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Phosphoribosylglycinamide Formyltransferase
Phosphoribosylglycinamide formyltransferase (, ''2-amino-N-ribosylacetamide 5'-phosphate transformylase'', ''GAR formyltransferase'', ''GAR transformylase'', ''glycinamide ribonucleotide transformylase'', ''GAR TFase'', ''5,10-methenyltetrahydrofolate:2-amino-N-ribosylacetamide ribonucleotide transformylase'') is an enzyme with systematic name ''10-formyltetrahydrofolate:5'-phosphoribosylglycinamide N-formyltransferase''. This enzyme catalyses the following chemical reaction : 10-formyltetrahydrofolate + N1-(5-phospho-D-ribosyl)glycinamide \rightleftharpoons tetrahydrofolate + N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide This THF dependent enzyme catalyzes a nucleophilic acyl substitution of the formyl group from 10-formyltetrahydrofolate (fTHF) to N1-(5-phospho-D-ribosyl)glycinamide (GAR) to form N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide (fGAR) as shown above. This reaction plays an important role in the formation of purine through the ''de novo'' purine biosynthesis pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Adenine Dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD and NADH (H for hydrogen), respectively. In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another. The cofactor is, therefore, found in two forms in cells: NAD is an oxidizing agent – it accepts electrons from other molecules and becomes reduced. This reaction, also with H+, forms NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. However, it is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAR Transformylase Mechanism Suggested By Qiao Et Al
Gars are members of the family Lepisosteidae, which are the only surviving members of the Ginglymodi, an ancient holosteian group of ray-finned fish, which first appeared during the Triassic, over 240 million years ago. Gars comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba in the Caribbean, though extinct members of the family were more widespread. Gars have elongated bodies that are heavily armored with ganoid scales, and fronted by similarly elongated jaws filled with long, sharp teeth. Gars are sometimes referred to as "garpike", but are not closely related to pike, which are in the fish family Esocidae. All of the gars are relatively large fish, but the alligator gar (''Atractosteus spatula'') is the largest; the alligator gar often grows to a length over and a weight over , and specimens of up to in length have been reported. Unusually, their vascularised swim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford Synchrotron Radiation Laboratory
The Stanford Synchrotron Radiation Lightsource (formerly Stanford Synchrotron Radiation Laboratory), a division of SLAC National Accelerator Laboratory, is operated by Stanford University for the Department of Energy. SSRL is a National User Facility which provides synchrotron radiation, a name given to electromagnetic radiation in the x-ray, ultraviolet, visible and infrared realms produced by electrons circulating in a storage ring (Stanford Positron Electron Asymmetric Ring - SPEAR) at nearly the speed of light. The extremely bright light that is produced can be used to investigate various forms of matter ranging from objects of atomic and molecular size to man-made materials with unusual properties. The obtained information and knowledge is of great value to society, with impact in areas such as the environment, future technologies, health, biology, basic research, and education. SSRL provides experimental facilities to some 2,000 academic and industrial scientists working in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIR Synthetase (FGAM Cyclase)
Phosphoribosylformylglycinamidine cyclo-ligase (AIR synthetase) is the fifth enzyme () in the ''de novo'' synthesis of purine nucleotides. It catalyzes the reaction to form 5-aminoimidazole ribotide (AIR) from formylglycinamidine-ribonucleotide FGAM. This reaction closes the ring and produces a 5-membered imidazole ring of the purine nucleus (AIR): ATP + 2-(formamido)-N1-(5-phospho-β-D-ribosyl)acetamidine \rightleftharpoons ADP + 5-amino-1-(5-phospho-β-D-ribosyl)imidazole + phosphate + AIR synthetase catalyzes the transfer of the oxygen of the formyl group to phosphate. It is a sequential mechanism in which ATP binds first to the enzyme and ADP is released last. This enzyme hydrolyzes ATP to activate the oxygen of the amide in order to carry out a nucleophilic attack by nitrogen. In humans and many other animals, this enzyme is contained within the trifunctional purine biosynthetic protein adenosine-3 polypeptide. Nomenclature The systematic name of this enzyme class is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoribosylamine—glycine Ligase
''Phosphoribosylamine—glycine ligase'', also known as glycinamide ribonucleotide synthetase (GARS), () is an enzyme that catalyzes the chemical reaction :ATP + 5-phospho-D-ribosylamine + glycine \rightleftharpoons ADP + phosphate + which is the second step in purine biosynthesis. The 3 substrates of this enzyme are ATP, 5-phospho-D-ribosylamine, and glycine, whereas its 3 products are ADP, phosphate, and . This enzyme belongs to the family of ligases, specifically those forming generic carbon-nitrogen bonds. In bacteria, GARS is a monofunctional enzyme (encoded by the purD gene). The purD genes often contain PurD RNA motif in their 5' UTR. In yeast, GARS is part of a bifunctional enzyme (encoded by the ADE5/7 gene) in conjunction with phosphoribosylformylglycinamidine cyclo-ligase (AIRS). In higher eukaryotes, including humans, GARS is part of a trifunctional enzyme in conjunction with AIRS and with phosphoribosylglycinamide formyltransferase (GART), forming GARS- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trifunctional Purine Biosynthetic Protein Adenosine-3
Trifunctional purine biosynthetic protein adenosine-3 is an enzyme that in humans is encoded by the ''GART'' gene. This protein is a trifunctional polypeptide. It has Phosphoribosylamine—glycine ligase (EC 6.3.4.13), Phosphoribosylglycinamide formyltransferase (EC 2.1.2.2), AIR synthetase (FGAM cyclase) (EC 6.3.3.1) activity which is required for de novo purine Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which includ ... biosynthesis. References Further reading * * * * * * * * * * * * * * * * * * * * External links * {{Protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAR Transformylase
Phosphoribosylglycinamide formyltransferase (, ''2-amino-N-ribosylacetamide 5'-phosphate transformylase'', ''GAR formyltransferase'', ''GAR transformylase'', ''glycinamide ribonucleotide transformylase'', ''GAR TFase'', ''5,10-methenyltetrahydrofolate:2-amino-N-ribosylacetamide ribonucleotide transformylase'') is an enzyme with systematic name ''10-formyltetrahydrofolate:5'-phosphoribosylglycinamide N-formyltransferase''. This enzyme catalyses the following chemical reaction : 10-formyltetrahydrofolate + N1-(5-phospho-D-ribosyl)glycinamide \rightleftharpoons tetrahydrofolate + N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide This THF dependent enzyme catalyzes a nucleophilic acyl substitution of the formyl group from 10-formyltetrahydrofolate (fTHF) to N1-(5-phospho-D-ribosyl)glycinamide (GAR) to form N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide (fGAR) as shown above. This reaction plays an important role in the formation of purine through the ''de novo'' purine biosynthesis pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Down Syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. The average IQ of a young adult with Down syndrome is 50, equivalent to the mental ability of an eight- or nine-year-old child, but this can vary widely. The parents of the affected individual are usually genetically normal. The probability increases from less than 0.1% in 20-year-old mothers to 3% in those of age 45. The extra chromosome is believed to occur by chance, with no known behavioral activity or environmental factor that changes the probability. Down syndrome can be identified during pregnancy by prenatal screening followed by diagnostic testing or after birth by direct observation and genetic testing. Since the introduction of screening, Down syndrome pregnancies are often abor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Adenosine Monophosphate
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway. History Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP). Synthesis Cyclic adenosine monophosphate, AMP is synthesized from Adenosine triphosphate, ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. Adenylate cyclase is ''activated'' by a range of signaling molecules through the activation of adenylate cyclase stimulatory G (Gs alpha subunit, Gs)-protein-coupled recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flavin Adenine Dinucleotide
Flavin may refer to: Placename * Flavin, Aveyron, a commune in southern France Surname * Adrian Flavin (born 1979), a professional rugby player * Christopher Flavin, president of the Worldwatch Institute * Dan Flavin (1933–1996), a minimalist artist famous for using fluorescent light fixtures * Dan Flavin (politician), Louisiana politician * James Flavin (1906–1976), an American character actor * Jennifer Flavin (born 1968), a former model and wife of actor Sylvester Stallone * Martin Flavin (1883–1967), an American playwright and novelist * Martin Flavin (politician) (1841–1917), Irish Nationalist politician, Member of Parliament (MP) for Cork, 1891–1892 * Michael Joseph Flavin (1866-1944), Irish Nationalist politician, Member of Parliament (MP) for North Kerry, 1896-1918 * Mick Flavin, an Irish country singer Biochemistry * Flavin adenine dinucleotide (FAD), a redox cofactor * Flavin-containing amine oxidoreductase, a family of amine oxidases * Flavin-containing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guanosine Monophosphate
Guanosine monophosphate (GMP), also known as 5′-guanidylic acid or guanylic acid (conjugate base guanylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside guanosine. GMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase guanine; hence it is a ribonucleoside monophosphate. Guanosine monophosphate is commercially produced by microbial fermentation. As an acyl substituent, it takes the form of the prefix guanylyl-. ''De novo'' synthesis GMP synthesis starts with D-ribose 5′-phosphate, a product of the pentose phosphate pathway. The synthesis proceeds by the gradual formation of the purine ring on carbon-1 of ribose, with CO2, glutamine, glycine, aspartate and one-carbon derivatives of tetrahydrofolate donating various elements towards the building of the ring As inhibitor of guanosine monophosphate synthesis in experimental models, the glutamine analogue DON can be used.''Ahluwalia GS et alMet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
