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| [[Image:1ngs.gif|left|200px]]
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| <!-- | | ==COMPLEX OF TRANSKETOLASE WITH THIAMIN DIPHOSPHATE, CA2+ AND ACCEPTOR SUBSTRATE ERYTHROSE-4-PHOSPHATE== |
| The line below this paragraph, containing "STRUCTURE_1ngs", creates the "Structure Box" on the page.
| | <StructureSection load='1ngs' size='340' side='right'caption='[[1ngs]], [[Resolution|resolution]] 2.40Å' scene=''> |
| You may change the PDB parameter (which sets the PDB file loaded into the applet)
| | == Structural highlights == |
| or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
| | <table><tr><td colspan='2'>[[1ngs]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NGS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NGS FirstGlance]. <br> |
| or leave the SCENE parameter empty for the default display.
| | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4Å</td></tr> |
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| | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=E4P:ERYTHOSE-4-PHOSPHATE'>E4P</scene>, <scene name='pdbligand=TPP:THIAMINE+DIPHOSPHATE'>TPP</scene></td></tr> |
| {{STRUCTURE_1ngs| PDB=1ngs | SCENE= }}
| | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ngs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ngs OCA], [https://pdbe.org/1ngs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ngs RCSB], [https://www.ebi.ac.uk/pdbsum/1ngs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ngs ProSAT]</span></td></tr> |
| | </table> |
| | == Function == |
| | [https://www.uniprot.org/uniprot/TKT1_YEAST TKT1_YEAST] 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.<ref>PMID:8521838</ref> |
| | == 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/ng/1ngs_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1ngs ConSurf]. |
| | <div style="clear:both"></div> |
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| '''COMPLEX OF TRANSKETOLASE WITH THIAMIN DIPHOSPHATE, CA2+ AND ACCEPTOR SUBSTRATE ERYTHROSE-4-PHOSPHATE'''
| | ==See Also== |
| | | *[[Transketolase 3D structures|Transketolase 3D structures]] |
| | | == References == |
| ==Overview== | | <references/> |
| The three-dimensional structure of the quaternary complex of Saccharomyces cerevisiae transketolase, thiamin diphosphate, Ca2+, and the acceptor substrate erythrose-4-phosphate has been determined to 2.4 A resolution by protein crystallographic methods. Erythrose-4-phosphate was generated by enzymatic cleavage of fructose-6-phosphate. The overall structure of the enzyme in the quaternary complex is very similar to the structure of the holoenzyme; no large conformational changes upon substrate binding were found. The substrate binds in a deep cleft between the two subunits. The phosphate group of the substrate interacts with the side chains of the conserved residues Arg359, Arg528, His469, and Ser386 at the entrance of this cleft. The aldehyde moiety of the sugar phosphate is located in the vicinity of the C-2 carbon atom of the thiazolium ring of the cofactor. The aldehyde oxygen forms hydrogen bonds to the side chains of the residues His30 and His263. One of the hydroxyl groups of the sugar phosphate forms a hydrogen bond to the side chain of Asp477. The preference of the enzyme for donor substrates with D-threo configuration at the C-3 and C-4 positions and for alpha-hydroxylated acceptor substrates can be understood from the pattern of hydrogen bonds between enzyme and substrate. Amino acid replacements by site-directed mutagenesis of residues Arg359, Arg528, and His469 at the phosphate binding site yield mutant enzymes with considerable residual catalytic activity but increased Km values for the donor and in particular acceptor substrate, consistent with a role for these residues in phosphate binding. Replacement of Asp477 by alanine results in a mutant enzyme impaired in catalytic activity and with increased Km values for donor and acceptor substrates. These findings suggest a role for this amino acid in substrate binding and catalysis.
| | __TOC__ |
| | | </StructureSection> |
| ==About this Structure== | | [[Category: Large Structures]] |
| 1NGS is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NGS OCA].
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| ==Reference==
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| Examination of substrate binding in thiamin diphosphate-dependent transketolase by protein crystallography and site-directed mutagenesis., Nilsson U, Meshalkina L, Lindqvist Y, Schneider G, J Biol Chem. 1997 Jan 17;272(3):1864-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8999873 8999873]
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| [[Category: Saccharomyces cerevisiae]] | | [[Category: Saccharomyces cerevisiae]] |
| [[Category: Single protein]]
| | [[Category: Lindqvist Y]] |
| [[Category: Transketolase]]
| | [[Category: Nilsson U]] |
| [[Category: Lindqvist, Y.]] | | [[Category: Schneider G]] |
| [[Category: Nilsson, U.]] | |
| [[Category: Schneider, G.]] | |
| [[Category: Magnesium]]
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| [[Category: Multigene family]]
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| [[Category: Thiamine pyrophosphate]]
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| [[Category: Transferase]]
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| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 02:30:50 2008''
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