上海科技大学赵素文、天津大学张雁和A*STAR赵惠民团队合作取得最新进展。他们发现噬菌体基因组中二氨基嘌呤（Z）取代腺嘌呤的广泛途径。2021年4月30日出版的国际知名学术期刊《科学》杂志发表了这一成果。

他们报告了一种支持Z基因组合成的多酶系统。他们鉴定了数十种在全球范围内含有此类酶的噬菌体，并使用紫外和质谱联用技术进一步验证了其中一种噬菌体（不动杆菌噬菌体SH-Ab 15497）中的Z基因组。Z基因组赋予噬菌体逃避宿主限制性内切酶攻击的进化优势，其生物合成途径的表征使Z-DNA大规模生产，可用于多种应用。

据悉，DNA修饰的形式和功能各不相同，但通常不会改变Watson-Crick碱基配对。Z是一个例外，因为它可以完全取代腺嘌呤，并在蓝藻S-2L基因组DNA中与胸腺嘧啶形成三个氢键。但是，Z基因组的生物合成、普遍性和重要性仍待探索。

附：英文原文

Title: A widespread pathway for substitution of adenine by diaminopurine in phage genomes

Author: Yan Zhou, Xuexia Xu, Yifeng Wei, Yu Cheng, Yu Guo, Ivan Khudyakov, Fuli Liu, Ping He, Zhangyue Song, Zhi Li, Yan Gao, Ee Lui Ang, Huimin Zhao, Yan Zhang, Suwen Zhao

Issue&Volume: 2021/04/30

Abstract: DNA modifications vary in form and function but generally do not alter Watson-Crick base pairing. Diaminopurine (Z) is an exception because it completely replaces adenine and forms three hydrogen bonds with thymine in cyanophage S-2L genomic DNA. However, the biosynthesis, prevalence, and importance of Z genomes remain unexplored. Here, we report a multienzyme system that supports Z-genome synthesis. We identified dozens of globally widespread phages harboring such enzymes, and we further verified the Z genome in one of these phages, Acinetobacter phage SH-Ab 15497, by using liquid chromatography with ultraviolet and mass spectrometry. The Z genome endows phages with evolutionary advantages for evading the attack of host restriction enzymes, and the characterization of its biosynthetic pathway enables Z-DNA production on a large scale for a diverse range of applications.

DOI: 10.1126/science.abe4882

Source: https://science.sciencemag.org/content/372/6541/512