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菌体编码的抗CRISPR可以完全逃避VI-A型的CRISPR-Cas免疫
Alexander J Meeske1, Ning Jia2, Alice K Cassel1
1Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA.
Science (New York, N.Y.)
|May 30, 2020
概括
病毒可以逃避CRISPR-Cas免疫力. 一种来自listeriaphage的新型抗CRISPR蛋白 (AcrVIA1) 禁用了Cas13a酶,完全阻断了RNA引导的细菌防御.
科学领域:
- 微生物学
- 分子生物学
- 生物化学
背景情况:
- 在细菌和古生物中,CRISPR-Cas系统提供了对外核酸的适应性免疫力.
- 第六类CRISPR-Cas系统,特别是Cas13,向和降解RNA分子,提供对RNA病毒和等离子体的防御.
- 病毒对抗VI型CRISPR-Cas免疫的机制在很大程度上仍未被探索.
研究的目的:
- 识别和描述对抗VI-A型CRISPR-Cas系统的病毒因素.
- 阐明一种特定的抗CRISPR蛋白抑制Cas13a活性的机制.
主要方法:
- 李斯特菌的基因分析 φLS46 和 *Listeria seeligeri* CRISPR-Cas 系统.
- 在AcrVIA1的存在下评估Cas13a核酶活性的生物化学测试.
- 结构生物学技术 (例如,X射线晶体) 来确定AcrVIA1和Cas13a之间的相互作用接口.
主要成果:
- 发现了AcrVIA1,一个由listeriaphage φLS46编码的抗CRISPR蛋白质,该蛋白质特别抑制*Listeria seeligeri*类型VI-ACRISPR-Cas系统.
- AcrVIA1与Cas13a的指导RNA结合面结合,从而阻碍了标RNA的识别和核酶的激活.
- 与向DNA的Cas核酶抑制剂不同的是,单个输送AcrVIA1的病毒足以完全消除VI-A型的CRISPR介导免疫力.
结论:
- 病毒已经发展出复杂的抗CRISPR机制来克服细菌的RNA向免疫力.
- AcrVIA1是一种强大的Cas13a抑制剂,为操纵CRISPR-Cas系统提供了一种新工具.
- 了解这些病毒对策对于开发有效的菌体疗法和涉及CRISPR-Cas技术的合成生物学应用至关重要.
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