1dxo

Crystal structure of human NAD[P]H-QUINONE oxidoreductase CO with 2,3,5,6,tetramethyl-P-benzoquinone (duroquinone) at 2.5 Angstrom resolution

spinqualitylabelsall models 1dxo, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1dxo is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: DQN, FAD Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function NQO1_HUMAN The enzyme apparently serves as a quinone reductase in connection with conjugation reactions of hydroquinons involved in detoxification pathways as well as in biosynthetic processes such as the vitamin K-dependent gamma-carboxylation of glutamate residues in prothrombin synthesis. 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 PubMed NAD(P)H/quinone acceptor oxidoreductase (QR1, NQO1, formerly DT-diaphorase; EC ) protects animal cells from the deleterious and carcinogenic effects of quinones and other electrophiles. In this paper we report the apoenzyme structures of human (at 1.7-A resolution) and mouse (2.8 A) QR1 and the complex of the human enzyme with the substrate duroquinone (2.5 A) (2,3,5, 6-tetramethyl-p-benzoquinone). In addition to providing a description and rationale of the structural and catalytic differences among several species, these structures reveal the changes that accompany substrate or cofactor (NAD) binding and release. Tyrosine-128 and the loop spanning residues 232-236 close the binding site, partially occupying the space left vacant by the departing molecule (substrate or cofactor). These changes highlight the exquisite control of access to the catalytic site that is required by the ping-pong mechanism in which, after reducing the flavin, NAD(P)(+) leaves the catalytic site and allows substrate to bind at the vacated position. In the human QR1-duroquinone structure one ring carbon is significantly closer to the flavin N5, suggesting a direct hydride transfer to this atom. Structures of recombinant human and mouse NAD(P)H:quinone oxidoreductases: species comparison and structural changes with substrate binding and release.,Faig M, Bianchet MA, Talalay P, Chen S, Winski S, Ross D, Amzel LM Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3177-82. PMID:10706635 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Quinone reductase Quinone reductase 3D structures

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