The α Subunit of Toluene Dioxygenase from Pseudomonas putida F1 Can Accept Electrons from Reduced Ferredoxin(TOL) but Is Catalytically Inactive in the Absence of the β Subunit

The oxygenase component of toluene dioxygenase from Pseudomonas putida F1 is an iron-sulfur protein (ISP(TOL)) consisting of α (TodC1) and β (TodC2) subunits. Purified TodC1 gave absorbance and electron paramagnetic resonance spectra identical to those given by purified ISP(TOL). TodC1 was reduced by NADH and catalytic amounts of Reductase(TOL) and Ferredoxin(TOL). Reduced TodC1 did not oxidize toluene, and catalysis was strictly dependent on the presence of purified TodC2.