Abstract
Family 1 glycosyltransferases (UGTs) attract considerable interest as suitable candidates of biocatalysts for metabolic engineering from the biotechnology community. Current investigation on 3D-structures of UGTs revealed the role of the conserved amino acid residues in the PSPG-box that constitute the donor-sugar binding pockets. However, the roles of less conserved amino acids in this motif that may decide the characteristics unique to particular enzymes such as substrate recognition and catalytic potential have been less understood. We have recently cloned a cDNA encoding a novel glucosyltransferase, UDP-glucose: curcumin glucosyltransferase (CaUGT2), from Catharanthus roseus cultured cells. In this study, we report that a single amino acid in the PSPG-box plays important role in the catalytic activity of CaUGT2.
