Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University) , Ministry of Education and Wuhan University School of Pharmaceutical Sciences , Wuhan 430071 , People's Republic of China.
ACS Chem Biol. 2018 Aug 17;13(8):2203-2210. doi: 10.1021/acschembio.8b00375. Epub 2018 Jun 19.
Hygromycin B is an aminoglycoside antibiotic with a structurally distinctive orthoester linkage. Despite its long history of use in industry and in the laboratory, its biosynthesis remains poorly understood. We show here, by in-frame gene deletion in vivo and detailed enzyme characterization in vitro, that formation of the unique orthoester moiety is catalyzed by the α-ketoglutarate- and non-heme iron-dependent oxygenase HygX. In addition, we identify HygF as a glycosyltransferase adding UDP-hexose to 2-deoxystreptamine, HygM as a methyltransferase responsible for N-3 methylation, and HygK as an epimerase. These experimental results and bioinformatic analyses allow a detailed pathway for hygromycin B biosynthesis to be proposed, including the key oxidative cyclization reactions.
潮霉素 B 是一种氨基糖苷类抗生素，具有结构独特的邻酯键。尽管它在工业和实验室中的应用历史悠久，但它的生物合成仍知之甚少。我们在这里通过体内的框内基因缺失和体外的详细酶特性分析表明，独特的邻酯部分的形成是由α-酮戊二酸和非血红素铁依赖性加氧酶 HygX 催化的。此外，我们还鉴定出 HygF 是一种将 UDP-己糖添加到 2-脱氧链霉胺上的糖基转移酶，HygM 是负责 N-3 甲基化的甲基转移酶，HygK 是差向异构酶。这些实验结果和生物信息学分析允许提出潮霉素 B 生物合成的详细途径，包括关键的氧化环化反应。
