Iron Transport and Metabolism in Escherichia, Shigella, and Salmonella.
Iron Transport and Metabolism in Escherichia, Shigella, and Salmonella.
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DOI：
10.1128/ecosalplus.esp-0034-2020
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发表时间：
2021-12-15
期刊：
影响因子：
--
通讯作者：
Payne SM
中科院分区：
文献类型：
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作者：
Mey AR;Gómez-Garzón C;Payne SM
铁是大肠杆菌、沙门氏菌和志贺氏菌的必需元素。在许多环境中，包括这些细菌通常居住的肠道，获得足够量的铁是困难的。这些属的成员有多个铁运输系统来运输亚铁和三价铁。这些包括游离亚铁、螯合剂相关三价铁和血红素的转运蛋白。任何物种的运输系统的数量和类型都反映了它所能栖息的生态位的多样性。许多铁转运基因被发现在移动的遗传元件或致病岛上，并且有证据表明这些基因在不同物种和致病型之间传播。这在通过水平基因转移获得的铁转运系统允许细菌克服宿主先天防御的属的致病成员中是值得注意的，所述宿主先天防御用于限制病原体对铁的可用性。对铁的需求与避免铁过载的需求相平衡，因为过量的铁对细胞有毒。铁运输和代谢的基因受到严格的调控，并对环境因素（包括铁的可用性、氧气和温度）做出反应。主调节器，铁传感器Fur和Fur调节的sRNA RyhB，协调铁转运和细胞代谢基因的表达，以响应铁的可用性。
Iron is an essential element for Escherichia, Salmonella and Shigella species. Acquisition of sufficient amounts of iron is difficult in many environments, including the intestinal tract, where these bacteria usually reside. Members of these genera have multiple iron transport systems to transport both ferrous and ferric iron. These include transporters for free ferrous iron, for ferric iron associated with chelators, and heme. The number and types of transport systems in any species reflects the diversity of niches it can inhabit. Many of the iron transport genes are found on mobile genetic elements or pathogenicity islands, and there is evidence of spread of the genes among different species and pathotypes. This is notable among the pathogenic members of the genera in which iron transport systems acquired by horizontal gene transfer allow the bacteria to overcome host innate defenses that act to restrict the availability of iron to the pathogen. The need for iron is balanced by the need to avoid iron overload, since excess iron is toxic for the cell. Genes for iron transport and metabolism are tightly regulated and respond to environmental cues including iron availability, oxygen and temperature. The master regulators, the iron sensor Fur and the Fur-regulated sRNA RyhB, coordinate expression of iron transport and cellular metabolism genes in response to the availability of iron.