3b9j | pdb_00003b9j

Structure of Xanthine Oxidase with 2-hydroxy-6-methylpurine

spinqualitylabelsall models 3b9j, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3b9j is a 6 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 290, CA, FAD, FES, MOS, MTE Activity: Xanthine oxidase, with EC number 1.17.3.2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [XDH_BOVIN] Key enzyme in purine degradation. Catalyzes the oxidation of hypoxanthine to xanthine. Catalyzes the oxidation of xanthine to uric acid. Contributes to the generation of reactive oxygen species. 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 Xanthine oxidoreductase catalyzes the final two steps of purine catabolism and is involved in a variety of pathological states ranging from hyperuricemia to ischemia-reperfusion injury. The human enzyme is expressed primarily in its dehydrogenase form utilizing NAD+ as the final electron acceptor from the enzyme's flavin site but can exist as an oxidase that utilizes O2 for this purpose. Central to an understanding of the enzyme's function is knowledge of purine substrate orientation in the enzyme's molybdenum-containing active site. We report here the crystal structure of xanthine oxidase, trapped at the stage of a critical intermediate in the course of reaction with the slow substrate 2-hydroxy-6-methylpurine at 2.3A. This is the first crystal structure of a reaction intermediate with a purine substrate that is hydroxylated at its C8 position as is xanthine and confirms the structure predicted to occur in the course of the presently favored reaction mechanism. The structure also corroborates recent work suggesting that 2-hydroxy-6-methylpurine orients in the active site with its C2 carbonyl group interacting with Arg-880 and extends our hypothesis that xanthine binds opposite this orientation, with its C6 carbonyl positioned to interact with Arg-880 in stabilizing the MoV transition state. Substrate orientation in xanthine oxidase: crystal structure of enzyme in reaction with 2-hydroxy-6-methylpurine.,Pauff JM, Zhang J, Bell CE, Hille R J Biol Chem. 2008 Feb 22;283(8):4818-24. Epub 2007 Dec 6. PMID:18063585 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Xanthine dehydrogenase

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