2.4.1.229 metabolism a hypoxia inducible factor-alpha (HIFR) type prolyl 4-hydroxylase, P4H1, and an alpha-N-acetylglucosaminyltransferase Gnt1, sequentially modify proline 143 of Skp1, a subunit of the Skp1/Cullin/F-box protein, SCF, class of E3 ubiquitin ligases 721632 2.4.1.229 additional information Gnt1 from Dictyostelium discoideum contains a stretch of 80 Asn residues and other Asn-rich inserts 721632 2.4.1.229 additional information Gnt1 from Dictyostelium purureum lacks a stretch of 80 Asn residues and other Asn-rich inserts 721632