FIG 1.
Scheme of the monooxygenase cycle of UPO, including resting state (RS) (FeIII upper coordination position occupied by a water molecule), compound 0 (Cpd-0) (FeIII-hydroperoxo complex), compound I (Cpd-I) (FeIV-oxo/porphyrin cation radical complex), and compound II (Cpd-II) (FeIV-hydroxo complex), resulting in substrate (R-H) conversion into hydroxylated product (R-OH) at the expense of hydrogen peroxide being reduced to water (with its second oxygen atom being transferred to the substrate) (adapted from reference 1).