View source for 3vnk


==Crystal structures of D-Psicose 3-epimerase with D-fructose from Clostridium cellulolyticum H10==
<StructureSection load='3vnk' size='340' side='right'caption='[[3vnk]], [[Resolution|resolution]] 2.02&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3vnk]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Ruminiclostridium_cellulolyticum_H10 Ruminiclostridium cellulolyticum H10]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3VNK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3VNK 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]] 2.02&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FUD:D-FRUCTOSE'>FUD</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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=3vnk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3vnk OCA], [https://pdbe.org/3vnk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3vnk RCSB], [https://www.ebi.ac.uk/pdbsum/3vnk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3vnk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DPES_RUMCH DPES_RUMCH] Involved in the biosynthesis of D-psicose. Catalyzes the reversible epimerization of D-fructose at the C3 position to yield D-psicose. The enzyme is highly specific for D-psicose and shows very low activity with D-tagatose.<ref>PMID:21663329</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
D-psicose 3-epimerase (DPEase) is demonstrated to be useful in the bioproduction of D-psicose, a rare hexose sugar, from D-fructose, found plenty in nature. Clostridium cellulolyticum H10 has recently been identified as a DPEase that can epimerize D-fructose to yield D-psicose with a much higher conversion rate when compared with the conventionally used DTEase. In this study, the crystal structure of the C. cellulolyticum DPEase was determined. The enzyme assembles into a tetramer and each subunit shows a (beta/alpha)(8) TIM barrel fold with a Mn(2+) metal ion in the active site. Additional crystal structures of the enzyme in complex with substrates/products (D-psicose, D-fructose, D-tagatose and D-sorbose) were also determined. From the complex structures of C. cellulolyticum DPEase with D-psicose and D-fructose, the enzyme has much more interactions with D-psicose than D-fructose by forming more hydrogen bonds between the substrate and the active site residues. Accordingly, based on these ketohexose-bound complex structures, a C3-O3 proton-exchange mechanism for the conversion between D-psicose and D-fructose is proposed here. These results provide a clear idea for the deprotonation/protonation roles of E150 and E244 in catalysis.

Crystal structures of D-psicose 3-epimerase from Clostridium cellulolyticum H10 and its complex with ketohexose sugars.,Chan HC, Zhu Y, Hu Y, Ko TP, Huang CH, Ren F, Chen CC, Ma Y, Guo RT, Sun Y Protein Cell. 2012 Feb;3(2):123-31. Epub 2012 Mar 17. PMID:22426981<ref>PMID:22426981</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3vnk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Ruminiclostridium cellulolyticum H10]]
[[Category: Chan HC]]
[[Category: Chen CC]]
[[Category: Guo RT]]
[[Category: Hu Y]]
[[Category: Huang CH]]
[[Category: Ko TP]]
[[Category: Ren F]]
[[Category: Sun Y]]
[[Category: Zhu Y]]