BINUCLEAR IRON CENTERS IN PROTEINS

Binuclear iron sites with bridging ligands feature in a number of important non-haem iron proteins. Haemerythrin is the respiratory protein in marine worms. In addition, there are the enzymes ribonucleotide reductase, important in DNA synthesis; purple acid phosphatases with as yet unknown function; and methane monooxygenase, from methanotropic bacteria, which catalyses the insertion of O into C-H bonds. The variety of techniques used in their structural characterization is described from an historical viewpoint. Finally, the reactivity and mechanisms of action of these proteins are briefly discussed.