Component of the p-cumate 2,3-dioxygenase multicomponent enzyme system which catalyzes the incorporation of both atoms of molecular oxygen into p-cumate to form cis-2,3-dihydroxy-2,3-dihydro-p-cumate. Ferredoxin reductase catalyzes the transfer of electrons from NADH to ferredoxin (CmtAd). H(+) + NAD(+) + 2 reduced [2Fe-2S]-[ferredoxin] = NADH + 2 oxidized [2Fe-2S]-[ferredoxin] Aromatic compound metabolism; p-cumate degradation; acetaldehyde and pyruvate from p-cumate. The p-cumate 2,3-dioxygenase 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 (CmtAa) and a ferredoxin (CmtAd), and the dioxygenase component is formed of a large alpha subunit (CmtAb) and a small beta subunit (CmtAc). Induced by p-cumate and repressed by CymR. Belongs to the FAD-dependent oxidoreductase family.