambiguation ...
DAHP may refer to: * Washington State Department of Archaeology and Historic Preservation, an independent government agency in Washington state * 3-deoxy-D-arabinoheptulosonate-7-phosphate 3-Deoxy--''arabino''-heptulosonic acid 7-phosphate (DAHP) is a 7-carbon ulonic acid. This compound is found in the shikimic acid biosynthesis pathway and is an intermediate in the production of aromatic amino acids. Phosphoenolpyruvate and er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one or two protons gives the dihydrogen phosphate ion and the hydrogen phosphate ion ion, respectively. These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate In organic chemistry, phosphate or orthophosphate is an organophosphate, an ester of orthophosphoric acid of the form where one or more hydrogen atoms are replaced by organic groups. An example is trimethyl phosphate, . The term also refers to the triv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erythrose
Erythrose is a tetrose saccharide with the chemical formula C4H8O4. It has one aldehyde group, and is thus part of the aldose family. The natural isomer is D-erythrose; it is a diastereomer of D -threose. Erythrose was first isolated in 1849 from rhubarb by the French pharmacist Louis Feux Joseph Garot (1798-1869), and was named as such because of its red hue in the presence of alkali metals (ἐρυθρός, "red"). Erythrose 4-phosphate is an intermediate in the pentose phosphate pathway and the Calvin cycle. Oxidative bacteria can be made to use erythrose as its sole energy source. See also * Erythritol Erythritol is an organic compound, a four-carbon sugar alcohol (or polyol) with no optical activity, used as a food additive and sugar substitute. It is naturally occurring. It can be made from corn using enzymes and fermentation. Its formula i ... References {{Carbohydrates Aldotetroses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoenolpyruvate
Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the ester derived from the enol of pyruvate and phosphate. It exists as an anion. PEP is an important intermediate in biochemistry. It has the highest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved in glycolysis and gluconeogenesis. In plants, it is also involved in the biosynthesis of various aromatic compounds, and in carbon fixation; in bacteria, it is also used as the source of energy for the phosphotransferase system. In glycolysis PEP is formed by the action of the enzyme enolase on 2-phosphoglyceric acid. Metabolism of PEP to pyruvic acid by pyruvate kinase (PK) generates adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells. In gluconeogenesis PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecule. This reaction is catalyzed by the enzyme pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shikimate Pathway
The shikimate pathway (shikimic acid pathway) is a seven-step metabolic pathway used by bacteria, archaea, fungi, algae, some protozoans, and plants for the biosynthesis of folates and aromatic amino acids (tryptophan, phenylalanine, and tyrosine). This pathway is not found in animal cells. The seven enzymes involved in the shikimate pathway are DAHP synthase, 3-dehydroquinate synthase, 3-dehydroquinate dehydratase, shikimate dehydrogenase, shikimate kinase, EPSP synthase, and chorismate synthase. The pathway starts with two substrates, phosphoenol pyruvate and erythrose-4-phosphate, and ends with chorismate, a substrate for the three aromatic amino acids. The fifth enzyme involved is the shikimate kinase, an enzyme that catalyzes the ATP-dependent phosphorylation of shikimate to form shikimate 3-phosphate (shown in the figure below). Shikimate 3-phosphate is then coupled with phosphoenol pyruvate to give 5-enolpyruvylshikimate-3-phosphate via the enzyme 5-enolpyruvylshikimate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
