GSDMB孔隙形成的结构基础及其IpaH7.8的向
Chengliang Wang1, Sonia Shivcharan1, Tian Tian1
1Department of Immunology, School of Medicine, University of Connecticut Health Center, Farmington, CT, USA.
Nature
|March 29, 2023
概括
西格拉
科学领域:
- 分子生物学
- 免疫学
- 结构生物学
背景情况:
- 气体皮质蛋白 (GSDM) 是形成孔隙的蛋白质,对于宿主防御机制热亡至关重要.
- 虽然它具有直接的杀菌活性,但GSDMB的独特特性和火性潜力仍在争论中.
- 石格拉通过IpaH7.8效应器逃避GSDMB介导的防御,该效应器针对GSDMB进行降解.
研究的目的:
- 阐明Shigella IpaH7.8的结构基础,识别和准GSDMB.
- 调查GSDMB孔隙形成和热活动的结构调节.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定GSDMB-IpaH7.8复合体和GSDMB孔的结构.
- 结构分析确定了与蛋白质相互作用和调节有关的关键残留物和动机.
主要成果:
- 冷-EM结构显示了Shigella IpaH7.8识别的GSDMB中的三个负电荷残留物,解释了物种特异性.
- GSDMB 孔隙结构突出了替代拼接调节的域间链接器在调节热活动中的作用.
- 具有正规链接剂的GSDMB异型显示正常的热,而其他异型则有减弱或没有活性.
结论:
- 这项研究揭示了Shigella IpaH7.8针对GSDMB的分子机制.
- 在GSDMB中,特定的结构图案对IpaH7.8的识别至关重要,并决定了物种特异性.
- GSDMB域间链接器的替代拼接显著影响其热功能.
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