The enzyme UDP-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase, which transfers GlcNAc-phosphate to the oligosaccharide moiety of lysosomal enzymes that are targeted to lysosomes recognizes a common protein motif on the lysosomal enzymes as well as on the oligosaccharide moeity (Baranski, Cantor & Kornfeld, 1992).