Human ferrochelatase, found at the mitochondrial inner membrane inner surface, was shown in an active recombinant form to be a homodimer. This contrasts to an earlier finding by gel filtration that overexpressed E. coli ferrochelatase runs as a monomer. [Biosynthesis of cofactors, prosthetic groups, and carriers, Heme, porphyrin, and cobalamin]
Jiyao W et al.(2023). "The conserved domain database in 2023.",