Component of the 2,4-dinitrotoluene dioxygenase (DNTDO) multicomponent enzyme system which catalyzes the incorporation of both atoms of molecular oxygen into 2,4-dinitrotoluene (DNT) to form 4-methyl-5-nitrocatechol (MNC) and nitrite. Ferredoxin reductase catalyzes the transfer of electrons from NADH to ferredoxin (DntAb). Also able to convert naphthalene to cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. H(+) + NAD(+) + 2 reduced [2Fe-2S]-[ferredoxin] = NADH + 2 oxidized [2Fe-2S]-[ferredoxin] Binds 1 2Fe-2S cluster. The 2,4-dinitrotoluene dioxygenase (DNTDO) multicomponent enzyme system is composed of an electron transfer component and a dioxygenase component (iron sulfur protein (ISP)). The electron transfer component is composed of a ferredoxin reductase (DntAa) and a ferredoxin (DntAb), and the dioxygenase component is formed of a large alpha subunit (DntAc) and a small beta subunit (DntAd). Belongs to the bacterial ring-hydroxylating dioxygenase ferredoxin reductase component family.