Wax esters (WE) belong to the class of neutral lipids. They are formed by an esterification of a fatty alcohol and an activated fatty acid. Dependent on the chain length and desaturation degree of the fatty acid and the fatty alcohol moiety, WE can have diverse physicochemical properties. WE derived from monounsaturated long‐chain acyl moieties are of industrial interest due to their very good lubrication properties. Whereas WE were obtained in the past from spermaceti organs of the sperm whale, industrial WE are nowadays mostly produced chemically from fossil fuels. In order to produce WE more sustainably, attempts to produce industrial WE in transgenic plants are steadily increasing. To achieve this, different combinations of WE producing enzymes are expressed in developing Arabidopsis thaliana or Camelina sativa seeds. Here we report the identification and characterization of a fifth wax synthase from the organism Marinobacter aquaeolei VT8, MaWSD5. It belongs to the class of bifunctional wax synthase/acyl‐CoA:diacylglycerol O‐acyltransferases (WSD). The protein was purified to homogeneity. In vivo and in vitro substrate analyses revealed that MaWSD5 is able to synthesize WE but no triacylglycerols. The protein produces WE from saturated and monounsaturated mid‐ and long‐chain substrates. Arabidopsis thaliana seeds expressing a fatty acid reductase from Marinobacter aquaeolei VT8 and MaWSD5 produce WE. Main WE synthesized are 20:1/18:1 and 20:1/20:1. This makes MaWSD5 a suitable candidate for industrial WE production in planta.

中文翻译：

---

海洋水杆菌 VT8 的第五个 WS/DGAT 酶。

蜡酯 (WE) 属于中性脂质类。它们是通过脂肪醇和活化脂肪酸的酯化作用形成的。根据脂肪酸和脂肪醇部分的链长和去饱和度，WE 可以具有不同的理化性质。源自单不饱和长链酰基部分的 WE 由于其非常好的润滑性能而具有工业意义。过去 WE 是从抹香鲸的鲸类器官中获得的，而现在工业 WE 主要是从化石燃料中化学生产的。为了更可持续地生产 WE，在转基因植物中生产工业 WE 的尝试正在稳步增加。为了实现这一目标，在拟南芥或拟南芥中表达了不同的 WE 产生酶组合亚麻荠种子。在这里，我们报告了来自生物体Marinobacter aquaeoolei VT8、MaWSD5的第五种蜡合酶的鉴定和表征。它属于双功能蜡合酶/酰基辅酶A：二酰基甘油O-酰基转移酶（WSD）。将蛋白质纯化至均一。体内和体外底物分析表明，MaWSD5 能够合成 WE，但不能合成三酰甘油。该蛋白质从饱和和单不饱和的中链和长链底物产生 WE。拟南芥种子表达来自Marinobacter aquaolei的脂肪酸还原酶VT8 和 MaWSD5 产生 WE。主要合成的 WE 是 20:1/18:1 和 20:1/20:1。这使得 MaWSD5 成为植物中工业 WE 生产的合适候选者。