3hcr is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
HEMH_HUMAN Defects in FECH are the cause of erythropoietic protoporphyria (EPP) [MIM:177000. Porphyrias are inherited defects in the biosynthesis of heme, resulting in the accumulation and increased excretion of porphyrins or porphyrin precursors. They are classified as erythropoietic or hepatic, depending on whether the enzyme deficiency occurs in red blood cells or in the liver. EPP is a form of porphyria marked by excessive protoporphyrin in erythrocytes, plasma, liver and feces, and by widely varying photosensitive skin changes ranging from a burning or pruritic sensation to erythema, edema and wheals.[1][2][3][4][5][6][7][8][9][10][11][12]
Function
HEMH_HUMAN Catalyzes the ferrous insertion into protoporphyrin IX.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Ferrochelatase (protoheme ferrolyase, E.C. 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Within the past two years, X-ray crystallographic data obtained with human ferrochelatase have clearly shown that significant structural changes occur during catalysis that are predicted to facilitate metal insertion and product release. One unanswered question about ferrochelatase involves defining the mechanism whereby some metals, such as divalent Fe, Co, Ni, and Zn, can be used by the enzyme in vitro to produce the corresponding metalloporphyrins, while other metals, such as divalent Mn, Hg, Cd, or Pb, are inhibitors of the enzyme. Through the use of high-resolution X-ray crystallography along with characterization of metal species via their anomalous diffraction, the identity and position of Hg, Cd, Ni, or Mn in the center of enzyme-bound porphyrin macrocycle were determined. When Pb, Hg, Cd, or Ni was present in the macrocycle, the conserved pi helix was in the extended, partially unwound "product release" state. Interestingly, in the structure of ferrochelatase with Mn-porphyrin bound, the pi helix is not extended or unwound and is in the "substrate-bound" conformation. These findings show that at least in the cases of Mn, Pb, Cd, and Hg, metal "inhibition" of ferrochelatase is not due to the inability of the enzyme to insert the metal into the macrocycle or by binding to a second metal binding site as has been previously proposed. Rather, inhibition occurs after metal insertion and results from poor or diminished product release. Possible explanations for the lack of product release are proposed herein.
Product release rather than chelation determines metal specificity for ferrochelatase.,Medlock AE, Carter M, Dailey TA, Dailey HA, Lanzilotta WN J Mol Biol. 2009 Oct 23;393(2):308-19. Epub 2009 Aug 22. PMID:19703464[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Lamoril J, Boulechfar S, de Verneuil H, Grandchamp B, Nordmann Y, Deybach JC. Human erythropoietic protoporphyria: two point mutations in the ferrochelatase gene. Biochem Biophys Res Commun. 1991 Dec 16;181(2):594-9. PMID:1755842
↑Brenner DA, Didier JM, Frasier F, Christensen SR, Evans GA, Dailey HA. A molecular defect in human protoporphyria. Am J Hum Genet. 1992 Jun;50(6):1203-10. PMID:1376018
↑Sarkany RP, Alexander GJ, Cox TM. Recessive inheritance of erythropoietic protoporphyria with liver failure. Lancet. 1994 Jun 4;343(8910):1394-6. PMID:7910885
↑Imoto S, Tanizawa Y, Sato Y, Kaku K, Oka Y. A novel mutation in the ferrochelatase gene associated with erythropoietic protoporphyria. Br J Haematol. 1996 Jul;94(1):191-7. PMID:8757534
↑Rufenacht UB, Gouya L, Schneider-Yin X, Puy H, Schafer BW, Aquaron R, Nordmann Y, Minder EI, Deybach JC. Systematic analysis of molecular defects in the ferrochelatase gene from patients with erythropoietic protoporphyria. Am J Hum Genet. 1998 Jun;62(6):1341-52. PMID:9585598 doi:S0002-9297(07)62775-X
↑Gouya L, Schneider-Yin X, Rufenacht U, Herrero C, Lecha M, Mascaro JM, Puy H, Deybach JC, Minder EI. Mutations in the ferrochelatase gene of four Spanish patients with erythropoietic protoporphyria. J Invest Dermatol. 1998 Sep;111(3):406-9. PMID:9740232 doi:10.1046/j.1523-1747.1998.00327.x
↑Schneider-Yin X, Gouya L, Dorsey M, Rufenacht U, Deybach JC, Ferreira GC. Mutations in the iron-sulfur cluster ligands of the human ferrochelatase lead to erythropoietic protoporphyria. Blood. 2000 Aug 15;96(4):1545-9. PMID:10942404
↑Rufenacht UB, Gregor A, Gouya L, Tarczynska-Nosal S, Schneider-Yin X, Deybach JC. New missense mutation in the human ferrochelatase gene in a family with erythropoietic protoporphyria: functional studies and correlation of genotype and phenotype. Clin Chem. 2001 Jun;47(6):1112-3. PMID:11375302
↑Poh-Fitzpatrick MB, Wang X, Anderson KE, Bloomer JR, Bolwell B, Lichtin AE. Erythropoietic protoporphyria: altered phenotype after bone marrow transplantation for myelogenous leukemia in a patient heteroallelic for ferrochelatase gene mutations. J Am Acad Dermatol. 2002 Jun;46(6):861-6. PMID:12063482
↑Wiman A, Floderus Y, Harper P. Novel mutations and phenotypic effect of the splice site modulator IVS3-48C in nine Swedish families with erythropoietic protoporphyria. J Hum Genet. 2003;48(2):70-6. PMID:12601550 doi:10.1007/s100380300009
↑Whatley SD, Mason NG, Khan M, Zamiri M, Badminton MN, Missaoui WN, Dailey TA, Dailey HA, Douglas WS, Wainwright NJ, Elder GH. Autosomal recessive erythropoietic protoporphyria in the United Kingdom: prevalence and relationship to liver disease. J Med Genet. 2004 Aug;41(8):e105. PMID:15286165 doi:10.1136/jmg.2003.016121
↑Aurizi C, Schneider-Yin X, Sorge F, Macri A, Minder EI, Biolcati G. Heterogeneity of mutations in the ferrochelatase gene in Italian patients with erythropoietic protoporphyria. Mol Genet Metab. 2007 Apr;90(4):402-7. Epub 2006 Dec 29. PMID:17196862 doi:S1096-7192(06)00355-6
↑Medlock AE, Carter M, Dailey TA, Dailey HA, Lanzilotta WN. Product release rather than chelation determines metal specificity for ferrochelatase. J Mol Biol. 2009 Oct 23;393(2):308-19. Epub 2009 Aug 22. PMID:19703464 doi:10.1016/j.jmb.2009.08.042
