1idq
CRYSTAL STRUCTURE OF NATIVE VANADIUM-CONTAINING CHLOROPEROXIDASE FROM CURVULARIA INAEQUALIS
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OverviewOverview
Implications for the catalytic mechanism of the vanadium-containing chloroperoxidase from the fungus Curvularia inaequalis have been obtained from the crystal structures of the native and peroxide forms of the enzyme.The X-ray structures have been solved by difference Fourier techniques using the atomic model of the azide chloroperoxidase complex. The 2.03 A crystal structure (R = 19.7%) of the native enzyme reveals the geometry of the intact catalytic vanadium center. The vanadium is coordinated by four non-protein oxygen atoms and one nitrogen (NE2) atom from histidine 496 in a trigonal bipyramidal fashion. Three oxygens are in the equatorial plane and the fourth oxygen and the nitrogen are at the apexes of the bipyramid. In the 2.24 A crystal structure (R = 17.7%) of the peroxide derivate the peroxide is bound to the vanadium in an eta2-fashion after the release of the apical oxygen ligand. The vanadium is coordinated also by 4 non-protein oxygen atoms and one nitrogen (NE2) from histidine 496. The coordination geometry around the vanadium is that of a distorted tetragonal pyramid with the two peroxide oxygens, one oxygen and the nitrogen in the basal plane and one oxygen in the apical position. A mechanism for the catalytic cycle has been proposed based on these X-ray structures and kinetic data.
About this StructureAbout this Structure
1IDQ is a Single protein structure of sequence from Curvularia inaequalis with as ligand. Active as Chloride peroxidase, with EC number 1.11.1.10 Full crystallographic information is available from OCA.
ReferenceReference
Implications for the catalytic mechanism of the vanadium-containing enzyme chloroperoxidase from the fungus Curvularia inaequalis by X-ray structures of the native and peroxide form., Messerschmidt A, Prade L, Wever R, Biol Chem. 1997 Mar-Apr;378(3-4):309-15. PMID:9165086
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