We have determined structures of naphthalene dioxygenase that show a molecular oxygen species bound to the mononuclear iron in a side-on fashion.

The structures reported here provide the basis for a reaction mechanism and for the high stereospecificity of the reaction catalyzed by naphthalene dioxygenase.

Bacterial strains expressing toluene and naphthalene dioxygenase were used to examine the sequence of reactions involved in the oxidation of 1,2-dihydronaphthalene.