View source for 2d4u


==Crystal Structure of the ligand binding domain of the bacterial serine chemoreceptor Tsr==
<StructureSection load='2d4u' size='340' side='right'caption='[[2d4u]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2d4u]] 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=2D4U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2D4U 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]] 1.95&#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=2d4u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2d4u OCA], [https://pdbe.org/2d4u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2d4u RCSB], [https://www.ebi.ac.uk/pdbsum/2d4u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2d4u ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MCP1_ECOLI MCP1_ECOLI] Receptor for the attractant L-serine and related amino acids. Is also responsible for chemotaxis away from a wide range of repellents, including leucine, indole, and weak acids.  Chemotactic-signal transducers respond to changes in the concentration of attractants and repellents in the environment, transduce a signal from the outside to the inside of the cell, and facilitate sensory adaptation through the variation of the level of methylation. Attractants increase the level of methylation while repellents decrease the level of methylation, the methyl groups are added by the methyltransferase CheR and removed by the methylesterase CheB.
== 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/d4/2d4u_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=2d4u ConSurf].
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== Publication Abstract from PubMed ==
Escherichia coli has closely related amino acid chemoreceptors with distinct ligand specificity: Tar for L-aspartate and Tsr for L-serine. Crystallography of the ligand-binding domain of Tar identified the residues interacting with aspartate, most of which are conserved in Tsr. However, swapping of the non-conserved residues between Tsr and Tar did not change ligand specificity. Analyses with chimeric receptors led us to hypothesize that distinct three-dimensional arrangements of the conserved ligand-binding residues are responsible for ligand specificity. To test this hypothesis, the structures of the apo and serine-binding forms of the ligand-binding domain of Tsr were determined at 1.95 and 2.5 A resolutions, respectively. Some of the Tsr residues are arranged differently from the corresponding aspartate-binding residues of Tar to form a high-affinity serine-binding pocket. The ligand-binding pocket of Tsr was surrounded by negatively charged residues, which presumably exclude negatively charged aspartate molecules. We propose that all these Tsr- and Tar-specific features contribute to specific recognition of serine and aspartate with the arrangement of the side chain of residue 68 (Asn in Tsr and Ser in Tar) being most critical.

Ligand specificity determined by differentially arranged common ligand-binding residues in the bacterial amino acid chemoreceptors Tsr and Tar.,Tajima H, Imada K, Sakuma M, Hattori F, Nara T, Kamo N, Homma M, Kawagishi I J Biol Chem. 2011 Oct 6. PMID:21979954<ref>PMID:21979954</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 2d4u" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chemotaxis protein 3D structures|Chemotaxis protein 3D structures]]
*[[Methyl-accepting chemotaxis protein|Methyl-accepting chemotaxis protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Homma M]]
[[Category: Imada K]]
[[Category: Kawagishi I]]
[[Category: Namba K]]
[[Category: Sakuma M]]
[[Category: Tajima H]]