State Key Laboratory of Bioactive Substance and Function of Natural Medicines, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs and NHC Key Laboratory of Biosynthesis of Natural Products, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
J Am Chem Soc. 2024 Apr 10;146(14):9614-9622. doi: 10.1021/jacs.3c12895. Epub 2024 Mar 28.
Glycosides make up a biomedically important class of secondary metabolites. Most naturally occurring glycosides were isolated from plants and bacteria; however, the chemical diversity of glycosylated natural products in fungi remains largely unexplored. Herein, we present a paradigm to specifically discover diverse and bioactive glycosylated natural products from fungi by combining tailoring enzyme-guided genome mining with mass spectrometry (MS)-based metabolome analysis. Through genes deletion and heterologous expression, the first fungal -glycosyltransferase AuCGT involved in the biosynthesis of stromemycin was identified from . Subsequent homology-based genome mining for fungal glycosyltransferases by using AuCGT as a probe revealed a variety of biosynthetic gene clusters (BGCs) containing its homologues in diverse fungi, of which the glycoside-producing capability was corroborated by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. Consequently, 28 fungal aromatic polyketide /-glycosides, including 20 new compounds, were efficiently discovered and isolated from the three selected fungi. Moreover, several novel fungal /-glycosyltransferases, especially three novel α-pyrone -glycosyltransferases, were functionally characterized and verified in the biosynthesis of these glycosides. In addition, a proof of principle for combinatorial biosynthesis was applied to design the production of unnatural glycosides in . Notably, the newly discovered glycosides exhibited significant antiviral, antibacterial, and antidiabetic activities. Our work demonstrates the promise of tailoring enzyme-guided genome-mining approach for the targeted discovery of fungal glycosides and promotes the exploration of a broader chemical space for natural products with a target structural motif in microbial genomes.
糖苷构成了一类具有重要生物医学意义的次生代谢产物。大多数天然存在的糖苷是从植物和细菌中分离出来的；然而，真菌中糖基化天然产物的化学多样性在很大程度上仍未被探索。在此，我们提出了一种通过结合靶向酶指导的基因组挖掘与基于质谱（MS）的代谢组学分析来专门从真菌中发现多样和具有生物活性的糖基化天然产物的范例。通过基因缺失和异源表达，从 中鉴定出第一个参与stromemycin 生物合成的真菌 -糖苷转移酶 AuCGT。随后，使用 AuCGT 作为探针，通过同源性基因组挖掘，发现了各种包含其同源物的真菌糖苷转移酶生物合成基因簇（BGCs），其中通过高效液相色谱-质谱（HPLC-MS）分析证实了糖苷产生能力。因此，从三种选定的真菌中高效发现和分离了 28 种真菌芳香聚酮/-糖苷，包括 20 种新化合物。此外，还对几种新型真菌/-糖苷转移酶，特别是三种新型α-吡喃酮/-糖苷转移酶，进行了功能表征和在这些糖苷生物合成中的验证。此外，还应用组合生物合成的原理设计了在 中产生非天然糖苷。值得注意的是，新发现的糖苷表现出显著的抗病毒、抗菌和抗糖尿病活性。我们的工作证明了靶向酶指导的基因组挖掘方法在真菌糖苷的靶向发现方面具有广阔的前景，并促进了对微生物基因组中具有目标结构模体的天然产物的更广泛化学空间的探索。
