The biosynthetic pathway for the production of dTDP-L-rhamnose is composed of four enzymes. The first enzyme, glucose-1-phosphate thymidylyltransferase, is the control enzyme of the pathway and is capable of utilizing dTTP or UTP. This pathway is essential for production of the activated sugar dTDP-L-rhamnose for capsular polysaccharide synthesis in gram-positive bacteria, and it is absent in humans. Thus, this pathway is a good candidate for drug discovery efforts. Our structure is the first one of this enzyme in gram-positive bacteria, and it contains a sucrose molecule bound in the active site.