PMID: 23103942
Schimpl M, Zheng X, Borodkin VS, Blair DE, Ferenbach AT, Schuttelkopf AW, Navratilova I, Aristotelous T, Albarbarawi O, Robinson DA, Macnaughtan MA, van Aalten DM
O-GlcNAc transferase invokes nucleotide sugar pyrophosphate participation in catalysis.
Nat Chem Biol. 2012 Dec;8(12):969-74. doi: 10.1038/nchembio.1108. Epub 2012 Oct, 28.
Protein O-GlcNAcylation is an essential post-translational modification on hundreds of intracellular proteins in metazoa, catalyzed by O-linked beta-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 alpha-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.