Structure and function of type I copper in multicopper oxidases.
The type I copper center in multicopper oxidases is constructed from 1Cys2His and weakly coordinating 1Met or the non-coordinating 1Phe/1Leu, and it exhibits spectral properties and an alkaline transition similar to those of the blue copper center in blue copper proteins. Since the type I copper center in multicopper oxidases is deeply buried inside the protein molecule, electron transfers to and from type I copper are performed through specific pathways: the hydrogen bond between an amino acid located at the substrate binding site and a His residue coordinating type I copper, and the His-Cys-His sequence connecting the type I copper center and the trinuclear copper center comprised of a type II copper and a pair of type III coppers. The intramolecular electron transfer rates can be tuned by mutating the fourth ligand of type I copper. Further, mutation at the Cys ligand gives a vacant type I copper center and traps the reaction intermediate during the four-electron reduction of dioxygen.
Sakurai
T
T
Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan. ts0513@kenroku.kanazawa-u.ac.jp
Kataoka
K
K
D001665:Binding Sites; D003300:Copper / Q000737:chemistry*; D004579:Electron Transport; D010088:Oxidoreductases / Q000737:chemistry*; D013057:Spectrum Analysis; D013379:Substrate Specificity
D003300:Copper; D010088:Oxidoreductases; C024748:copper oxidase