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In enzymology, a 3-dehydroquinate synthase () is an enzyme that catalyzes the chemical reaction :3-deoxy-arabino-heptulosonate 7-phosphate 3-dehydroquinate + phosphate Hence, this enzyme has one substrate, 3-deoxy-arabino-heptulosonate 7-phosphate, and two products, 3-dehydroquinate and phosphate. The protein uses NAD+ to catalyze the reaction. This reaction is part of the shikimate pathway which is involved in the biosynthesis of aromatic amino acids. 3-Dehydroquinate synthase belongs to the family of lyases, to be specific those carbon-oxygen lyases acting on phosphates. This enzyme participates in phenylalanine, tyrosine, and tryptophan biosynthesis. It employs one cofactor, cobalt. ==Background== The shikimate pathway is composed of seven steps, each catalyzed by an enzyme. The shikimate pathway is responsible for producing the precursors for aromatic amino acids, which are essential to our diets because we cannot synthesize them in our bodies. Only plants, bacteria, and microbial eukaryotes are capable of producing aromatic amino acids. The pathway ultimately converts phosphoenolpyruvate and 4-erythrose phosphate into chorismate, the precursor to aromatic amino acids. 3-Dehydroquinate synthase is the enzyme that catalyzes reaction in the second step of this pathway. This second step of the reaction eliminates a phosphate from 3-deoxy-D-arabino-heptulosonate 7-phosphate, which results in 3-dehydroquinate. 3-Dehydroquinate synthase is a monomeric enzyme, and has a molecular weight of 39,000. 3-dehydroquinate synthase is activated by inorganic phosphate, and requires NAD+ for activity, although the reaction in total is neutral when catalyzed by an enzyme.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「3-dehydroquinate synthase」の詳細全文を読む スポンサード リンク
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