6jtd

Publication Abstract from PubMed

In this work, we explored the catalytic promiscuity of TcCGT1, a new C-glycosyltransferase (CGT) from the medicinal plant Trollius chinensis. TcCGT1 could efficiently and regio-specifically catalyze 8-C-glycosylation of 36 flavones and other flavonoids, and could also catalyze the O-glycosylation of diverse phenolics. Moreover, the crystal structure of TcCGT1 in complex with uridine diphosphate was determined at 1.85 A resolution. Structural analysis with molecular docking revealed a new model for catalytic mechanism of TcCGT1, which was initiated by substrate spontaneous deprotonation. The spacious binding pocket explains the robust substrate promiscuity, and binding pose of the substrate determines C- or O-glycosylation activity. Site-directed mutagenesis at two residues (I94E and G284K) switched C- to O-glycosylation. This work highlights TcCGT1 as the first plant CGT with a crystal structure and the first flavone 8-C-glycosyltransferase, and provides a basis for protein engineering to design efficient glycosylation biocatalysts for drug discovery.

Molecular Characterization and Structural Basis of a Promiscuous C-Glycosyltransferase from Trollius chinensis.,He JB, Zhao P, Hu ZM, Liu S, Kuang Y, Zhang M, Li B, Yun CH, Qiao X, Ye M Angew Chem Int Ed Engl. 2019 Jun 4. doi: 10.1002/anie.201905505. PMID:31163097^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.