Abstract
A purification procedure was developed to stabilize the iron-sulphur proteins of the benzene dioxygenase system from Pseudomonas putida. The intermediate electron-carrying protein has a mol. wt. of 12300 and possesses one (2Fe–2S) cluster, whereas the terminal dioxygenase has a mol.wt. of 215300 and possesses two (2Fe–2S) clusters. The order and stoicheiometry of electron transfer and of the whole system are described.