Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States.
Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32827, United States.
Arch Biochem Biophys. 2021 Jul 15;705:108917. doi: 10.1016/j.abb.2021.108917. Epub 2021 May 12.
Oxo-bridged diiron proteins are a distinct class of non-heme iron proteins. Their active sites are composed of two irons that are coordinated by amino acid side chains, and a bridging oxygen that interacts with each iron. These proteins are members of the ferritin superfamily and share the structural feature of a four α-helix bundle that provides the residues that coordinate the irons. The different proteins also display a wide range of structures and functions. A prototype of this family is hemerythrin, which functions as an oxygen transporter. Several other hemerythrin-like proteins have been described with a diversity of functions including oxygen and iron sensing, and catalytic activities. Rubrerythrins react with hydrogen peroxide and rubrerythrin-like proteins possess a rubredoxin domain, in addition to the oxo-bridged diiron center. Other redox enzymes with oxo-bridged irons include flavodiiron proteins that act as O or NO reductases, ribonucleotide reductase and methane monooxygenase. Ferritins have an oxo-bridged diiron in the ferroxidase center of the protein, which plays a role in the iron storage function of these proteins. There are also bacterial ferritins that exhibit catalytic activities. The structures and functions of this broad class of oxo-bridged diiron proteins are described and compared in this review.
氧桥双核铁蛋白是一类独特的非血红素铁蛋白。它们的活性部位由两个铁原子组成，由氨基酸侧链配位，一个桥接氧原子与每个铁原子相互作用。这些蛋白是铁蛋白超家族的成员，具有由四个α-螺旋束组成的结构特征，为配位铁原子提供残基。不同的蛋白质也显示出广泛的结构和功能。该家族的原型是血蓝蛋白，它作为氧气转运蛋白发挥作用。已经描述了几种其他类似血蓝蛋白的蛋白，具有多种功能，包括氧气和铁感应以及催化活性。Rubrerythrins 与过氧化氢反应，Rubrerythrins 样蛋白除了具有氧桥双核铁中心外，还具有 rubredoxin 结构域。其他具有氧桥铁的氧化还原酶包括作为 O 或 NO 还原酶的黄素铁蛋白、核苷酸还原酶和甲烷单加氧酶。铁蛋白在蛋白的亚铁氧化酶中心具有氧桥双核铁，在这些蛋白的铁储存功能中起作用。还有具有催化活性的细菌铁蛋白。本文综述了这一大类氧桥双核铁蛋白的结构和功能，并对其进行了比较。
