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通过ATP和SAM的结合进行抗病毒III型CRISPR信号传递
Haotian Chi1, Ville Hoikkala1,2, Sabine Grüschow1
1Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, UK.
Nature
|October 18, 2023
概括
在 Bacteroides fragilis 中的 III-B CRISPR 系统使用 S- 腺胺-AMP (SAM-AMP) 来进行抗病毒防御,而不是循环胺酸盐. 这种新型的第二信使准了膜蛋白,
科学领域:
- 分子生物学
- 微生物学
- 免疫学
背景情况:
- Prokaryotic CRISPR 系统提供了对移动基因元素的适应性免疫力.
- 第三种CRISPR系统使用CRISPRRNA和Cas10来检测和消除外来核酸.
- 一些III型系统涉及非特征性蛋白质,如CorA和固酶,用于防御.
研究的目的:
- 研究来自Bacteroides fragilis的与CORA相关的III-B (Cmr) CRISPR系统的抗病毒防御机制.
- 阐明参与B. fragilis Cmr系统免疫反应的信号分子和效应器.
- 通过CRISPR系统生成的新型第二信使的特征.
主要方法:
- 在大肠杆菌中表达 B. fragilis Cmr CRISPR 系统.
- 在激活CRISPR系统时产生的信号分子的分析.
- 生成的分子与Cora效应器之间的相互作用的生物化学特征.
主要成果:
- B. fragilis Cmr 系统对大肠杆菌中的移动基因元素具有免疫力.
- 该系统通过将ATP与S-adenosyl methionine (SAM) 结合而产生S-adenosyl methionine-AMP (SAM-AMP),而不是循环甲酸.
- SAM-AMP与Cora效应器结合,可能破坏膜完整性并导致细胞休眠或死亡.
结论:
- SAM-AMP是一种涉及 prokaryotic 抗病毒信号的新型传递器.
- B. fragilis的Cmr系统代表了CRISPR免疫的独特机制.
- 通过特定的酶降解SAM-AMP,为免疫反应提供了潜在的"关闭开关".
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