ENZYME

ENZYME entry: EC 2.4.1.229

Accepted Name

[Skp1-protein]-hydroxyproline N-acetylglucosaminyltransferase.

Alternative Name(s)

Skp1-HyPro GlcNAc-transferase.

UDP-GlcNAc:hydroxyproline polypeptide GlcNAc-transferase.

UDP-GlcNAc:Skp1-hydroxyproline GlcNAc-transferase.

UDP-N-acetylglucosamine (GlcNAc):hydroxyproline polypeptide GlcNAc- transferase.

Reaction catalysed

UDP-N-acetylglucosamine + [Skp1-protein]-hydroxyproline <=> UDP + [Skp1-protein]-O-(N-acetyl-D-glucosaminyl)hydroxyproline

Comment(s)

Requires dithiothreitol and a divalent cation for activity.
This enzyme commences the building up of a pentasaccharide (Gal- alpha-1-6Gal-alpha-1-L-Fuc-alpha-1-2Gal-beta-1-3GlcNAc) on Hyp-143 of the Dictyostelium protein Skp1, which is required for the ubiquitination of cell-cycle regulatory proteins and transcription factors.
The fucose residue is probably in the alpha configuration.
The specificity of the enzyme for Skp1-Hyp-143 and its high affinity for this substrate suggests that it is the GlcNAc-transferase that modifies Skp1 in vivo.

Cross-references

BRENDA

EC2PDB

ExplorEnz

PRIAM enzyme-specific profiles

KEGG Ligand Database for Enzyme Nomenclature

IUBMB Enzyme Nomenclature