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:''This enzyme is not to be confused with Bisphosphoglycerate mutase which catalyzes the conversion of 1,3-bisphosphoglycerate to 2,3-bisphosphoglycerate.'' Phosphoglycerate mutase (PGM) is an enzyme that catalyzes step 8 of glycolysis. It catalyzes the internal transfer of a phosphate group from C-3 to C-2 which results in the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG) through a 2,3-bisphosphoglycerate intermediate. These enzymes are categorized into the two distinct classes of either cofactor-dependent (dPGM) or cofactor-independent (iPGM). The dPGM enzyme () is composed of approximately 250 amino acids and is found in all vertebrates as well as in some invertebrates, fungi, and bacteria. The iPGM () class is found in all plants and algae as well as in some invertebrate, fungi, and Gram-positive bacteria. This class of PGM enzyme shares the same superfamily as alkaline phosphatase. ==Mechanism== PGM is an isomerase enzyme, effectively transferring a phosphate group (PO32−) from the C-3 carbon of 3-phosphoglycerate to the C-2 carbon forming 2-phosphoglycerate. There are a total of three reactions dPGM can catalyze: a mutase reaction resulting in the conversion of 3PG to 2PG and vice versa, a phosphatase reaction creating phosphoglycerate from 2,3-bisphosphoglycerate, and a synthase reaction producing 2,3-bisphosphoglycerate from 1,3-bisphosphoglycerate similar to the enzyme bisphosphoglycerate mutase. Kinetic and structural studies have provided evidence that indicate dPGM and bisphosphoglycerate mutase are paralogous structures.〔 Both enzymes are contained in the superfamily that also contains the phosphatase portion of phosphofructokinase 2 and prostatic acid phosphatase. The catalyzed mutase reaction involves two separate phosphoryl groups and the ending phosphate on the 2-carbon is not the same phosphate removed from the 3-carbon. In the cofactor-dependent enzyme's initial state, the active site contains a phosphohistidine complex formed by phosphorylation of a specific histidine residue. When 3-phosphoglycerate enters the active site, the phosphohistidine complex is positioned as to facilitate transfer of phosphate from enzyme to substrate C-2 creating a 2,3-bisphosphoglycerate intermediate. Dephosphorylation of the enzyme histidine actuates a local allosteric change in enzyme configuration which now aligns the substrates 3-C phosphate group with enzyme active site histidine and facilitates phosphate transfer returning the enzyme to its initial phosphorylated state and releasing product 2-phosphoglycerate. 2,3-bisphosphoglycerate is required a cofactor for dPGM. In contrast, the iPGM class is independent of 2,3-bisphosphoglycerate and catalyzes the intramolecular transfer of the phosphate group on monophosphoglycerates using a phosphoserineintermediate. 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「phosphoglycerate mutase」の詳細全文を読む スポンサード リンク
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