细菌铁(Ⅲ)结合蛋白:结构与机理(英文)

铁是生命体必需的微量元素,在大多数环境中铁是有限的资源.高效摄取铁是入侵属主的微生物生存和毒力的关键.许多致病细菌进化出一个特异的铁吸收系统,利用特定的外膜受体和周质铁离子结合蛋白(FBP或FbpA)从属主偷取铁离子.FBP在高效摄取铁的过程中,无论从自由铁源摄取铁或从属主体内转铁蛋白和乳铁蛋白摄取结合的铁,都起着至关重要的作用.FBP的铁结合机制在不同物种间高度保守.结构数据显示,FBP的三维折叠类似于哺乳动物转铁蛋白(TF)的一叶,铁(Ⅲ)在FBP的两个结构域之间的间隙结合但其铁结合位点较其在转铁蛋白中更暴露于溶剂.该小综述总结了FBP铁转运系统,主要讨论了铁结合蛋白的结构和配位化学特征以及铁转运及调控机理.

Bacterial Ferric-ion Binding Proteins:Structures and Mechanisms

Iron is an essential and a limiting resource in most environments.Efficient iron acquisition is critical for invading microbe ’ s survival and virulence.Numerous pathogenic bacteria have evolved a specific iron uptake system,using specific outer membrane receptors and a periplasmic ferric ion-binding protein(FBP or FbpA) to steal iron from the host.FBP plays a crucial role in the high-affinity iron uptake from both free iron sources and iron bound by transferrin and lactoferrin within the host.The mechanism of iron binding by FBP appears to be highly conserved between different species.Structural data on FBP ’ s reveal that the 3D-fold resembles that of each lobe of mammalian transferrin(Tf),with Fe(Ⅲ) bound in a cleft between the two domains,although the iron site in FBP is much more solvent-exposed.This minireview discusses the FBP iron transport system,with special focus on the iron coordination,protein structures and mechanisms underlying iron transport.