View source for 4kka


==Structure of the E148A mutant of CLC-ec1 deltaNC construct in 100mM fluoride and 20mM Bromide==
<StructureSection load='4kka' size='340' side='right'caption='[[4kka]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4kka]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KKA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KKA 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]] 3&#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=4kka FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kka OCA], [https://pdbe.org/4kka PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4kka RCSB], [https://www.ebi.ac.uk/pdbsum/4kka PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4kka ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CLCA_ECOLI CLCA_ECOLI] Proton-coupled chloride transporter. Functions as antiport system and exchanges two chloride ions for 1 proton. Probably acts as an electrical shunt for an outwardly-directed proton pump that is linked to amino acid decarboxylation, as part of the extreme acid resistance (XAR) response.<ref>PMID:12384697</ref> <ref>PMID:14985752</ref> <ref>PMID:16341087</ref> <ref>PMID:16905147</ref> <ref>PMID:18678918</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cl-/H+ antiporters of the CLC superfamily transport anions across biological membranes in varied physiological contexts. These proteins are weakly selective among anions commonly studied, including Cl-, Br-, I-, NO3- and SCN-, but they seem to be very selective against F-. The recent discovery of a new CLC clade of F-/H+ antiporters, which are highly selective for F- over Cl-, led us to investigate the mechanism of Cl--over-F- selectivity by a CLC Cl-/H+ antiporter, CLC-ec1. By subjecting purified CLC-ec1 to anion transport measurements, electrophysiological recording, equilibrium ligand-binding studies and X-ray crystallography, we show that F- binds in the Cl- transport pathway with affinity similar to Cl- but stalls the transport cycle. Examination of various mutant antiporters implies a 'lock-down' mechanism of F- inhibition, in which F-, by virtue of its unique hydrogen-bonding chemistry, greatly retards a proton-linked conformational change essential for the transport cycle of CLC-ec1.

Fluoride-dependent interruption of the transport cycle of a CLC Cl/H antiporter.,Lim HH, Stockbridge RB, Miller C Nat Chem Biol. 2013 Sep 15. doi: 10.1038/nchembio.1336. PMID:24036509<ref>PMID:24036509</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4kka" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Lim H-H]]
[[Category: Miller C]]