Microbial iron transport via a siderophore shuttle: A membrane ion transport paradigm
Microbial iron transport via a siderophore shuttle: A membrane ion transport paradigm
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DOI：
10.1073/pnas.200318797
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发表时间：
2000-09-26
影响因子：
11.1
通讯作者：
Raymond, KN
中科院分区：
文献类型：
--
作者：
Stintzi, A;Barnes, C;Raymond, KN
报道了离子跨膜迁移的机理。Fe 3+的微生物运输通常提供铁，一种限制生长的营养素。通过高度特异性的铁载体介导的运输系统进入细胞。与此相反，铁运输在淡水细菌气单胞菌被发现发生通过一个不加区别的铁载体运输系统组成的一个单一的多功能受体。结果表明：（1）铁载体和Fe ~（3+）一起进入细菌。(ii)在转运过程中发生配体交换步骤，和（iii）铁交换中不涉及氧化还原过程。据我们所知，还没有其他的报告，在细菌铁转运的配体交换机制。配体交换步骤发生在细胞表面，涉及铁从含铁铁载体交换到已经与受体结合的不含铁的铁载体。这种配体交换机制也存在于大肠杆菌中，似乎很可能广泛分布于微生物中。
A mechanism of ion transport across membranes is reported. Microbial transport of Fe3+ generally delivers iron, a growth-limiting nutrient. to cells via highly specific siderophore-mediated transport systems. In contrast, iron transport in the fresh water bacterium Aeromonas hydrophila is found to occur by means of an indiscriminant siderophore transport system composed of a single multifunctional receptor. It is shown that (i) the siderophore and Fe3+ enter the bacterium together. (ii) a ligand exchange step occurs in the course of the transport, and (iii) a redox process is not involved in iron exchange. To the best of our knowledge, there have been no other reports of a ligand exchange mechanism in bacterial iron transport. The ligand exchange step occurs at the cell surface and involves the exchange of iron from a ferric siderophore to an iron-free siderophore already bound to the receptor. This ligand exchange mechanism is also found in Escherichia coli and seems likely to be widely distributed among microorganisms.