InterPro domain: IPR008922

Copper active sites play a major role in biological dioxygen activation. Oxygen intermediates have been studied in detail for the proteins and enzymes involved in reversible O2 binding (hemocyanin), activation (tyrosinase), and four-electron reduction to water (multicopper oxidases). Tyrosinase binds two copper ions (CuA and CuB). Each of the two copper ions has been shown to be bound by three conserved histidine residues. The regions around these copper-binding ligands are well-conserved and also shared by some hemocyanins, which are copper-containing oxygen carriers from the hemolymph of many molluscs and arthropods [ 1 ].

1. Oxygen Binding, Activation, and Reduction to Water by Copper Proteins. Angew. Chem. Int. Ed. Engl. 40, 4570-4590