View source for 4rjt


==Crystal Structure of Unliganded, Full Length hUGDH at pH 7.0==
<StructureSection load='4rjt' size='340' side='right'caption='[[4rjt]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4rjt]] is a 3 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=4RJT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RJT 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=4rjt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rjt OCA], [https://pdbe.org/4rjt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rjt RCSB], [https://www.ebi.ac.uk/pdbsum/4rjt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rjt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/UGDH_HUMAN UGDH_HUMAN] Involved in the biosynthesis of glycosaminoglycans; hyaluronan, chondroitin sulfate, and heparan sulfate.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human UDP-alpha-d-glucose-6-dehydrogenase (hUGDH) displays hysteresis because of a slow isomerization from an inactive state (E*) to an active state (E). Here we show that the structure of E* constrains hUGDH in a conformation that favors feedback inhibition at physiological pH. The feedback inhibitor UDP-alpha-d-xylose (UDP-Xyl) competes with the substrate UDP-alpha-d-glucose for the active site. Upon binding, UDP-Xyl triggers an allosteric switch that changes the structure and affinity of the intersubunit interface to form a stable but inactive horseshoe-shaped hexamer. Using sedimentation velocity studies and a new crystal structure, we show that E* represents a stable conformational intermediate between the active and feedback-inhibited conformations. Because the allosteric switch occludes the cofactor and substrate binding sites in the inactive hexamer, the intermediate conformation observed in the crystal structure is consistent with the E* transient observed in relaxation studies. Steady-state analysis shows that the E* conformation enhances the affinity of hUGDH for the allosteric inhibitor UDP-Xyl by 8.6-fold (Ki = 810 nM). We present a model in which the constrained quaternary structure permits a small effector molecule to leverage a disproportionately large allosteric response.

Hysteresis in Human UDP-Glucose Dehydrogenase Is Due to a Restrained Hexameric Structure That Favors Feedback Inhibition.,Kadirvelraj R, Custer GS, Keul ND, Sennett NC, Sidlo AM, Walsh RM Jr, Wood ZA Biochemistry. 2014 Dec 30;53(51):8043-51. doi: 10.1021/bi500594x. Epub 2014 Dec, 18. PMID:25478983<ref>PMID:25478983</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4rjt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Sidlo AM]]
[[Category: Wood ZA]]