Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
Science Center for Future Foods, Ministry of Education, Jiangnan University, Wuxi 214122, China.
ACS Synth Biol. 2023 Mar 17;12(3):863-876. doi: 10.1021/acssynbio.2c00673. Epub 2023 Mar 3.
Terpenoids are the largest class of natural products, and their bioproduction by engineered cell factories receives high attention. However, excessive intracellular accumulation is one of the bottlenecks that limit the further improvement of the yield of terpenoid products. Therefore, it is important to mine exporters to achieve the secretory production of terpenoids. This study proposed a framework for the prediction and mining of terpenoid exporters in . Through the process of "mining-docking-construction-validation", we found that Pdr5 of ATP-binding cassette (ABC) transporters and Osh3 of oxysterol-binding homology (Osh) proteins can promote squalene efflux. Squalene secretion of the strain overexpressing Pdr5 and Osh3 increased to 141.1 times that of the control strain. Besides squalene, ABC exporters also can promote the secretion of β-carotene and retinal. Molecular dynamics simulation results revealed that before exporter conformations transitioned to the "outward-open" states, the substrates might have bound to the tunnels and prepared for rapid efflux. Overall, this study provides a terpenoid exporter prediction and mining framework that may be generally used to identify exporters of other terpenoids.
萜类化合物是最大的天然产物类别，通过工程细胞工厂进行生物生产受到高度关注。然而，细胞内的过度积累是限制萜类产物产量进一步提高的瓶颈之一。因此，挖掘外排蛋白以实现萜类化合物的分泌生产非常重要。本研究提出了一种萜类化合物外排蛋白预测和挖掘的框架。通过“挖掘-对接-构建-验证”的过程，我们发现 ATP 结合盒（ABC）转运蛋白的 Pdr5 和氧化固醇结合同源蛋白（Osh）的 Osh3 可以促进角鲨烯外排。过表达 Pdr5 和 Osh3 的菌株的角鲨烯分泌量增加到对照菌株的 141.1 倍。除了角鲨烯，ABC 外排蛋白还可以促进β-胡萝卜素和视黄醛的分泌。分子动力学模拟结果表明，在外排蛋白构象转变为“外向开放”状态之前，底物可能已经结合到隧道中，并为快速外排做好了准备。总的来说，本研究提供了一个萜类化合物外排蛋白预测和挖掘框架，可用于鉴定其他萜类化合物的外排蛋白。
