View source for 4xsm


==Crystal structure of D-tagatose 3-epimerase C66S from Pseudomonas cichorii in complex with D-talitol==
<StructureSection load='4xsm' size='340' side='right'caption='[[4xsm]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xsm]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_cichorii Pseudomonas cichorii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XSM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XSM 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=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=TLZ:D-ALTRITOL'>TLZ</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=4xsm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xsm OCA], [https://pdbe.org/4xsm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xsm RCSB], [https://www.ebi.ac.uk/pdbsum/4xsm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xsm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DT3E_PSECI DT3E_PSECI] 
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== Publication Abstract from PubMed ==
Pseudomonas cichorii D-tagatose 3-epimerase (PcDTE), which has a broad substrate specificity, efficiently catalyzes the epimerization of not only D-tagatose to D-sorbose but also D-fructose to D-psicose (D-allulose) and also recognizes the deoxy sugars as substrates. In an attempt to elucidate the substrate recognition and catalytic reaction mechanisms of PcDTE for deoxy sugars, the X-ray structures of the PcDTE mutant form with the replacement of Cys66 by Ser (PcDTE_C66S) in complexes with deoxy sugars were determined. These X-ray structures showed that substrate recognition by the enzyme at the 1-, 2-, and 3-positions is responsible for enzymatic activity and that substrate-enzyme interactions at the 4-, 5-, and 6-positions are not essential for the catalytic reaction of the enzyme leading to the broad substrate specificity of PcDTE. They also showed that the epimerization site of 1-deoxy 3-keto D-galactitol is shifted from C3 to C4 and that 1-deoxy sugars may bind to the catalytic site in the inhibitor-binding mode. The hydrophobic groove that acts as an accessible surface for substrate binding is formed through the dimerization of PcDTE. In PcDTE_C66S/deoxy sugar complex structures, bound ligand molecules in both the linear and ring forms were detected in the hydrophobic groove, while bound ligand molecules in the catalytic site were in the linear form. This result suggests that the sugar-ring opening of a substrate may occur in the hydrophobic groove and also that the narrow channel of the passageway to the catalytic site allows a substrate in the linear form to pass through.

X-ray structures of the Pseudomonas cichorii D-tagatose 3-epimerase mutant form C66S recognizing deoxy sugars as substrates.,Yoshida H, Yoshihara A, Ishii T, Izumori K, Kamitori S Appl Microbiol Biotechnol. 2016 Dec;100(24):10403-10415. doi:, 10.1007/s00253-016-7673-7. Epub 2016 Jul 1. PMID:27368739<ref>PMID:27368739</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xsm" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas cichorii]]
[[Category: Ishii T]]
[[Category: Izumori K]]
[[Category: Kamitori S]]
[[Category: Yoshida H]]
[[Category: Yoshihara A]]