1juh
From Proteopedia
Crystal Structure of Quercetin 2,3-dioxygenase
Structural highlights
FunctionQDOI_ASPJA Performs the first step in the degradation of the flavonoid quercetin by a dioxygenase reaction. The enzyme catalyzes the cleavage of the O-heteroaromatic ring of the flavonol quercetin yielding the depside 2-protocatechuoyl-phloroglucinol carboxylic acid and carbon monoxide. This involves the remarkable dioxygenolytic cleavage of two carbon-carbon bonds. 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 PubMedQuercetin 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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