Pseudomonas putida F1 can grow with toluene as its sole source of carbon and energy. The initial reaction of the degradation of toluene is catalyzed by a three-component toluene dioxygenase enzyme system consisting of a reductase (ReductaseTOL), a ferredoxin (FerredoxinTOL) and a Rieske non-heme iron dioxygenase (OxygenaseTOL). The three components and the apoenzyme of the dioxygenase (apo-OxygenaseTOL) were overexpressed, purified and crystallized. ReductaseTOL diffracts to 1.8 A and belongs to space group P4(1)2(1)2, with unit-cell parameters a = b = 77.1, c = 156.3 A. Ferredoxin(TOL) diffracts to 1.2 A and belongs to space group P2(1), with unit-cell parameters a = 30.5, b = 52.0, c = 30.95 A, beta = 113.7 degrees. Apo-OxygenaseTOL and OxygenaseTOL diffract to 3.2 A and belong to space group P4(3)32, with unit-cell parameters a = 235.9 A and a = 234.5 A, respectively.