View source for 3clb


==Structure of bifunctional TcDHFR-TS in complex with TMQ==
<StructureSection load='3clb' size='340' side='right' caption='[[3clb]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3clb]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Trycr Trycr]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CLB OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3CLB FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=TMQ:TRIMETREXATE'>TMQ</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2h2q|2h2q]], [[3cl9|3cl9]]</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3clb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3clb OCA], [http://pdbe.org/3clb PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3clb RCSB], [http://www.ebi.ac.uk/pdbsum/3clb PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3clb ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/DRTS_TRYCR DRTS_TRYCR]] Bifunctional enzyme. Involved in de novo dTMP biosynthesis. Key enzyme in folate metabolism. Catalyzes an essential reaction for de novo glycine and purine synthesis, DNA precursor synthesis, and for the conversion of dUMP to dTMP.[HAMAP-Rule:MF_00008] 
== 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/cl/3clb_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=3clb ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
We have employed a structure-based three-dimensional quantitative structure-activity relationship (3D-QSAR) approach to predict the biochemical activity for inhibitors of T. cruzi dihydrofolate reductase-thymidylate synthase (DHFR-TS). Crystal structures of complexes of the enzyme with eight different inhibitors of the DHFR activity together with the structure in the substrate-free state (DHFR domain) were used to validate and refine docking poses of ligands that constitute likely active conformations. Structural information from these complexes formed the basis for the structure-based alignment used as input for the QSAR study. Contrary to indirect ligand-based approaches the strategy described here employs a direct receptor-based approach. The goal is to generate a library of selective lead inhibitors for further development as antiparasitic agents. 3D-QSAR models were obtained for T. cruzi DHFR-TS (30 inhibitors in learning set) and human DHFR (36 inhibitors in learning set) that show a very good agreement between experimental and predicted enzyme inhibition data. For crossvalidation of the QSAR model(s), we have used the 10% leave-one-out method. The derived 3D-QSAR models were tested against a few selected compounds (a small test set of six inhibitors for each enzyme) with known activity, which were not part of the learning set, and the quality of prediction of the initial 3D-QSAR models demonstrated that such studies are feasible. Further refinement of the models through integration of additional activity data and optimization of reliable docking poses is expected to lead to an improved predictive ability.

Structure-based approach to pharmacophore identification, in silico screening, and three-dimensional quantitative structure-activity relationship studies for inhibitors of Trypanosoma cruzi dihydrofolate reductase function.,Schormann N, Senkovich O, Walker K, Wright DL, Anderson AC, Rosowsky A, Ananthan S, Shinkre B, Velu S, Chattopadhyay D Proteins. 2008 Dec;73(4):889-901. PMID:18536013<ref>PMID:18536013</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 3clb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Dihydrofolate reductase|Dihydrofolate reductase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Trycr]]
[[Category: Chattopadhyay, D]]
[[Category: Schormann, N]]
[[Category: Senkovich, O]]
[[Category: Bifunctional enzyme in complex with nadp and tmq]]
[[Category: Oxidoreductase]]
[[Category: Oxidoreductase-transferase complex]]
[[Category: Transferase]]