Functional characterization, structural basis, and regio-selectivity control of a promiscuous flavonoid 7,4'-di--glycosyltransferase from var. .

A highly efficient and promiscuous 7,4'-di--glycosyltransferase ZjOGT3 was discovered from the medicinal plant var. . ZjOGT3 could sequentially catalyse 4'- and 7--glycosylation of flavones to produce 7,4'-di--glycosides with obvious regio-selectivity.