View source for 2vnc


==Crystal structure of Glycogen Debranching enzyme TreX from Sulfolobus solfataricus==
<StructureSection load='2vnc' size='340' side='right'caption='[[2vnc]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vnc]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus Saccharolobus solfataricus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VNC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VNC 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]] 3&#8491;</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=2vnc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vnc OCA], [https://pdbe.org/2vnc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vnc RCSB], [https://www.ebi.ac.uk/pdbsum/2vnc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vnc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/P95868_SACSO P95868_SACSO] 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/vn/2vnc_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2vnc ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
TreX is an archaeal glycogen-debranching enzyme that exists in two oligomeric states in solution, as a dimer and tetramer. Unlike its homologs, TreX from Sulfolobus solfataricus shows dual activities for alpha-1,4-transferase and alpha-1,6-glucosidase. To understand this bifunctional mechanism, we determined the crystal structure of TreX in complex with an acarbose ligand. The acarbose intermediate was covalently bound to Asp363, occupying subsites -1 to -3. Although generally similar to the monomeric structure of isoamylase, TreX exhibits two different active-site configurations depending on its oligomeric state. The N terminus of one subunit is located at the active site of the other molecule, resulting in a reshaping of the active site in the tetramer. This is accompanied by a large shift in the "flexible loop" (amino acids 399-416), creating connected holes inside the tetramer. Mutations in the N-terminal region result in a sharp increase in alpha-1,4-transferase activity and a reduced level of alpha-1,6-glucosidase activity. On the basis of geometrical analysis of the active site and mutational study, we suggest that the structural lid (acids 99-97) at the active site generated by the tetramerization is closely associated with the bifunctionality and in particular with the alpha-1,4-transferase activity. These results provide a structural basis for the modulation of activities upon TreX oligomerization that may represent a common mode of action for other glycogen-debranching enzymes in higher organisms.

Structural insight into the bifunctional mechanism of the glycogen-debranching enzyme TreX from the archaeon Sulfolobus solfataricus.,Woo EJ, Lee S, Cha H, Park JT, Yoon SM, Song HN, Park KH J Biol Chem. 2008 Oct 17;283(42):28641-8. Epub 2008 Aug 14. PMID:18703518<ref>PMID:18703518</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2vnc" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharolobus solfataricus]]
[[Category: Cha H]]
[[Category: Park K-T]]
[[Category: Song H-N]]
[[Category: Woo E-J]]
[[Category: Yoon S-M]]