Hunter Gregory A, Al-Karadaghi Salam, Ferreira Gloria C
Department of Molecular Medicine, College of Medicine, University of South Florida, Tampa, Florida, 33620.
J Porphyr Phthalocyanines. 2011;15(5-6):350-356. doi: 10.1142/S108842461100332X.
Ferrochelatase (also known as PPIX ferrochelatase; Enzyme Commission number 4.9.9.1.1) catalyzes the insertion of ferrous iron into PPIX to form heme. This reaction unites the biochemically synchronized pathways of porphyrin synthesis and iron transport in nearly all living organisms. The ferrochelatases are an evolutionarily diverse family of enzymes with no more than six active site residues known to be perfectly conserved. The availability of over thirty different crystal structures, including many with bound metal ions or porphyrins, has added tremendously to our understanding of ferrochelatase structure and function. It is generally believed that ferrous iron is directly channeled to ferrochelatase in vivo, but the identity of the suspected chaperone remains uncertain despite much recent progress in this area. Identification of a conserved metal ion binding site at the base of the active site cleft may be an important clue as to how ferrochelatases acquire iron, and catalyze desolvation during transport to the catalytic site to complete heme synthesis.
亚铁螯合酶（也称为原卟啉IX亚铁螯合酶；酶学委员会编号4.9.9.1.1）催化亚铁插入原卟啉IX以形成血红素。该反应将几乎所有生物体中卟啉合成和铁运输的生物化学同步途径结合在一起。亚铁螯合酶是一个在进化上具有多样性的酶家族，已知只有不超过六个活性位点残基是完全保守的。三十多种不同晶体结构的可得性，包括许多带有结合金属离子或卟啉的结构，极大地增进了我们对亚铁螯合酶结构和功能的理解。一般认为亚铁在体内直接被输送到亚铁螯合酶，但尽管该领域最近取得了很大进展，疑似伴侣蛋白的身份仍不确定。在活性位点裂隙底部鉴定出一个保守的金属离子结合位点，可能是关于亚铁螯合酶如何获取铁以及在运输到催化位点以完成血红素合成过程中催化去溶剂化的重要线索。
