This family represents Chondroitin N-acetylgalactosaminyltransferase. Proteins have a type II transmembrane topology. The enzyme is involved in the biosynthetic initiation and elongation of chondroitin sulphate and is the key enzyme responsible for the selective chain assembly of chondroitin/dermatan sulphate on the linkage region tetrasaccharide common to various proteoglycans containing chondroitin/dermatan sulphate or heparin/heparan sulphate chains.