深海稀有放线菌抗肿瘤假诺卡菌素A 1,8二氮杂蒽母核生物合成机制研究

假诺卡菌素A是本学科组从一株深海稀有放线菌新物种Pseudonocardia antitumoralis sp. Nov分离的新天然产物，含有独特的1,8-二氮杂蒽母核，抗肿瘤活性显著，对于抗肿瘤药物研发具有重要意义。至今1,8-二氮杂蒽母核类天然产物的生物合成基因簇尚未发现，限制了其生物合成深入开展。本项目拟对假诺卡菌素A及同具有1,8-二氮杂蒽母核的尼博霉素生产菌，分别全基因测序和构建全基因组文库。通过比较基因组学，预测1,8-二氮杂蒽母核生物合成基因簇。利用基因敲除或回补技术，鉴定生物合成基因体内功能；对于关键生物合成基因进行异源表达及蛋白纯化，揭示其体外酶学功能，阐释1,8-二氮杂蒽母核的生物合成机制。运用组合生物合成，为理性创制“非天然”1,8-二氮杂蒽类天然产物，提供行之有效的蓝图。

Pseudonocardian A, a new natural product with unique 1,8-Diazaanthracene core structure, was isolated from deep-sea rare actinomycete Pseudonocardia antitumoralis sp. nov in our group. This compound exhibited striking antitumor activity. As far as we know, not any biosynthetic gene cluster for the compound with 1,8-Diazaanthracene core structure has been reported. In this project, comparative genomics is exploited for the discovery of putative gene cluster for biosynthesis of 1,8-Diazaanthracene core structure. Gene deletion and complementation analysis are used to identify the in vivo functions of genes involved in 1,8-Diazaanthracene biosynthesis. The key biosynthetic genes will be heterologously expressed and purified for the in vitro functional characterization of the enzyme. The biosynthetic pathway of 1,8-Diazaanthracene core structure will be proposed. This project will provide the feasible strategy for rational generation of non-natural compounds with 1,8-Diazaanthracene core structure by combinatorial biosynthesis.