联结的LolCDE结构显示出一种常见的基质-LolE相互作用,指导细菌脂蛋白运输
Paul Szewczyk1, Nicholas P Greene1, Martyn F Symmons1
1Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom.
概括
洛尔系统将细菌脂蛋白运送到外膜. 低温EM结构揭示了LolCDE载体如何与脂蛋白相互作用,通过保存机制促进它们的基本输出.
科学领域:
- 细菌细胞外生物发生.
- 蛋白质运输机制 蛋白质运输机制
- 结构生物学是结构生物学.
背景情况:
- 细菌脂蛋白对格拉姆阴性外膜结构和功能至关重要.
- 洛尔系统对于细菌活力至关重要,它调解脂蛋白运输.
- 该ABC传送器LolCDE和陪伴者Lola是Lol系统的关键组成部分.
研究的目的:
- 阐明由LolCDE复合体运输脂蛋白的结构基础.
- 了解LolCDE如何与各种脂蛋白基质相互作用.
- 揭示了从内膜向外膜释放脂蛋白的机制.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定LolCDE的结构.
- 复杂的形成有三个不同的脂蛋白基质 (Lpp,Pal,LolB).
- 结构分析以确定保存的相互作用接口和构造变化.
主要成果:
- 获得了与Lpp,Pal和LolB复合的LolCDE的冷EM结构.
- 缺乏无序链接体的脂蛋白在运输中采用未折叠的N终端状态.
- 在LolE上的裂中发生了一种保守的,独立于序列的相互作用,促进了高效的出口.
- 提出了一种脂蛋白出口模型,该模型涉及180°旋转的乙链.
结论:
- 通过保存的相互作用机制,LolCDE有效地运输结构多样化的脂蛋白.
- 与LolE的相互作用作为一个枢纽点,使得LolA结合的链重新定位成为可能.
- 这项研究为细菌生理学和潜在的抗微生物药物标的基本过程提供了关键的见解.
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