View source for 1uiu


==Crystal structures of the liganded and unliganded nickel binding protein NikA from Escherichia coli (Nickel unliganded form)==
<StructureSection load='1uiu' size='340' side='right'caption='[[1uiu]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1uiu]] 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=1UIU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1UIU 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]] 1.85&#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=1uiu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1uiu OCA], [https://pdbe.org/1uiu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1uiu RCSB], [https://www.ebi.ac.uk/pdbsum/1uiu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1uiu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NIKA_ECOLI NIKA_ECOLI] Involved in a nickel transport system, probably represents the nickel binder.
== 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/ui/1uiu_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=1uiu ConSurf].
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== Publication Abstract from PubMed ==
Bacteria have evolved a number of tightly controlled import and export systems to maintain intracellular levels of the essential but potentially toxic metal nickel. Nickel homeostasis systems include the dedicated nickel uptake system nik found in Escherichia coli, a member of the ABC family of transporters, that involves a periplasmic nickel-binding protein, NikA. This is the initial nickel receptor and mediator of the chemotactic response away from nickel. We have solved the crystal structure of NikA protein in the presence and absence of nickel, showing that it behaves as a "classical" periplasmic binding protein. In contrast to other binding proteins, however, the ligand remains accessible to the solvent and is not completely enclosed. No direct bonds are formed between the metal cation and the protein. The nickel binding site is apolar, quite unlike any previously characterized protein nickel binding site. Despite relatively weak binding, NikA is specific for nickel. Using isothermal titration calorimetry, the dissociation constant for nickel was found to be approximately 10 microm and that for cobalt was approximately 20 times higher.

Crystal structures of the liganded and unliganded nickel-binding protein NikA from Escherichia coli.,Heddle J, Scott DJ, Unzai S, Park SY, Tame JR J Biol Chem. 2003 Dec 12;278(50):50322-9. Epub 2003 Sep 5. PMID:12960164<ref>PMID:12960164</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 1uiu" style="background-color:#fffaf0;"></div>

==See Also==
*[[ABC transporter 3D structures|ABC transporter 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Heddle J]]
[[Category: Park S-Y]]
[[Category: Scott DJ]]
[[Category: Tame JRH]]
[[Category: Unzai S]]