FIG. 1.

Schematic depiction of the components of a Rieske oxygenase system. Electrons from NAD(P)H are extracted by the reductase and then transferred to the ferredoxin. The ferredoxin transfers these electrons to the Rieske cluster of the oxygenase. In two-component systems, the reductase directly transfers electrons to the oxygenase. The oxygenase binds molecular oxygen and an aromatic substrate in the active site of the mononuclear domain. Electrons are transferred from the oxygenase Rieske cluster to the mononuclear iron, and an oxidized product is formed. The image was made using biphenyl ferredoxin reductase (Protein Data Bank no. 1F3P), biphenyl reductase ferredoxin (Protein Data Bank no. 1FQT), and naphthalene dioxygenase (Protein Data Bank no. 1NDO).