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From Proteopedia
Crystal Structure of Quercetin 2,3-dioxygenase
Overview
Quercetin 2,3-dioxygenase is a copper-containing enzyme that catalyzes the insertion of molecular oxygen into polyphenolic flavonols. Dioxygenation catalyzed by iron-containing enzymes has been studied extensively, but dioxygenases employing other metal cofactors are poorly understood. We determined the crystal structure of quercetin 2,3-dioxygenase at 1.6 A resolution. The enzyme forms homodimers, which are stabilized by an N-linked heptasaccharide at the dimer interface. The mononuclear type 2 copper center displays two distinct geometries: a distorted tetrahedral coordination, formed by His66, His68, His112, and a water molecule, and a distorted trigonal bipyramidal environment, which additionally comprises Glu73. Manual docking of the substrate quercetin into the active site showed that the different geometries of the copper site might be of catalytic importance.
About this Structure
Full crystallographic information is available from OCA.
Reference
Crystal structure of the copper-containing quercetin 2,3-dioxygenase from Aspergillus japonicus., Fusetti F, Schroter KH, Steiner RA, van Noort PI, Pijning T, Rozeboom HJ, Kalk KH, Egmond MR, Dijkstra BW, Structure. 2002 Feb;10(2):259-68. PMID:11839311 Page seeded by OCA on Fri May 2 21:56:29 2008
