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Glutathione transferase zeta/maleylacetoacetate isomeraseGlutathione transferase zeta/maleylacetoacetate isomerase
Structural highlights
Function[MAAI_HUMAN] Bifunctional enzyme showing minimal glutathione-conjugating activity with ethacrynic acid and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and maleylacetoacetate isomerase activity. Has also low glutathione peroxidase activity with T-butyl and cumene hydroperoxides. Is able to catalyze the glutathione dependent oxygenation of dichloroacetic acid to glyoxylic acid.[1] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMaleylacetoacetate isomerase (MAAI), a key enzyme in the metabolic degradation of phenylalanine and tyrosine, catalyzes the glutathione-dependent isomerization of maleylacetoacetate to fumarylacetoacetate. Deficiencies in enzymes along the degradation pathway lead to serious diseases including phenylketonuria, alkaptonuria, and the fatal disease, hereditary tyrosinemia type I. The structure of MAAI might prove useful in the design of inhibitors that could be used in the clinical management of the latter disease. Here we report the crystal structure of human MAAI at 1.9 A resolution in complex with glutathione and a sulfate ion which mimics substrate binding. The enzyme has previously been shown to belong to the zeta class of the glutathione S-transferase (GST) superfamily based on limited sequence similarity. The structure of MAAI shows that it does adopt the GST canonical fold but with a number of functionally important differences. The structure provides insights into the molecular bases of the remarkable array of different reactions the enzyme is capable of performing including isomerization, oxygenation, dehalogenation, peroxidation, and transferase activity. Crystal structure of maleylacetoacetate isomerase/glutathione transferase zeta reveals the molecular basis for its remarkable catalytic promiscuity.,Polekhina G, Board PG, Blackburn AC, Parker MW Biochemistry. 2001 Feb 13;40(6):1567-76. PMID:11327815[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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