(KDO)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase (, KDO transferase, waaA (gene), kdtA (gene), Kdo transferase, 3-deoxy-D-manno-oct-2-ulosonic acid transferase, 3-deoxy-manno-octulosonic acid transferase) is an enzyme with systematic name CMP-3-deoxy-D-manno-oct-2-ulosonate:(KDO)-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase. This enzyme catalyses the following chemical reaction
The bifunctional enzyme from Escherichia coli transfers two 3-deoxy-D-manno-oct-2-ulosonate residues to lipid IVA.