4hk7

Crystal structure of Cordyceps militaris IDCase in complex with uracil

spinqualitylabelsall models 4hk7, resolution 2.19Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4hk7 is a 4 chain structure with sequence from Cordyceps militaris. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: URA, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G3J531_CORMM Publication Abstract from PubMed DNA methylation and demethylation regulate many crucial biological processes in mammals and are linked to many diseases. Active DNA demethylation is believed to be catalyzed by TET proteins and a putative DNA decarboxylase that may share some similarities in sequence, structure and catalytic mechanism with isoorotate decarboxylase (IDCase) that catalyzes decarboxylation of 5caU to U in fungi. We report here the structures of wild-type and mutant IDCases from Cordyceps militaris and Metarhizium anisopliae in apo form or in complexes with 5caU, U, and an inhibitor 5-nitro-uracil. IDCases adopt a typical (beta/alpha)8 barrel fold of the amidohydrolase superfamily and function as dimers. A Zn2+ is bound at the active site and coordinated by four strictly conserved residues, one Asp and three His. The substrate is recognized by several strictly conserved residues. The functional roles of the key residues at the active site are validated by mutagenesis and biochemical studies. Based on the structural and biochemical data, we present for the first time a novel catalytic mechanism of decarboxylation for IDCases, which might also apply to other members of the amidohydrolase superfamily. In addition, our biochemical data show that IDCases can catalyze decarboxylation of 5caC to C albeit with weak activity, which is the first in vitro evidence for direct decarboxylation of 5caC to C by an enzyme. These findings are valuable in the identification of potential DNA decarboxylase in mammals.Cell Research advance online publication 6 August 2013; doi:10.1038/cr.2013.107. Crystal structures of isoorotate decarboxylases reveal a novel catalytic mechanism of 5-carboxyl-uracil decarboxylation and shed light on the search for DNA decarboxylase.,Xu S, Li W, Zhu J, Wang R, Li Z, Xu GL, Ding J Cell Res. 2013 Aug 6. doi: 10.1038/cr.2013.107. PMID:23917530 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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