cl17299

Heme oxygenase catalyzes the rate limiting step in the degradation of heme to bilirubin, it is essential for recycling of iron from heme. Heme is used as a substrate and cofactor for its own degradation to biliverdin, iron, and carbon monoxide. This family includes bacterial HO, as well as the mammalian isoforms HO-1, and HO-2. Heme oxygenases play key roles in heme homeostasis, oxidative stress response, photosynthetic pigment formation in cyanobacteria, cellular signaling in mammals, and iron acquisition from host heme by bacterial pathogens.