Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, 100081 Beijing, China.
Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology - ABBt, RWTH Aachen University Worringer Weg 1, 52074 Aachen, Germany.
ACS Synth Biol. 2022 Aug 19;11(8):2685-2696. doi: 10.1021/acssynbio.2c00098. Epub 2022 Aug 3.
Triterpenoids are a subgroup of terpenoids and have wide applications in the food, cosmetics, and pharmaceutical industries. The heterologous production of various triterpenoids in , as well as other microbes, has been successfully implemented as these production hosts not only produce the precursor of triterpenoids 2,3-oxidosqualene by the mevalonate pathway but also allow simple expression of plant membrane-anchored enzymes. Nevertheless, 2,3-oxidosqualene is natively converted to lanosterol catalyzed by the endogenous lanosterol synthase (Erg7p), causing low production of recombinant triterpenoids. While simple deletion of was not effective, in this study, the critical amino acid residues of Erg7p were engineered to lower this critical enzyme activity. The engineered indeed accumulated 2,3-oxidosqualene up to 180 mg/L. Engineering triterpenoid synthesis into the -modified strain resulted in 7.3- and 3-fold increases in the titers of dammarane-type and lupane-type triterpenoids, respectively. This study presents an efficient inducer-free strategy for lowering Erg7p activity, thereby providing 2,3-oxidosqualene for the enhanced production of various triterpenoids.
三萜类化合物是萜类化合物的一个亚组，在食品、化妆品和制药行业有广泛的应用。各种三萜类化合物在酵母和其他微生物中的异源生产已经成功实施，因为这些生产宿主不仅通过甲羟戊酸途径产生三萜类化合物的前体 2,3-氧化鲨烯，而且还允许植物膜锚定酶的简单表达。然而，2,3-氧化鲨烯天然地被内源性羊毛甾醇合酶（Erg7p）催化转化为羊毛甾醇，导致重组三萜类化合物的产量较低。虽然简单地删除并不有效，但在本研究中，对 Erg7p 的关键氨基酸残基进行了工程改造，以降低该关键酶的活性。工程化的 Erg7p 确实积累了高达 180mg/L 的 2,3-氧化鲨烯。将三萜类化合物的合成工程化到 -修饰的菌株中，导致达玛烷型和羽扇豆烷型三萜类化合物的产量分别增加了 7.3 倍和 3 倍。本研究提出了一种有效的无诱导剂策略来降低 Erg7p 的活性，从而为各种三萜类化合物的增强生产提供 2,3-氧化鲨烯。
