This family of glycosyltransferases includes O-linked beta-N-acetylglucosamine (O-GlcNAc) transferase, an enzyme which catalyses the addition of O-GlcNAc to serine and threonine residues [1,2]. In addition to its function as an O-GlcNAc transferase, human OGT, Swiss:O15294, also appears to proteolytically cleave the epigenetic cell-cycle regulator HCF-1 [3].

1: Structural insights into mechanism and specificity of O-GlcNAc transferase. Clarke AJ, Hurtado-Guerrero R, Pathak S, Schuttelkopf AW, Borodkin V, Shepherd SM, Ibrahim AF, van Aalten DM; EMBO J. 2008;27:2780-2788. PMID:18818698

2: Structure of an O-GlcNAc transferase homolog provides insight into intracellular glycosylation. Martinez-Fleites C, Macauley MS, He Y, Shen DL, Vocadlo DJ, Davies GJ; Nat Struct Mol Biol. 2008;15:764-765. PMID:18536723

3: O-GlcNAc Transferase Catalyzes Site-Specific Proteolysis of HCF-1. Capotosti F, Guernier S, Lammers F, Waridel P, Cai Y, Jin J, Conaway JW, Conaway RC, Herr W; Cell. 2011;144:376-388. PMID:21295698