Catalyzes the attachment of N-acetylglucosamine (GlcNAc) in alpha-linkage onto the 'hydroxyPro-143' residue of Skp1 (fpaA/fpaB). Is the first glycosyltransferase in the Skp1 HyPro modification pathway, which results in a pentasaccharide-linked 'HyPro-143'. trans-4-hydroxy-L-prolyl-[Skp1 protein] + UDP-N-acetyl-alpha-D-glucosamine = H(+) + O-(N-acetyl-alpha-D-glucosaminyl)-trans-4-hydroxy-L-prolyl-[Skp1 protein] + UDP Requires dithiothreitol (DTT) for activity in vitro. Activated by Tween 20 or Tween 80 in vitro. Inhibited by UMP, UDP, UTP, 4-thio-UMP, Bio-11-UTP, and UDP-Glc but not by uridine, dUDP, dUMP, UDP-hexanolamine, and CTP. Also inhibited by EDTA. The low Vmax value suggests that the enzyme may be down-regulated under the assay conditions. Optimum pH is 7.5-8. Activity is less than 10% at pH 6.0. Optimum temperature is 30-33 degrees Celsius. Protein modification; protein glycosylation. Monomer. The C-terminal 65 amino acids are required for catalytic activity. Present with 4000 molecules/cell. Belongs to the glycosyltransferase 60 family.