Functional characterization of a C-glycosyltransferase from Pueraria lobata with dual-substrate selectivity

We report a C-glycosyltransferase PlCGT from Pueraria lobata. PlCGT exhibits efficient C-glycosylation activities toward two types of substrates (isoflavones and phloroglucinol derivatives). Homology modelling reveals that a narrow hydrophobic pocket is responsible for its substrate selectivity. An unusual Asn16-Asp124 dyad in the pocket may mediate the SN2-like mechanism in C-glycosylation.