三种小伙伴蛋白促进抗菌核酶的依赖于第七种类型的分泌出口
Yaping Yang1, Eleanor Boardman1, Justin Deme2
1Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
bioRxiv : the preprint server for biology
|July 18, 2023
概括
黄金葡萄球菌的 VIIb 型蛋白质分泌系统 (T7SSb) 使用 EsxBCD 蛋白质输出有毒核酶 EsaD. 结构研究揭示了EsxBCD结合如何为有效的毒素出口创造特定的形状.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 类型VIIb蛋白质分泌系统 (T7SSb) 对于细菌之间的竞争至关重要,它分泌有毒的效应蛋白.
- T7SSb基因的精确分泌机制和功能在很大程度上仍未被阐明.
- EsaD是通过T7SSb分泌的金黄色葡萄球菌的核酶毒素,与免疫蛋白EsaG和伴侣EsaE形成复合体.
研究的目的:
- 研究EsxB,EsxC和EsxD蛋白在EsaD分泌中的作用.
- 为了确定T7SSb基质前分泌复合物的结构基础.
主要方法:
- 使用冷电子显微镜 (Cryo-EM) 确定了 EsaDEG 三分机和 EsaDEG-EsxBCD 六分机的结构.
- 进行了生物化学测试,以分析EsaD和EsxBCD之间的相互作用.
主要成果:
- EsxBCD蛋白与EsaD的运输领域结合,作为重要的出口因素.
- 纳入EsxBCD导致了预分泌复合体的特定形状,具有灵活的货物领域和狭窄的轴.
- 这种形状被认为对EsaD的有效出口至关重要.
结论:
- EsxBCD是通过T7SSb促进核酶毒素EsaD出口的关键组件.
- 确定的结构为T7SSb系统的蛋白质出口机制提供了新的见解.
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