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Updated: Jul 23, 2025

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一个短的阿尔戈纳特-TIR原生物免疫系统的激活机制
Dongchun Ni1, Xuhang Lu2, Henning Stahlberg1
1Laboratory of Biological Electron Microscopy, IPHYS, SB, EPFL, and Dept. Fundamental Microbiology, Faculty of Biology and Medicine, UNIL, Cubotron, Rt. de la Sorge, 1015 Lausanne, Switzerland.
Science advances
|July 19, 2023
概括
短 prokaryotic argonaute (SPARTA) 复合体通过感知外来DNA/RNA来保护细菌. 结构研究揭示了SPARTA如何激活,导致细胞死亡和宿主免疫力.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 免疫学 免疫学 免疫学
背景情况:
- Prokaryotic argonaute (pAgo) 和PAZ (APAZ) 的TIR-analog组成了SPARTA复合体,提供了 prokaryotic 免疫力.
- SPARTA通过一种失败的感染机制起作用,通过尼古丁胺氨酸二核酸 (氧化形式) (NAD) 枯竭导致宿主细胞死亡.
研究的目的:
- 为了阐明SPARTA复合体的激活机制.
- 提供详细的结构洞察力,了解SPARTA在 prokaryotic 防御中的功能.
主要方法:
- 通过X射线晶体学,确定了SPARTA在各种功能状态中的9个结构.
- 结构分析的重点是SPARTA单体,二聚体和四聚体与RNA/DNA复合体结合.
主要成果:
- 不活跃的SPARTA单体结合RNA/DNA复合体,通过Ago子单元协会形成对称二元体.
- 四聚体组合的启动导致TIR域灵活性和破坏对称的旋转,促进TIR寡合化.
- 这一过程形成了基质结合口袋,并激活了SPARTA的NADase活性.
结论:
- 这项研究揭示了SPARTA复合体的逐步激活机制.
- 结构数据提供了机械的洞察力,以了解短阿尔戈诺特系统如何赋予 prokaryotic 免疫力.
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