美国麻省理工学院张锋实验室发现多种酶活性参与介导原核生物的抗病毒免疫。相关论文发表在2020年8月28日出版的《科学》杂志上。

通过系统的防御基因预测和异源重组，研究人员发现了29种广泛的抗病毒基因盒，其共同存在于32％的所有已测序细菌和古细菌基因组中，它们介导了针对特定噬菌体的保护。这些系统结合了以往未知的抗病毒防御酶活，包括RNA编辑和卫星DNA合成逆转录。此外，研究人员通过计算预测了仍有待鉴定的其他潜在防御基因。这些结果突出了微生物用来抵御病毒的大量分子功能。

据介绍，细菌和古细菌经常受到病毒和其他移动遗传元件的攻击，并依靠专用的抗病毒防御系统（如限制性内切核酸酶和CRISPR）来生存。病毒种类繁多，这表明防御系统的类型比目前已知的要多。 

附：英文原文

Title: Diverse enzymatic activities mediate antiviral immunity in prokaryotes

Author: Linyi Gao, Han Altae-Tran, Francisca Bhning, Kira S. Makarova, Michael Segel, Jonathan L. Schmid-Burgk, Jeremy Koob, Yuri I. Wolf, Eugene V. Koonin, Feng Zhang

Issue&Volume: 2020/08/28

Abstract: Bacteria and archaea are frequently attacked by viruses and other mobile genetic elements and rely on dedicated antiviral defense systems, such as restriction endonucleases and CRISPR, to survive. The enormous diversity of viruses suggests that more types of defense systems exist than are currently known. By systematic defense gene prediction and heterologous reconstitution, here we discover 29 widespread antiviral gene cassettes, collectively present in 32% of all sequenced bacterial and archaeal genomes, that mediate protection against specific bacteriophages. These systems incorporate enzymatic activities not previously implicated in antiviral defense, including RNA editing and retron satellite DNA synthesis. In addition, we computationally predict a diverse set of other putative defense genes that remain to be characterized. These results highlight an immense array of molecular functions that microbes use against viruses.

DOI: 10.1126/science.aba0372

Source: https://science.sciencemag.org/content/369/6507/1077