has participant water hydron dioxygen carbon monoxide iron(2+) FMNH2(2-) biliverdin(2-) FMN(3-) ferroheme b(2-) heme oxygenase (decyclizing) activity https://github.com/geneontology/go-ontology/issues/21106 heme oxidase activity EC:1.14.14.18 Catalysis of the reaction: heme b + 3 O2 + 3 reduced [NADPH-hemoprotein reductase] = biliverdin + CO + Fe2+ + H+ + 3 H2O + 3 oxidized [NADPH-hemoprotein reductase]. haem oxidase activity haem oxygenase (decyclizing) activity GO:0004392 MetaCyc:HEME-OXYGENASE-DECYCLIZING-RXN heme,hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating) molecular_function RHEA:21764 heme oxygenase activity haem oxygenase activity ORP33 proteins Reactome:R-HSA-189398 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen