View source for 3cwn


==Escherichia coli transaldolase b mutant f178y==
<StructureSection load='3cwn' size='340' side='right'caption='[[3cwn]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3cwn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CWN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3CWN 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]] 1.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=3cwn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3cwn OCA], [https://pdbe.org/3cwn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3cwn RCSB], [https://www.ebi.ac.uk/pdbsum/3cwn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3cwn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TALB_ECOLI TALB_ECOLI] Transaldolase is important for the balance of metabolites in the pentose-phosphate pathway.[HAMAP-Rule:MF_00492]
== 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/cw/3cwn_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=3cwn ConSurf].
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== Publication Abstract from PubMed ==
Based on a structure-assisted sequence alignment we designed 11 focused libraries at residues in the active site of transaldolase B from Escherichia coli and screened them for their ability to synthesize fructose 6-phosphate from dihydroxyacetone and glyceraldehyde 3-phosphate using a newly developed color assay. We found one positive variant exhibiting a replacement of Phe(178) to Tyr. This mutant variant is able not only to transfer a dihydroxyacetone moiety from a ketose donor, fructose 6-phosphate, onto an aldehyde acceptor, erythrose 4-phosphate (14 units/mg), but to use it as a substrate directly in an aldolase reaction (7 units/mg). With a single amino acid replacement the fructose-6-phosphate aldolase activity was increased considerably (&gt;70-fold compared with wild-type). Structural studies of the wild-type and mutant protein suggest that this is due to a different H-bond pattern in the active site leading to a destabilization of the Schiff base intermediate. Furthermore, we show that a homologous replacement has a similar effect in the human transaldolase Taldo1 (aldolase activity, 14 units/mg). We also demonstrate that both enzymes TalB and Taldo1 are recognized by the same polyclonal antibody.

Replacement of a phenylalanine by a tyrosine in the active site confers fructose-6-phosphate aldolase activity to the transaldolase of Escherichia coli and human origin.,Schneider S, Sandalova T, Schneider G, Sprenger GA, Samland AK J Biol Chem. 2008 Oct 31;283(44):30064-72. Epub 2008 Aug 7. PMID:18687684<ref>PMID:18687684</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3cwn" style="background-color:#fffaf0;"></div>

==See Also==
*[[Transaldolase 3D structures|Transaldolase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Samland A]]
[[Category: Sandalova T]]
[[Category: Schneider G]]