View source for 5un8


==Crystal Structure of human O-GlcNAcase in complex with glycopeptide p53==
<StructureSection load='5un8' size='340' side='right'caption='[[5un8]], [[Resolution|resolution]] 2.13&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5un8]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5UN8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5UN8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.13&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5un8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5un8 OCA], [https://pdbe.org/5un8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5un8 RCSB], [https://www.ebi.ac.uk/pdbsum/5un8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5un8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/OGA_HUMAN OGA_HUMAN] Isoform 1: Cleaves GlcNAc but not GalNAc from O-glycosylated proteins. Can use p-nitrophenyl-beta-GlcNAc and 4-methylumbelliferone-GlcNAc as substrates but not p-nitrophenyl-beta-GalNAc or p-nitrophenyl-alpha-GlcNAc (in vitro) (PubMed:11148210). Does not bind acetyl-CoA and does not have histone acetyltransferase activity (PubMed:24088714).<ref>PMID:11148210</ref> <ref>PMID:11788610</ref> <ref>PMID:20673219</ref> <ref>PMID:22365600</ref> <ref>PMID:24088714</ref>   Isoform 3: Cleaves GlcNAc but not GalNAc from O-glycosylated proteins. Can use p-nitrophenyl-beta-GlcNAc as substrate but not p-nitrophenyl-beta-GalNAc or p-nitrophenyl-alpha-GlcNAc (in vitro), but has about six times lower specific activity than isoform 1.<ref>PMID:20673219</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human O-GlcNAcase (hOGA) is the unique enzyme responsible for the hydrolysis of the O-linked beta-N-acetyl glucosamine (O-GlcNAc) modification, an essential protein glycosylation event that modulates the function of numerous cellular proteins in response to nutrients and stress. Here we report crystal structures of a truncated hOGA, which comprises the catalytic and stalk domains, in apo form, in complex with an inhibitor, and in complex with a glycopeptide substrate. We found that hOGA forms an unusual arm-in-arm homodimer in which the catalytic domain of one monomer is covered by the stalk domain of the sister monomer to create a substrate-binding cleft. Notably, the residues on the cleft surface afford extensive interactions with the peptide substrate in a recognition mode that is distinct from that of its bacterial homologs. These structures represent the first model of eukaryotic enzymes in the glycoside hydrolase 84 (GH84) family and provide a crucial starting point for understanding the substrate specificity of hOGA, which regulates a broad range of biological and pathological processes.

Structures of human O-GlcNAcase and its complexes reveal a new substrate recognition mode.,Li B, Li H, Lu L, Jiang J Nat Struct Mol Biol. 2017 Mar 20. doi: 10.1038/nsmb.3390. PMID:28319083<ref>PMID:28319083</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5un8" style="background-color:#fffaf0;"></div>

==See Also==
*[[O-GlcNAcase|O-GlcNAcase]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Jiang J]]
[[Category: Li B]]