Extracellular heme uptake and the challenges of bacterial cell membranes.
Extracellular heme uptake and the challenges of bacterial cell membranes.
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DOI：
10.1016/b978-0-12-394390-3.00013-6
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发表时间：
2012
影响因子：
--
通讯作者：
Wilks, Angela
中科院分区：
文献类型：
--
作者：
Smith, Aaron D.;Wilks, Angela
在细菌中，保持足够的铁水平和防止过量铁的有害影响之间的微妙平衡导致了获取、储存和调节铁的复杂细胞机制的进化。鉴于铁的生物利用度有限并且需要穿过细菌细胞壁和细胞膜，铁的吸收提出了重大挑战。病原菌利用宿主的含血红素蛋白质作为铁源，从而规避了铁可用性问题。一旦被内化，铁就会通过酶促作用从卟啉中释放出来，用于细菌细胞内的细胞过程。血红素是一种亲脂性有毒分子，由于其化学反应性，在运输方面提出了重大挑战。因此，病原菌已经进化出复杂的膜转运蛋白来协调、隔离和运输血红素。在配体协调、蛋白质-蛋白质相互作用和血红素转移的背景下讨论了膜结合血红素转运蛋白的生化和结构表征的最新进展。
In bacteria, the fine balance of maintaining adequate iron levels while preventing the deleterious effects of excess iron has led to the evolution of sophisticated cellular mechanisms to obtain, store, and regulate iron. Iron uptake provides a significant challenge given its limited bioavailability and need to be transported across the bacterial cell wall and membranes. Pathogenic bacteria have circumvented the iron-availability issue by utilizing the hosts' heme-containing proteins as a source of iron. Once internalized, iron is liberated from the porphyrin enzymatically for cellular processes within the bacterial cell. Heme, a lipophilic and toxic molecule, poses a significant challenge in terms of transport given its chemical reactivity. As such, pathogenic bacteria have evolved sophisticated membrane transporters to coordinate, sequester, and transport heme. Recent advances in the biochemical and structural characterization of the membrane-bound heme transport proteins are discussed in the context of ligand coordination, protein–protein interaction, and heme transfer.