View source for 3ezi


==Crystal Structure of the E. coli Histidine Kinase NarX Sensor Domain without Ligand==
<StructureSection load='3ezi' size='340' side='right'caption='[[3ezi]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ezi]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3EZI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3EZI 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]] 1.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</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=3ezi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ezi OCA], [https://pdbe.org/3ezi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ezi RCSB], [https://www.ebi.ac.uk/pdbsum/3ezi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ezi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NARX_ECOLI NARX_ECOLI] Acts as a sensor for nitrate/nitrite and transduces signal of nitrate availability to the NarL protein and of both nitrate/nitrite to the NarP protein. NarX probably activates NarL and NarP by phosphorylation in the presence of nitrate. NarX also plays a negative role in controlling NarL activity, probably through dephosphorylation in the absence of nitrate.
== 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/ez/3ezi_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=3ezi ConSurf].
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== Publication Abstract from PubMed ==
Histidine kinase receptors are a large family of membrane-spanning proteins found in many prokaryotes and some eukaryotes. They are a part of two-component signal transduction systems, which each comprise a sensor kinase and a response regulator and are involved with the regulation of many cellular processes. NarX is a histidine kinase receptor that responds to nitrate and nitrite to effect regulation of anaerobic respiration in various bacteria. We present high-resolution X-ray crystal structures of the periplasmic sensor domain from Escherichia coli NarX in a complex with nitrate and in the apo state. Our analysis reveals that nitrate-binding induces conformation changes that result in a piston-type displacement between the N- and C-terminal helices of the periplasmic domain. Such conformational changes might represent a conserved mechanism of signaling in histidine kinases by which ligand binding is communicated across the lipid bilayer.

Structural Analysis of Ligand Stimulation of the Histidine Kinase NarX.,Cheung J, Hendrickson WA Structure. 2009 Feb 13;17(2):190-201. PMID:19217390<ref>PMID:19217390</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Cheung J]]
[[Category: Hendrickson WA]]