Ferrous iron is inserted into protoporphyrin IX to form heme Authored: Jassal, B, D'Eustachio, P, 2007-01-24 10:19:49 EC Number: 4.99.1.1 Edited: Jassal, B, D'Eustachio, P, 2007-01-24 10:19:49 Ferrochelatase (FECH) catalyzes the insertion of ferrous iron into protoporphyrin IX to form heme. FECH is localized on the matrix surface of the inner mitochondrial membrane and this reaction takes place within the mitochondrial matrix. The enzyme functions as a homodimer with each monomer containing a nitric oxide-sensitive 2Fe-2S cluster. Enzyme deficiency is associated with erythropoietic protoporphyria in vivo, and inhibition of ferrochelatase activity is a clinically important consequence of lead poisoning (Piomelli et al. 1987). Pubmed11175906 Pubmed3327432 Reactome Database ID Release 43189465 Reactome, http://www.reactome.org ReactomeREACT_9461 Reviewed: Sassa, S, 2007-01-24 10:18:36 has a Stoichiometric coefficient of 2