Magnetic Resonance Center, University of Florence, Via Luigi Sacconi 6, Sesto Fiorentino 50019, Italy.
Metallomics. 2018 Sep 19;10(9):1223-1231. doi: 10.1039/c8mt00146d.
Organisms from all kingdoms of life use iron-proteins in a multitude of functional processes. We applied a bioinformatics approach to investigate the human portfolio of iron-proteins. We separated iron-proteins based on the chemical nature of their metal-containing cofactors: individual iron ions, heme cofactors and iron-sulfur clusters. We found that about 2% of human genes encode an iron-protein. Of these, 35% are proteins binding individual iron ions, 48% are heme-binding proteins and 17% are iron-sulfur proteins. More than half of the human iron-proteins have a catalytic function. Indeed, we predict that 6.5% of all human enzymes are iron-dependent. This percentage is quite different for the various enzyme classes. Human oxidoreductases feature the largest fraction of iron-dependent family members (about 37%). The distribution of iron proteins in the various cellular compartments is uneven. In particular, the mitochondrion and the endoplasmic reticulum are enriched in iron-proteins with respect to the average content of the cell. Finally, we observed that genes encoding iron-proteins are more frequently associated to pathologies than the all other human genes on average. The present research provides an extensive overview of iron usage by the human proteome, and highlights several specific features of the physiological role of iron ions in human cells.
所有生命领域的生物在多种功能过程中都使用铁蛋白。我们应用生物信息学方法来研究人类的铁蛋白组。我们根据其含金属辅因子的化学性质将铁蛋白分离：单个铁离子、血红素辅因子和铁硫簇。我们发现，约 2%的人类基因编码铁蛋白。其中，35%是结合单个铁离子的蛋白质，48%是血红素结合蛋白，17%是铁硫蛋白。超过一半的人类铁蛋白具有催化功能。事实上，我们预测所有人类酶中有 6.5%是依赖铁的。这个百分比在不同的酶类之间有很大的不同。人类氧化还原酶中具有最大比例的依赖铁的家族成员（约 37%）。铁蛋白在各种细胞区室中的分布不均匀。特别是线粒体和内质网中含有比细胞平均含量更多的铁蛋白。最后，我们观察到编码铁蛋白的基因与其他人类基因相比平均更容易与疾病相关。本研究提供了人类蛋白质组中铁利用的广泛概述，并强调了铁离子在人类细胞中生理作用的几个具体特征。
