Glycosyltransferases involved in the biosynthesis of biologically active natural products that contain oligosaccharides

A unique characteristic of carbohydrates is their structural diversity which is greater than that of many other classes of biological compounds. Carbohydrate-containing natural products show many different biological activities and some of them have been developed as drugs for medical use. The biosynthesis of carbohydrate-containing natural products is catalysed by glycosyltransferases. In this review we will present information on the function of glycosyltransferases involved in the biosynthesis of oligosaccharide antibiotics focusing especially on urdamycins and landomycins, two angucycline antibiotics with interesting antitumor activities. We will also discuss the use of glycosyltransferases in combinatorial biosynthesis to generate new "hybrid" antibiotics.