This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:O-beta-D-xylosylprotein 4-beta-D-galactosyltransferase. Other names in common use include UDP-D-galactose:D-xylose galactosyltransferase, UDP-D-galactose:xylose galactosyltransferase, galactosyltransferase I, and uridine diphosphogalactose-xylose galactosyltransferase. This enzyme participates in chondroitin sulfate biosynthesis and glycan structures - biosynthesis 1. It employs one cofactor, manganese.