Structural and mechanistic basis for a new mode of glycosyltransferase inhibition.

Glycosyltransferases are carbohydrate-active enzymes with essential roles in numerous important biological processes. We have developed a new donor analog for galactosyltransferases that locks a representative target enzyme in a catalytically inactive conformation, thus almost completely abolishing sugar transfer. Results with other galactosyltransferases suggest that this unique mode of glycosyltransferase inhibition may also be generally applicable to other members of this important enzyme family.