Alkene monooxygenase (AMO) fromRhodococcus rhodochrous(formerly Nocardia corallina) B-276 belongs to a family of multicomponent nonheme binuclear iron-centre oxygenases that includes the soluble methane mono-oxygenases (sMMOs) found in some methane-oxidizing bacteria. The enzymes catalyse the insertion of oxygen into organic substrates (mostly hydrocarbons) at the expense of O2and NAD(P)H.