Bacterial iron detoxification at the molecular level.
Bacterial iron detoxification at the molecular level.
复制标题
DOI：
10.1074/jbc.rev120.007746
复制
发表时间：
2020-12-18
期刊：
影响因子：
--
通讯作者：
Le Brun NE
中科院分区：
文献类型：
--
作者：
Bradley JM;Svistunenko DA;Wilson MT;Hemmings AM;Moore GR;Le Brun NE
铁是一种必需的微量营养素，就细菌而言，铁的可获得性通常是一个生长限制因素。然而，细胞的正常功能需要对可螯合的“游离”铁的不稳定池进行严格调节。需要铁作为辅助因子的蛋白质的正确金属化要求存在这样一个容易获得的铁来源，但过度积累会导致氧化负担，如果不加以控制，将导致细胞死亡。铁的毒性源于其催化活性氧形成的潜力，活性氧除了对生物分子造成损害外，还可以导致活性氮的形成。为了避免铁介导的氧化应激，细菌利用铁依赖的全局调节剂来感知细胞的铁状态，并相应地调节参与铁的获取、储存和外排的蛋白质的表达。在这里，我们调查了目前对这些蛋白质的重要成员的结构和机制的理解。铁稳态机制细节的多样性反映了细菌所栖息的各种生态位所造成的不同营养压力。然而，在这篇综述中，我们试图强调不同细菌之间铁稳态的相似性，同时承认重要的差异。通过这种方式，我们希望说明细菌如何进化出共同的方法来克服铁的不溶性和潜在毒性的双重问题。
Iron is an essential micronutrient, and, in the case of bacteria, its availability is commonly a growth-limiting factor. However, correct functioning of cells requires that the labile pool of chelatable “free” iron be tightly regulated. Correct metalation of proteins requiring iron as a cofactor demands that such a readily accessible source of iron exist, but overaccumulation results in an oxidative burden that, if unchecked, would lead to cell death. The toxicity of iron stems from its potential to catalyze formation of reactive oxygen species that, in addition to causing damage to biological molecules, can also lead to the formation of reactive nitrogen species. To avoid iron-mediated oxidative stress, bacteria utilize iron-dependent global regulators to sense the iron status of the cell and regulate the expression of proteins involved in the acquisition, storage, and efflux of iron accordingly. Here, we survey the current understanding of the structure and mechanism of the important members of each of these classes of protein. Diversity in the details of iron homeostasis mechanisms reflect the differing nutritional stresses resulting from the wide variety of ecological niches that bacteria inhabit. However, in this review, we seek to highlight the similarities of iron homeostasis between different bacteria, while acknowledging important variations. In this way, we hope to illustrate how bacteria have evolved common approaches to overcome the dual problems of the insolubility and potential toxicity of iron.