View source for 5ndf


==Small-molecule inhibition of ppGalNAc-Ts selectively reduces mucin-type O-glycosylation==
<StructureSection load='5ndf' size='340' side='right'caption='[[5ndf]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ndf]] is a 6 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=5NDF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5NDF 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=LU2:2-(3,4-DIHYDROXYPHENYL)-5,7-DIHYDROXY-4H-CHROMEN-4-ONE'>LU2</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</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=5ndf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ndf OCA], [https://pdbe.org/5ndf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ndf RCSB], [https://www.ebi.ac.uk/pdbsum/5ndf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ndf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GALT2_HUMAN GALT2_HUMAN] Catalyzes the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor. Has a broad spectrum of substrates for peptides such as EA2, Muc5AC, Muc1a, Muc1b. Probably involved in O-linked glycosylation of the immunoglobulin A1 (IgA1) hinge region.<ref>PMID:9295285</ref> <ref>PMID:12438318</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Mucin-type O-glycosylation is the most abundant type of O-glycosylation. It is initiated by the members of polypeptide N-acetyl-alpha-galactosaminyltransferase (ppGalNAc-T) family and closely associated with both physiological and pathological conditions such as coronary artery disease or Alzheimer' s disease. The lack of direct and selective inhibitors of ppGalNAc-Ts has largely impeded research progress in understanding the molecular events in mucin-type O-glycosylation. Here, we report that a small molecule, the plant flavonoid luteolin, selectively inhibits ppGalNAc-Ts in vitro and in cells. We found that luteolin inhibits ppGalNAc-T2 through a peptide/protein-competitive manner but not promiscuously, e.g. via aggregation-based activity. X-ray structural analysis revealed that luteolin binds to the PxP motif-binding site found in most protein substrates, which was further validated by comparing the interactions between luteolin with wildtype enzyme and mutants using 1H NMR-based binding experiments. Functional studies disclosed that luteolin at least partially reduced production of beta-amyloid (Abeta) protein by selectively inhibiting the activity of ppGalNAc-T isoforms. In conclusion, our study provides key structural and functional details on luteolin inhibiting ppGalNAc-T activity, opening up the way for further optimization of more potent and specific ppGalNAc-T inhibitors. Moreover, our findings may inform future investigations into site-specific O-GalNAc glycosylation and into the molecular mechanism of luteolin-mediated ppGalNAc-T inhibition.

The small molecule luteolin inhibits N-acetyl-alpha-galactosaminyltransferases and reduces mucin-type O-glycosylation of amyloid precursor protein.,Liu F, Xu K, Xu Z, Rivas ML, Li X, Lu J, Delso I, Merino P, Hurtado-Guerrero R, Zhang Y J Biol Chem. 2017 Oct 23. pii: jbc.M117.814202. doi: 10.1074/jbc.M117.814202. PMID:29061849<ref>PMID:29061849</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5ndf" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: De las Rivas M]]
[[Category: Hurtado-Guerrero R]]