page_title: Ferrochelatase
section_title: Function
hierarchical_section_title: Ferrochelatase / Function
context_page_description: Ferrochelatase is an enzyme that is encoded by the FECH gene in humans. Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B. It catalyses the reaction:
  protoporphyrin + Fe⁺² ⇌ heme B + 2 H⁺
context_section_description: Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX in the heme biosynthesis pathway to form heme B. The enzyme is localized to the matrix-facing side of the inner mitochondrial membrane. Ferrochelatase is the best known member of a family of enzymes that add divalent metal cations to tetrapyrrole structures. For example, magnesium chelatase adds magnesium to protoporphyrin IX in the first step of bacteriochlorophyll biosynthesis.
  Heme B is an essential cofactor in many proteins and enzymes. In particular, heme b plays a key role as the oxygen carrier in hemoglobin in red blood cells and myoglobin in muscle cells. Furthermore, heme B is found in cytochrome b, a key component in Q-cytochrome c oxidoreductase (complex III) in oxidative phosphorylation.
caption: Summary of heme B biosynthesis—note that some reactions occur in the cytoplasm and some in the mitochondrion (yellow)
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