title: O-GlcNAc transferase invokes nucleotide sugar pyrophosphate participation in catalysis.
abstract: Protein O-GlcNAcylation is an essential post-translational modification on hundreds of intracellular proteins in metazoa, catalyzed by O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT) using unknown mechanisms of transfer and substrate recognition. Through crystallographic snapshots and mechanism-inspired chemical probes, we define how human OGT recognizes the sugar donor and acceptor peptide and uses a new catalytic mechanism of glycosyl transfer, involving the sugar donor α-phosphate as the catalytic base as well as an essential lysine. This mechanism seems to be a unique evolutionary solution to the spatial constraints imposed by a bulky protein acceptor substrate and explains the unexpected specificity of a recently reported metabolic OGT inhibitor.
authors.affiliation: College of Life Sciences, University of Dundee, Dundee, UK.
authors.forename: Marianne
authors.initials: M
authors.lastname: Schimpl
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zheng
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Borodkin
authors.forename: David E
authors.initials: DE
authors.lastname: Blair
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Ferenbach
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Schüttelkopf
authors.forename: Iva
authors.initials: I
authors.lastname: Navratilova
authors.forename: Tonia
authors.initials: T
authors.lastname: Aristotelous
authors.forename: Osama
authors.initials: O
authors.lastname: Albarbarawi
authors.forename: David A
authors.initials: DA
authors.lastname: Robinson
authors.forename: Megan A
authors.initials: MA
authors.lastname: Macnaughtan
authors.forename: Daan M F
authors.initials: DM
authors.lastname: van Aalten
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D002384:Catalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D011756:Diphosphates / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008239:Lysine / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D009711:Nucleotides / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D013237:Stereoisomerism; D013379:Substrate Specificity; D020349:Surface Plasmon Resonance; D014531:Uridine Diphosphate Galactose / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D011756:Diphosphates; D009711:Nucleotides; D010710:Phosphates; C486300:TAB1 protein, human; D014531:Uridine Diphosphate Galactose; C107241:diphosphoric acid; D017351:N-Acetylglucosaminyltransferases; C449880:O-GlcNAc transferase; D008239:Lysine