8HBT

AmAT7-3 mutant A310G

8HBT の概要

• エントリーDOI: 10.2210/pdb8hbt/pdb
• 分子名称: AmAT7-3-A310G, Astragaloside IV (3 entities in total)
• 機能のキーワード: acetyltransferase, triterpene saponin, mutant, biosynthetic protein
• 由来する生物種: Astragalus membranaceus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 50759.44

構造登録者

Wang, L.L. (登録日: 2022-10-31, 公開日: 2023-09-13, 最終更新日: 2024-02-14)

主引用文献

Wang, L.,Jiang, Z.,Zhang, J.,Chen, K.,Zhang, M.,Wang, Z.,Wang, B.,Ye, M.,Qiao, X.
Characterization and structure-based protein engineering of a regiospecific saponin acetyltransferase from Astragalus membranaceus.
Nat Commun, 14:5969-5969, 2023

PubMed Abstract: Acetylation contributes to the bioactivity of numerous medicinally important natural products. However, little is known about the acetylation on sugar moieties. Here we report a saponin acetyltransferase from Astragalus membranaceus. AmAT7-3 is discovered through a stepwise gene mining approach and characterized as the xylose C3'/C4'-O-acetyltransferse of astragaloside IV (1). To elucidate its catalytic mechanism, complex crystal structures of AmAT7-3/1 and AmAT7-3/1 are obtained, which reveal a large active pocket decided by a specific sequence AADAG. Combining with QM/MM computation, the regiospecificity of AmAT7-3 is determined by sugar positioning modulated by surrounding amino acids including #A310 and #L290. Furthermore, a small mutant library is built using semi-rational design, where variants A310G and A310W are found to catalyze specific C3'-O and C4'-O acetylation, respectively. AmAT7-3 and its variants are also employed to acetylate other bioactive saponins. This work expands the understanding of saponin acetyltransferases, and provide efficient catalytic tools for saponin acetylation.

PubMed: 37749089
DOI: 10.1038/s41467-023-41599-7

実験手法

X-RAY DIFFRACTION (1.96 Å)