Rieske non-heme iron oxygenase (RO) family, Nathphalene 1,2-dioxygenase (NDO) subfamily, N-terminal Rieske domain of the oxygenase alpha subunit; ROs comprise a large class of aromatic ring-hydroxylating dioxygenases that enable microorganisms to tolerate and utilize aromatic compounds for growth. The oxygenase alpha subunit contains an N-terminal Rieske domain with an [2Fe-2S] cluster and a C-terminal catalytic domain with a mononuclear Fe(II) binding site. The Rieske [2Fe-2S] cluster accepts electrons from a reductase or ferredoxin component and transfers them to the mononuclear iron for catalysis. NDO is a three-component RO system consisting of a reductase, a ferredoxin, and a hetero-hexameric alpha-beta subunit oxygenase component. NDO catalyzes the oxidation of naphthalene to cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene (naphthalene cis-dihydrodiol) with the consumption of O2 and NAD(P)H. NDO has a relaxed substrate specificity and can oxidize almost 100 substrates. Included in its varied activities are the enantiospecific cis-dihydroxylation of polycyclic aromatic hydrocarbons and benzocycloalkenes, benzylic hydroxylation, N- and O-dealkylation, sulfoxidation and desaturation reactions.