外膜蛋白的结构从大肠杆菌OmpX揭示了毒性的可能机制。
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沃格特J,舒尔茨通用电气
外膜蛋白的结构从大肠杆菌OmpX揭示了毒性的可能机制。
结构。1999年10月15日,7 (10):1301 - 9。
- PubMed ID
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10545325 (在PubMed]
- 文摘
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背景:积分外膜蛋白质X (OmpX)大肠杆菌属于一个家庭的高度保守的细菌蛋白质,促进细菌粘附和进入哺乳动物细胞。此外,这些蛋白质在人类补体系统抵抗攻击。这里我们提出的第一个晶体结构这个家族的一员。结果:大肠杆菌OmpX的晶体结构决定分辨率1.9使用多个同形替换。OmpX由一个eight-stranded反平行的all-next-neighborβ桶。芳香族氨基酸残基的结构显示了两个腰带的带极性的残留物,附着在膜内部。桶的核心由一个扩展的氢键网络的高度保守的残留物。OmpX因此就像一个逆胶束。显著提高晶体质量的结构解释了OmpX包含突变His100 - - > Asn,使x射线分析成为可能。两个绑定的协调球体铂离子。 CONCLUSIONS: The OmpX structure shows that within a family of virulence-related membrane proteins, the membrane-spanning part of the protein is much better conserved than the extracellular loops. Moreover, these loops form a protruding beta sheet, the edge of which presumably binds to external proteins. It is suggested that this type of binding promotes cell adhesion and invasion and helps defend against the complement system. Although OmpX has the same beta-sheet topology as the structurally related outer membrane protein A (OmpA), their barrels differ with respect to the shear numbers and internal hydrogen-bonding networks.