Download MendeleyEnzymatic beta-elimination in natural product O- and C-glycoside deglycosylation.
Bitter, J., Pfeiffer, M., Borg, A.J.E., Kuhlmann, K., Pavkov-Keller, T., Sanchez-Murcia, P.A., Nidetzky, B.(2023) Nat Commun 14: 7123-7123
- PubMed: 37932298
- DOI: https://doi.org/10.1038/s41467-023-42750-0
- Primary Citation of Related Structures:
8BVK - PubMed Abstract:
Biological degradation of natural product glycosides involves, alongside hydrolysis, β-elimination for glycosidic bond cleavage. Here, we discover an O-glycoside β-eliminase (OGE) from Agrobacterium tumefaciens that converts the C3-oxidized O-β-D-glucoside of phloretin (a plant-derived flavonoid) into the aglycone and the 2-hydroxy-3-keto-glycal elimination product. While unrelated in sequence, OGE is structurally homologous to, and shows effectively the same Mn 2+ active site as, the C-glycoside deglycosylating enzyme (CGE) from a human intestinal bacterium implicated in β-elimination of 3-keto C-β-D-glucosides. We show that CGE catalyzes β-elimination of 3-keto O- and C-β-D-glucosides while OGE is specific for the O-glycoside substrate. Substrate comparisons and mutagenesis for CGE uncover positioning of aglycone for protonic assistance by the enzyme as critically important for C-glycoside cleavage. Collectively, our study suggests convergent evolution of active site for β-elimination of 3-keto O-β-D-glucosides. C-Glycoside cleavage is a specialized feature of this active site which is elicited by substrate through finely tuned enzyme-aglycone interactions.
Organizational Affiliation:
Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, NAWI Graz, Petersgasse 12, A-8010, Graz, Austria.
