View source for 1bq1


==E. COLI THYMIDYLATE SYNTHASE MUTANT N177A IN COMPLEX WITH CB3717 AND 2'-DEOXYURIDINE 5'-MONOPHOSPHATE (DUMP)==
<StructureSection load='1bq1' size='340' side='right'caption='[[1bq1]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1bq1]] 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=1BQ1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BQ1 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CB3:10-PROPARGYL-5,8-DIDEAZAFOLIC+ACID'>CB3</scene>, <scene name='pdbligand=CXM:N-CARBOXYMETHIONINE'>CXM</scene>, <scene name='pdbligand=UMP:2-DEOXYURIDINE+5-MONOPHOSPHATE'>UMP</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=1bq1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bq1 OCA], [https://pdbe.org/1bq1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bq1 RCSB], [https://www.ebi.ac.uk/pdbsum/1bq1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bq1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TYSY_ECOLI TYSY_ECOLI] Provides the sole de novo source of dTMP for DNA biosynthesis. This protein also binds to its mRNA thus repressing its own translation.
== 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/bq/1bq1_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1bq1 ConSurf].
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== Publication Abstract from PubMed ==
Mutation of thymidylate synthase N229(177) to alanine results in an essentially inactive enzyme, yet it leads to formation of a stable ternary complex. The kinetics of N229(177)A show that kcat for Escherichia coli is reduced by 200-fold while the Km for dUMP is increased 200-fold and the Km for folate increased by tenfold versus the wild-type enzyme. The crystal structures of N229(177)A in complex with dUMP and CB3717, and in complex with dUMP alone are determined at 2.4 A, and 2.5 A resolution. These structures identify the covalently bound ternary complex and show how N229(177)A traps an intermediate, and so becomes inactive in a later step of the reaction. Since the smaller alanine side-chain at N229(177)A does not directly sterically impair binding of ligands, the structures implicate, and place quantitative limits on the involvement of the structured water network in the active site of thymidylate synthase in both catalysis and in determining the binding affinity for dUMP (in contrast, the N229(177)V mutation in Lactobacillus casei has minimal effect on activity).

Inactivity of N229A thymidylate synthase due to water-mediated effects: isolating a late stage in methyl transfer.,Reyes CL, Sage CR, Rutenber EE, Nissen RM, Finer-Moore JS, Stroud RM J Mol Biol. 1998 Dec 4;284(3):699-712. PMID:9826509<ref>PMID:9826509</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 1bq1" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thymidylate synthase 3D structures|Thymidylate synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Finer-Moore JS]]
[[Category: Reyes CL]]
[[Category: Rutenber EE]]
[[Category: Sage CR]]
[[Category: Stroud RM]]