 This radical then couples to the hydroxide ligand, producing the hydroxylated product and the Fe(II) resting state of the enzyme.The Rieske dioxygenases catalyze the cis-dihydroxylation of arenes to cis-dihydro-diol products.These enzymes are prominently found in soil bacteria such as "Pseudomonas", and their reactions constitute the initial step in aromatic hydrocarbon biodegradation.