Key Laboratory of Chinese Medicinal Resource from Lingnan (Ministry of Education), School of Pharmaceutical Science, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
Hunan Provincial Key Laboratory for Synthetic Biology of Traditional Chinese Medicine, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua 418000, China.
J Agric Food Chem. 2024 Jun 12;72(23):13250-13261. doi: 10.1021/acs.jafc.4c02915. Epub 2024 May 30.
In plant secondary metabolite biosynthesis, acylation is a diverse physiological process, with BAHD acyltransferases playing an essential role. Borneol acetyltransferase (BAT) is an alcohol acetyltransferase, which catalyzes borneol and acetyl-CoA to synthesize bornyl acetate (BA). However, the enzymes involved in the biosynthesis of BA have so far only been characterized in , the studies on the WvBATs have only been conducted , and the catalytic activity was relatively low. In this research, three genes (, , and ) have been identified to encode BATs that are capable of acetylating borneol to synthesize BA . We also determined that WlBAT1 has the highest catalytic efficiency for borneol-type substrates, including (+)-borneol, (-)-borneol, and isoborneol. Furthermore, we found that BATs could catalyze a wide range of substrate types , but , they exclusively catalyzed borneol-type substrates. Through molecular simulations and site-directed mutagenesis, it was revealed that residues D32, N36, H168, N297, N355, and H384 are crucial for the catalytic activity of WlBAT1, while the R382I-D385R double mutant of WlBAT1 exhibited an increasing acylation efficiency for borneol-type substrates and . These findings offer key genetic elements for the metabolic engineering of plants and synthetic biology to produce BA.
在植物次生代谢物生物合成中，酰化是一种多样化的生理过程，BAHD 酰基转移酶发挥着重要作用。龙脑香醇基转移酶（BAT）是一种醇酰基转移酶，可催化龙脑和乙酰辅酶 A 合成乙酸龙脑酯（BA）。然而，目前为止，BA 生物合成中涉及的酶仅在 中得到了表征，对 WvBATs 的研究仅在 中进行，且催化活性相对较低。在这项研究中，我们鉴定了三个基因（ 、 和 ），它们编码能够酰化龙脑醇以合成 BA 的 BATs。我们还确定 WlBAT1 对龙脑醇型底物（包括 (+)-龙脑醇、(-)-龙脑醇和异龙脑醇）具有最高的催化效率。此外，我们发现 BATs 可以催化广泛的底物类型，但 ，它们只催化龙脑醇型底物。通过分子模拟和定点突变，揭示了残基 D32、N36、H168、N297、N355 和 H384 对 WlBAT1 的催化活性至关重要，而 WlBAT1 的 R382I-D385R 双突变体显示出对龙脑醇型底物的酰化效率增加 。这些发现为植物代谢工程和合成生物学生产 BA 提供了关键的遗传要素。
