In defense of phage: viral suppressors of CRISPR-mediated adaptive immunity in bacteria.
In defense of phage: viral suppressors of CRISPR-mediated adaptive immunity in bacteria.
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DOI：
10.4161/rna.23591
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发表时间：
2013-05
期刊：
影响因子：
4.1
通讯作者：
Wiedenheft B
中科院分区：
文献类型：
--
作者：
Wiedenheft B
感染细菌的病毒是地球上最丰富的生物制剂，细菌已经进化出多种防御机制来对抗这些遗传寄生虫。其中一种细菌防御系统依赖于一种重复位点，称为CRISPR（有规则间隔的短回文重复序列簇）。细菌和古细菌通过在CRISPR位点的一端整合外源核酸的短片段获得对入侵病毒和质粒的抵抗力。CRISPR基因座被转录，长长的初级CRISPR转录物被加工成一个小rna文库，引导免疫系统入侵核酸，随后被专用核酸酶降解。然而，crispr介导的免疫系统的发展并没有根除噬菌体，这表明病毒已经进化出破坏crispr介导的保护机制。最近，Bondy-Denomy及其同事发现了几种噬菌体编码的抗crispr蛋白，这些蛋白为病毒寄生虫与其宿主免疫系统之间正在进行的分子军备竞赛提供了新的见解。
Viruses that infect bacteria are the most abundant biological agents on the planet and bacteria have evolved diverse defense mechanisms to combat these genetic parasites. One of these bacterial defense systems relies on a repetitive locus, referred to as a CRISPR (clusters of regularly interspaced short palindromic repeats). Bacteria and archaea acquire resistance to invading viruses and plasmids by integrating short fragments of foreign nucleic acids at one end of the CRISPR locus. CRISPR loci are transcribed and the long primary CRISPR transcript is processed into a library of small RNAs that guide the immune system to invading nucleic acids, which are subsequently degraded by dedicated nucleases. However, the development of CRISPR-mediated immune systems has not eradicated phages, suggesting that viruses have evolved mechanisms to subvert CRISPR-mediated protection. Recently, Bondy-Denomy and colleagues discovered several phage-encoded anti-CRISPR proteins that offer new insight into the ongoing molecular arms race between viral parasites and the immune systems of their hosts.