Structure-based virtual screening aids the identification of glycosyltransferases in the biosynthesis of salidroside

Glycosylation plays an important role in the structural diversification of plant natural products. The identification of efficient glycosyltransferases is also a crucial step for the biosynthesis of valuable glycoside products. However, functional characterization of glycosyltransferases (GTs) from an extensive plant gene list is labour-intensive and challenging. Salidroside is a bioactive component derived from plants, widely utilized in the fields of food and medicine. Here, through transcriptome analysis and structure-based virtual screening, we identified two GTs that participated in the biosynthesis of salidroside from a rarely studied herbaceous plant, Astilbe chinensis. Ach15909 was found to possess high catalytic activity as evidenced by the determination of its catalytic parameters. The key residues that determine its catalytic activity were further determined. Additionally, Ach15909 shows a preference for substrates with a volume of <150 ų, and replacing the interdomain linker region located between the N- and C-terminal domains of Ach15909 allows it to accept substrates that were previously not catalyzable. Overall, the structure-based virtual screening approach showed high efficiency and cost-effectiveness; the successful identification of GTs in salidroside glycosylation sheds light on uncovering additional plant biosynthesis enzymes in the forthcoming research.