View source for 5xtx


==Crystal Structure of Transketolase in complex with TPP intermediate VII from Pichia Stipitis==
<StructureSection load='5xtx' size='340' side='right'caption='[[5xtx]], [[Resolution|resolution]] 1.05&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5xtx]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Scheffersomyces_stipitis_CBS_6054 Scheffersomyces stipitis CBS 6054]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5XTX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5XTX 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]] 1.049&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=8ML:2-[3-[(4-azanyl-2-methyl-pyrimidin-5-yl)methyl]-4-methylidene-2-[(2S,3S,4R,5R)-1,2,3,4,5-pentakis(oxidanyl)-6-phosphonooxy-hexan-2-yl]-1,3-thiazolidin-5-yl]ethyl+phosphono+hydrogen+phosphate'>8ML</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</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=5xtx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5xtx OCA], [https://pdbe.org/5xtx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5xtx RCSB], [https://www.ebi.ac.uk/pdbsum/5xtx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5xtx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TKT_PICST TKT_PICST] Catalyzes the transfer of a two-carbon ketol group from a ketose donor to an aldose acceptor, via a covalent intermediate with the cofactor thiamine pyrophosphate.
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== Publication Abstract from PubMed ==
Transketolase (TK) catalyzes a reversible transfer of a two-carbon (C2 ) unit between phosphoketose donors and phosphoaldose acceptors, for which the group-transfer reaction that follows a one- or two-electron mechanism and the force that breaks the C2"-C3" bond of the ketose donors remain unresolved. Herein, we report ultrahigh-resolution crystal structures of a TK (TKps) from Pichia stipitis in previously undiscovered intermediate states and support a diradical mechanism for a reversible group-transfer reaction. In conjunction with MS, NMR spectroscopy, EPR and computational analyses, it is concluded that the enzyme-catalyzed non-Kekule diradical cofactor brings about the C2"-C3" bond cleavage/formation for the C2 -unit transfer reaction, for which suppression of activation energy and activation and destabilization of enzymatic intermediates are facilitated.

Evidence of Diradicals Involved in the Yeast Transketolase Catalyzed Keto-Transferring Reactions.,Hsu NS, Wang YL, Lin KH, Chang CF, Ke SC, Lyu SY, Hsu LJ, Li YS, Chen SC, Wang KC, Li TL Chembiochem. 2018 Nov 16;19(22):2395-2402. doi: 10.1002/cbic.201800378. Epub 2018, Oct 18. PMID:30155962<ref>PMID:30155962</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5xtx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Transketolase 3D structures|Transketolase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Scheffersomyces stipitis CBS 6054]]
[[Category: Hsu NS]]
[[Category: Li TL]]
[[Category: Wang YL]]