View source for 2rf1


==Crystal structure of ChoX in an unliganded closed conformation==
<StructureSection load='2rf1' size='340' side='right'caption='[[2rf1]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2rf1]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2RF1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2RF1 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&#8491;</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=2rf1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2rf1 OCA], [https://pdbe.org/2rf1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2rf1 RCSB], [https://www.ebi.ac.uk/pdbsum/2rf1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2rf1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q92N37_RHIME Q92N37_RHIME] 
== 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/rf/2rf1_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=2rf1 ConSurf].
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== Publication Abstract from PubMed ==
The ATP-binding cassette transporter ChoVWX is one of several choline import systems operating in Sinorhizobium meliloti. Here fluorescence-based ligand binding assays were used to quantitate substrate binding by the periplasmic ligand-binding protein ChoX. These data confirmed that ChoX recognizes choline and acetylcholine with high and medium affinity, respectively. We also report the crystal structures of ChoX in complex with either choline or acetylcholine. These structural investigations revealed an architecture of the ChoX binding pocket and mode of substrate binding similar to that reported previously for several compatible solute-binding proteins. Additionally the ChoX-acetylcholine complex permitted a detailed structural comparison with the carbamylcholine-binding site of the acetylcholine-binding protein from the mollusc Lymnaea stagnalis. In addition to the two liganded structures of ChoX, we were also able to solve the crystal structure of ChoX in a closed, substrate-free conformation that revealed an architecture of the ligand-binding site that is superimposable to the closed, ligand-bound form of ChoX. This structure is only the second of its kind and raises the important question of how ATP-binding cassette transporters are capable of distinguishing liganded and unliganded-closed states of the binding protein.

Crystal structures of the choline/acetylcholine substrate-binding protein ChoX from Sinorhizobium meliloti in the liganded and unliganded-closed states.,Oswald C, Smits SH, Hoing M, Sohn-Bosser L, Dupont L, Le Rudulier D, Schmitt L, Bremer E J Biol Chem. 2008 Nov 21;283(47):32848-59. Epub 2008 Sep 8. PMID:18779321<ref>PMID:18779321</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 2rf1" style="background-color:#fffaf0;"></div>

==See Also==
*[[ABC transporter 3D structures|ABC transporter 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Sinorhizobium meliloti]]
[[Category: Bremer E]]
[[Category: Hoeing M]]
[[Category: Le Rudulier D]]
[[Category: Oswald C]]
[[Category: Schmitt L]]
[[Category: Smits SHJ]]
[[Category: Sohn-Boeser L]]