1vnc
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CHLOROPEROXIDASE FROM THE FUNGUS CURVULARIA INAEQUALIS
OverviewOverview
The chloroperoxidase (EC 1.11.1.-) from the fungus Curvularia inaequalis belongs to a class of vanadium enzymes that oxidize halides in the presence of hydrogen peroxide to the corresponding hypohalous acids. The 2.1 A crystal structure (R = 20%) of an azide chloroperoxidase complex reveals the geometry of the catalytic vanadium center. Azide coordinates directly to the metal center, resulting in a structure with azide, three nonprotein oxygens, and a histidine as ligands. In the native state vanadium will be bound as hydrogen vanadate(V) in a trigonal bipyramidal coordination with the metal coordinated to three oxygens in the equatorial plane, to the OH group at one apical position, and to the epsilon 2 nitrogen of a histidine at the other apical position. The protein fold is mainly alpha-helical with two four-helix bundles as main structural motifs and an overall structure different from other structures. The helices pack together to a compact molecule, which explains the high stability of the protein. An amino acid sequence comparison with vanadium-containing bromoperoxidase from the seaweed Ascophyllum nodosum shows high similarities in the regions of the metal binding site, with all hydrogen vanadate(V) interacting residues conserved except for lysine-353, which is an asparagine.
About this StructureAbout this Structure
1VNC is a Single protein structure of sequence from Curvularia inaequalis with and as ligands. Active as Chloride peroxidase, with EC number 1.11.1.10 Full crystallographic information is available from OCA.
ReferenceReference
X-ray structure of a vanadium-containing enzyme: chloroperoxidase from the fungus Curvularia inaequalis., Messerschmidt A, Wever R, Proc Natl Acad Sci U S A. 1996 Jan 9;93(1):392-6. PMID:8552646
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