Ferritins: furnishing proteins with iron.
Ferritins: furnishing proteins with iron.
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DOI：
10.1007/s00775-016-1336-0
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发表时间：
2016-03
期刊：
影响因子：
--
通讯作者：
Moore GR
中科院分区：
文献类型：
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作者：
Bradley JM;Le Brun NE;Moore GR
铁蛋白是铁氧化、储存和矿化蛋白的超家族，在动物、植物和微生物王国中发现。大多数铁蛋白由24个亚基组成，这些亚基单独折叠成4-α-螺旋束，并以高度对称的方式组装，以形成围绕中心空腔的近似球形蛋白质外壳，其中可以形成含铁矿物。通道通过涂层在亚基间的接触点，促进铁离子的通道和从中央腔，和intrasubunit催化位点，称为ferroxidase中心，驱动Fe 2+氧化和O2还原。虽然超家族的不同成员共享共同的结构，但它们之间的氨基酸序列通常很少相同。即使在两种铁蛋白之间存在高度序列同一性的情况下，蛋白质处理铁的方式也可能存在重大差异。在这篇综述中，我们描述了一些重要的铁蛋白及其矿化的铁核心的结构特征，考虑如何铁可能被释放的铁蛋白，并详细研究如何选择三个铁蛋白氧化Fe 2+，探讨铁蛋白之间存在的机械变化。我们认为，机制的差异反映了不同的氨基酸序列上的进化压力，这些不同的压力是不同的铁蛋白的不同的主要功能的结果。
Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores, consider how iron might be released from ferritins, and examine in detail how three selected ferritins oxidise Fe2+ to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins.