The eunicellane diterpenoids are a unique family of natural products seen in marine organisms, plants, and bacteria. We used a series of biochemical, bioinformatics, and theoretical experiments to investigate the mechanism of the first diterpene synthase known to form the eunicellane skeleton. Deuterium labeling studies and quantum chemical calculations support that Bnd4, from Streptomyces sp. (CL12-4), forms the 6,10-bicyclic skeleton through a 1,10-cyclization, 1,3-hydride shift, and 1,14-cyclization cascade. Bnd4 also demonstrated sesquiterpene cyclase activity and the ability to prenylate small molecules. Bnd4 possesses a unique D⁹⁴NxxxD motif and mutation experiments confirmed an absolute requirement for D94 as well as E169.

中文翻译：

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细菌二萜合酶 Bnd4 形成 6,10-双环 Eunicellane 骨架的机理研究

eunicellane 二萜是在海洋生物、植物和细菌中发现的独特的天然产物家族。我们使用一系列生化、生物信息学和理论实验来研究已知形成单链烷骨架的第一个二萜合酶的机制。氘标记研究和量子化学计算支持来自链霉菌属的 Bnd4 。(CL12-4)，通过 1,10-环化、1,3-氢化物移位和 1,14-环化级联形成 6,10-双环骨架。Bnd4 还表现出倍半萜环化酶活性和异戊二烯化小分子的能力。Bnd4 拥有独特的 D ⁹⁴ NxxxD 基序，突变实验证实了对 D94 和 E169 的绝对要求。