4XIF: Human Ogt In Complex With Udp-5s-glcnac And Substrate Peptide (keratin-7)

Citation:
Abstract
O-GlcNAc transferase (OGT) glycosylates a diverse range of intracellular proteins with O-linked N-acetylglucosamine (O-GlcNAc), an essential and dynamic post-translational modification in metazoans. Although this enzyme modifies hundreds of proteins with O-GlcNAc, it is not understood how OGT achieves substrate specificity. In this study, we describe the application of a high-throughput OGT assay to a library of peptides. We mapped sites of O-GlcNAc modification by electron transfer dissociation MS and found that they correlate with previously detected O-GlcNAc sites. Crystal structures of four acceptor peptides in complex with Homo sapiens OGT suggest that a combination of size and conformational restriction defines sequence specificity in the -3 to +2 subsites. This work reveals that although the N-terminal TPR repeats of OGT may have roles in substrate recognition, the sequence restriction imposed by the peptide-binding site makes a substantial contribution to O-GlcNAc site specificity.
PDB ID: 4XIFDownload
MMDB ID: 131446
PDB Deposition Date: 2015/1/6
Updated in MMDB: 2015/09
Experimental Method:
x-ray diffraction
Resolution: 3.2  Å
Source Organism:
Similar Structures:
Biological Unit for 4XIF: dimeric; determined by software (PISA)
Molecular Components in 4XIF
Label Count Molecule
Proteins (2 molecules)
1
Udp-n-acetylglucosamine--peptide N- Acetylglucosaminyltransferase 110 KDA Subunit(Gene symbol: OGT)
Molecule annotation
1
Keratin, Type II Cytoskeletal 7(Gene symbol: KRT7)
Molecule annotation
Chemicals (2 molecules)
1
1
2
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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