8ZI6

Crystal structure of SrUGT76G4 in complex with UDP-glucose

8ZI6 の概要

• エントリーDOI: 10.2210/pdb8zi6/pdb
• 分子名称: UGT-glycosyltransferase 76G4, URIDINE-5'-DIPHOSPHATE-GLUCOSE, ISOPROPYL ALCOHOL, ... (5 entities in total)
• 機能のキーワード: glycosyltransferase, steviol glycosides, udp-glucose, complex, transferase
• 由来する生物種: Stevia rebaudiana
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 157791.76

構造登録者

Wang, Y.,Li, T.,Yin, H. (登録日: 2024-05-13, 公開日: 2025-05-21, 最終更新日: 2025-12-03)

主引用文献

Wang, Y.,Li, T.,Zheng, Y.,Guo, C.,Li, K.,Jia, X.,Zhu, L.,Chen, K.,Yin, H.
Characterization of Sr UGT76G4 reveals a key residue for regioselectivity and efficient Reb M synthesis.
Proc.Natl.Acad.Sci.USA, 122:e2504698122-e2504698122, 2025

PubMed Abstract: Steviol glycosides (SGs) from are prized as noncaloric sweeteners, with rebaudioside M (Reb M)-a next-generation SG known for its sucrose-like sweetness and lack of off-tastes-standing out for its superior sensory profile. However, Reb M's limited natural abundance impedes its commercial production. Here, we report the identification of a glucosyltransferase, UGT76G4 that efficiently catalyzes the conversion of Reb D to Reb M with a strong preference for C19 glycosylation. Structural and functional analyses, including X-ray crystallography, molecular dynamics simulations, and mutagenesis, revealed key residues in UGT76G4 that dictate its regioselectivity, with residue 200 playing a pivotal role. Engineered UGT76G4 variants, including Q199I/G200Y and H155S/Q199I/G200Y, enhanced Reb E and Reb D conversion efficiency by 1.46-fold and 23-fold, respectively, compared to UGT76G1. The engineered variants offer a promising pathway for increasing Reb M production, advancing biotechnological strategies for steviol glycoside biosynthesis and optimizing plant metabolic engineering approaches. Our findings deepen the understanding of SG biosynthesis and provide a basis for sustainable production of high-value sweeteners.

PubMed: 40961143
DOI: 10.1073/pnas.2504698122

実験手法

X-RAY DIFFRACTION (2.8 Å)