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Luo Y, Ma X, Qiu Y, Lu Y, Shen S, Li Y, Gao H, Chen K, Zhou J, Hu T, Tu L, Zhao H, Li D, Leng F, Gao W, Jiang T, Liu C, Huang L, Wu R, Tong Y. Structural and Catalytic Insight into the Unique Pentacyclic Triterpene Synthase TwOSC. Angew Chem Int Ed Engl 2023; 62:e202313429. [PMID: 37840440 DOI: 10.1002/anie.202313429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/17/2023]
Abstract
The oxidosqualene cyclase (OSC) catalyzed cyclization of the linear substrate (3S)-2,3-oxidosqualene to form diverse pentacyclic triterpenoid (PT) skeletons is one of the most complex reactions in nature. Friedelin has a unique PT skeleton involving a fascinating nine-step cation shuttle run (CSR) cascade rearrangement reaction, in which the carbocation formed at C2 moves to the other side of the skeleton, runs back to C3 to yield a friedelin cation, which is finally deprotonated. However, as crystal structure data of plant OSCs are lacking, it remains unknown why the CSR cascade reactions occur in friedelin biosynthesis, as does the exact catalytic mechanism of the CSR. In this study, we determined the first cryogenic electron microscopy structure of a plant OSC, friedelin synthase, from Tripterygium wilfordii Hook. f (TwOSC). We also performed quantum mechanics/molecular mechanics simulations to reveal the energy profile for the CSR cascade reaction and identify key residues crucial for PT skeleton formation. Furthermore, we semirationally designed two TwOSC mutants, which significantly improved the yields of friedelin and β-amyrin, respectively.
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Affiliation(s)
- Yunfeng Luo
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Xiaoli Ma
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yufan Qiu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yun Lu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Siyu Shen
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Yang Li
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, 100069, China
| | - Haiyun Gao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Kang Chen
- State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Media, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jiawei Zhou
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Tianyuan Hu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Lichan Tu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Huan Zhao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Dan Li
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, 100069, China
| | - Faqiang Leng
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, 100069, China
| | - Wei Gao
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Tao Jiang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Changli Liu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, 100069, China
| | - Luqi Huang
- State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Media, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Ruibo Wu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yuru Tong
- School of Pharmaceutical Sciences, Capital Medical University, Beijing, 100069, China
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