Structural basis of CRISPR-Cas Type III prokaryotic defence systems
Structural basis of CRISPR-Cas Type III prokaryotic defence systems
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DOI：
10.1016/j.sbi.2020.06.010
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发表时间：
2020-12-01
影响因子：
6.8
通讯作者：
Montoya, Guillermo
中科院分区：
文献类型：
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作者：
Molina, Rafael;Sofos, Nicholas;Montoya, Guillermo
CRISPR基因座和CRISPR相关（Cas）基因编码一种适应性免疫系统，保护许多细菌和几乎所有的古细菌免受来自噬菌体和质粒的侵入性遗传因子的侵害。几种类型的CRISPR系统已经被表征，其中III型CRISPR系统表现出最独特的功能。III型成员不仅通过相应的效应复合体切割RNA和DNA，还通过这些效应复合体产生的第二信使激活的CRISPR-Cas相关蛋白切割RNA和DNA。此外，最近发现的称为环核酸酶的第二信使降解蛋白增加了一个额外的调节层来微调这些免疫系统。在这里，我们回顾了控制III型CRISPR干扰免疫系统的防御机制，重点关注可用的结构信息。
CRISPR loci and CRISPR-associated (Cas) genes encode an adaptive immune system that protects many bacterial and almost all archaea against invasive genetic elements from bacteriophages and plasmids. Several classes of CRISPR systems have been characterized, of which the type III CRISPR systems exhibit the most unique functions. Members of type III cleave both RNA and DNA not only through their corresponding effector complexes but also by CRISPR-Cas associated proteins activated by second messengers produced by those effector complexes. Furthermore, the recent discovery of second messenger degrading proteins called ring nucleases adds an extra regulatory layer to fine-tune these immunity systems. Here, we review the defense mechanisms that govern type III CRISPR interference immunity systems focusing on the structural information available.