View source for 1qul


==PHOSPHATE-BINDING PROTEIN MUTANT WITH ASP 137 REPLACED BY THR COMPLEX WITH CHLORINE AND PHOSPHATE==
<StructureSection load='1qul' size='340' side='right'caption='[[1qul]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qul]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QUL OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1QUL FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></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=1qul FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qul OCA], [http://pdbe.org/1qul PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1qul RCSB], [http://www.ebi.ac.uk/pdbsum/1qul PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1qul ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/PSTS_ECOLI PSTS_ECOLI]] Part of the ABC transporter complex PstSACB involved in phosphate import. 
== 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/qu/1qul_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=1qul ConSurf].
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== Publication Abstract from PubMed ==
Electrostatic interactions are among the key forces determining the structure and function of proteins. These are exemplified in the liganded form of the receptor, a phosphate binding protein from Escherichia coli. The phosphate, completely dehydrated and buried in the receptor, is bound by 12 hydrogen bonds as well as a salt link with Arg 135. We have modulated the ionic attraction while preserving the hydrogen bonds by mutating Asp 137, also salt linked to Arg 135, to Asn, Gly or Thr. High-resolution crystallographic analysis revealed that Gly and Thr (but not Asn) mutant proteins have incorporated a more electronegative Cl- in place of the Asp carboxylate. That no dramatic effect on phosphate affinity was produced by these ionic perturbations indicates a major role for hydrogen bonds and other local dipoles in the binding and charge stabilization of ionic ligands.

Modulation of a salt link does not affect binding of phosphate to its specific active transport receptor.,Yao N, Ledvina PS, Choudhary A, Quiocho FA Biochemistry. 1996 Feb 20;35(7):2079-85. PMID:8652549<ref>PMID:8652549</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 1qul" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phosphate-binding protein|Phosphate-binding protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus coli migula 1895]]
[[Category: Large Structures]]
[[Category: Choudhary, A]]
[[Category: Ledvina, P S]]
[[Category: Quiocho, F A]]
[[Category: Yao, N]]
[[Category: Binding protein]]
[[Category: Phosphate transport]]