View source for 5hgv


==Structure of an O-GlcNAc transferase point mutant, D554N in complex with peptide==
<StructureSection load='5hgv' size='340' side='right'caption='[[5hgv]], [[Resolution|resolution]] 2.05&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5hgv]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5HGV OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5HGV FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">OGT ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Protein_O-GlcNAc_transferase Protein O-GlcNAc transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.255 2.4.1.255] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5hgv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5hgv OCA], [http://pdbe.org/5hgv PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5hgv RCSB], [http://www.ebi.ac.uk/pdbsum/5hgv PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5hgv ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/OGT1_HUMAN OGT1_HUMAN]] Regulation of OGT activity and altered O-GlcNAcylations are implicated in diabetes and Alzheimer disease. O-GlcNAcylation of AKT1 affects insulin signaling and, possibly diabetes. Reduced O-GlcNAcylations and resulting increased phosphorylations of MAPT/TAU are observed in Alzheimer disease (AD) brain cerebrum. 
== Function ==
[[http://www.uniprot.org/uniprot/OGT1_HUMAN OGT1_HUMAN]] Catalyzes the transfer of a single N-acetylglucosamine from UDP-GlcNAc to a serine or threonine residue in cytoplasmic and nuclear proteins resulting in their modification with a beta-linked N-acetylglucosamine (O-GlcNAc). Glycosylates a large and diverse number of proteins including histone H2B, AKT1, PFKL, KMT2E/MLL5, MAPT/TAU and HCFC1. Can regulate their cellular processes via cross-talk between glycosylation and phosphorylation or by affecting proteolytic processing. Involved in insulin resistance in muscle and adipocyte cells via glycosylating insulin signaling components and inhibiting the 'Thr-308' phosphorylation of AKT1, enhancing IRS1 phosphorylation and attenuating insulin signaling. Involved in glycolysis regulation by mediating glycosylation of 6-phosphofructokinase PFKL, inhibiting its activity. Component of a THAP1/THAP3-HCFC1-OGT complex that is required for the regulation of the transcriptional activity of RRM1. Plays a key role in chromatin structure by mediating O-GlcNAcylation of 'Ser-112' of histone H2B: recruited to CpG-rich transcription start sites of active genes via its interaction with TET proteins (TET1, TET2 or TET3). As part of the NSL complex indirectly involved in acetylation of nucleosomal histone H4 on several lysine residues.<ref>PMID:12150998</ref> <ref>PMID:18288188</ref> <ref>PMID:19451179</ref> <ref>PMID:19377461</ref> <ref>PMID:20018852</ref> <ref>PMID:20018868</ref> <ref>PMID:20200153</ref> <ref>PMID:20824293</ref> <ref>PMID:21285374</ref> <ref>PMID:22121020</ref> <ref>PMID:22923583</ref> <ref>PMID:23353889</ref> <ref>PMID:23222540</ref> <ref>PMID:15361863</ref> <ref>PMID:21240259</ref>   Isoform 2: the mitochondrial isoform (mOGT) is cytotoxic and triggers apoptosis in several cell types including INS1, an insulinoma cell line.<ref>PMID:12150998</ref> <ref>PMID:18288188</ref> <ref>PMID:19451179</ref> <ref>PMID:19377461</ref> <ref>PMID:20018852</ref> <ref>PMID:20018868</ref> <ref>PMID:20200153</ref> <ref>PMID:20824293</ref> <ref>PMID:21285374</ref> <ref>PMID:22121020</ref> <ref>PMID:22923583</ref> <ref>PMID:23353889</ref> <ref>PMID:23222540</ref> <ref>PMID:15361863</ref> <ref>PMID:21240259</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The essential human enzyme O-linked beta-N-acetylglucosamine transferase (OGT), known for modulating the functions of nuclear and cytoplasmic proteins through serine and threonine glycosylation, was unexpectedly implicated in the proteolytic maturation of the cell cycle regulator host cell factor-1 (HCF-1). Here we show that HCF-1 cleavage occurs via glycosylation of a glutamate side chain followed by on-enzyme formation of an internal pyroglutamate, which undergoes spontaneous backbone hydrolysis.

How the glycosyltransferase OGT catalyzes amide bond cleavage.,Janetzko J, Trauger SA, Lazarus MB, Walker S Nat Chem Biol. 2016 Sep 12. doi: 10.1038/nchembio.2173. PMID:27618188<ref>PMID:27618188</ref>

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

==See Also==
*[[O-GlcNAc transferase 3D structures|O-GlcNAc transferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Protein O-GlcNAc transferase]]
[[Category: Janetzko, J]]
[[Category: Lazarus, M B]]
[[Category: Walker, S]]
[[Category: Glycosyltransferase]]
[[Category: Ogt]]
[[Category: Point mutant]]
[[Category: Transferase-peptide complex]]