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In enzymology, a protein-glutamate methylesterase () is an enzyme that catalyzes the chemical reaction :protein L-glutamate O5-methyl ester + H2O protein L-glutamate + methanol Thus, the two substrates of this enzyme are protein L-glutamate O5-methyl ester and H2O, whereas its two products are protein L-glutamate and methanol. This enzyme is a demethylase, and more specifically it belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is protein-L-glutamate-O5-methyl-ester acylhydrolase. Other names in common use include chemotaxis-specific methylesterase, methyl-accepting chemotaxis protein methyl-esterase, CheB methylesterase, methylesterase CheB, protein methyl-esterase, protein carboxyl methylesterase, PME, protein methylesterase, and protein-L-glutamate-5-O-methyl-ester acylhydrolase. This enzyme participates in 3 metabolic pathways: two-component system - general, bacterial chemotaxis - general, and bacterial chemotaxis - organism-specific. CheB is part of a two-component signal transduction system. These systems enable bacteria to sense, respond, and adapt to a wide range of environments, stressors, and growth conditions. Two-component systems are composed of a sensor histidine kinase (HK) and its cognate response regulator (RR). The HK catalyses its own autophosphorylation followed by the transfer of the phosphoryl group to the receiver domain on RR; phosphorylation of the RR usually activates an attached output domain, in this case a methyltransferase domain. CheB is involved in chemotaxis. CheB methylesterase is responsible for removing the methyl group from the gamma-glutamyl methyl ester residues in the methyl-accepting chemotaxis proteins (MCP). CheB is regulated through phosphorylation by CheA. The N-terminal region of the protein is similar to that of other regulatory components of sensory transduction systems. ==Structural studies== As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes and . 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「Protein-glutamate methylesterase」の詳細全文を読む スポンサード リンク
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