DTDP-L-rhamnose 4-epimerase (, dTDP-4-L-rhamnose 4-epimerase, wbiB (gene)) is an enzyme with systematic name dTDP-6-deoxy-beta-L-talose 4-epimerase. This enzyme catalyses the following chemical reaction
The equilibrium is strongly towards dTDP-6-deoxy-beta-L-mannose.