Skp1 is a cytoplasmic and nuclear protein required for the ubiquitination of cell cycle regulatory proteins and transcriptional factors. In Dictyostelium Skp1 is modified by the linear pentasaccharide Galalpha1-6Galalpha1-L-Fucalpha1-2Galbeta1-3GlcNAc, which is attached to a hydroxyproline residue at position 143. This enzyme catalyses the first step in the building up of the pentasaccharide by attaching an N-acetylglucosaminyl group to the hydroxyproline residue. It requires dithiothreitol and a divalent cation for activity.
Van Der Wel H, Morris HR, Panico M, Paxton T, Dell A, Kaplan L, West CM
Title
Molecular cloning and expression of a UDP-N-acetylglucosamine (GlcNAc):hydroxyproline polypeptide GlcNAc-transferase that modifies Skp1 in the cytoplasm of dictyostelium.