2fec: Difference between revisions
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==Structure of the E203Q mutant of the Cl-/H+ exchanger CLC-ec1 from E.Coli== | ==Structure of the E203Q mutant of the Cl-/H+ exchanger CLC-ec1 from E.Coli== | ||
<StructureSection load='2fec' size='340' side='right' caption='[[2fec]], [[Resolution|resolution]] 3.97Å' scene=''> | <StructureSection load='2fec' size='340' side='right' caption='[[2fec]], [[Resolution|resolution]] 3.97Å' scene=''> | ||
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</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ots|1ots]], [[2fed|2fed]], [[2fee|2fee]]</td></tr> | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ots|1ots]], [[2fed|2fed]], [[2fee|2fee]]</td></tr> | ||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">clcA, eriC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr> | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">clcA, eriC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2fec FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fec OCA], [http://pdbe.org/2fec PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2fec RCSB], [http://www.ebi.ac.uk/pdbsum/2fec PDBsum]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2fec FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fec OCA], [http://pdbe.org/2fec PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2fec RCSB], [http://www.ebi.ac.uk/pdbsum/2fec PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2fec ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
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Check<jmol> | Check<jmol> | ||
<jmolCheckbox> | <jmolCheckbox> | ||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fe/2fec_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/fe/2fec_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
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==See Also== | ==See Also== | ||
*[[Monoclonal | *[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
Revision as of 12:21, 14 June 2018
Structure of the E203Q mutant of the Cl-/H+ exchanger CLC-ec1 from E.ColiStructure of the E203Q mutant of the Cl-/H+ exchanger CLC-ec1 from E.Coli
Structural highlights
Function[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.[1] [2] [3] [4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCLC-ec1 is a prokaryotic CLC-type Cl(-)/H+ exchange transporter. Little is known about the mechanism of H+ coupling to Cl-. A critical glutamate residue, E148, was previously shown to be required for Cl(-)/H+ exchange by mediating proton transfer between the protein and the extracellular solution. To test whether an analogous H+ acceptor exists near the intracellular side of the protein, we performed a mutagenesis scan of inward-facing carboxyl-bearing residues and identified E203 as the unique residue whose neutralization abolishes H+ coupling to Cl- transport. Glutamate at this position is strictly conserved in all known CLCs of the transporter subclass, while valine is always found here in CLC channels. The x-ray crystal structure of the E203Q mutant is similar to that of the wild-type protein. Cl- transport rate in E203Q is inhibited at neutral pH, and the double mutant, E148A/E203Q, shows maximal Cl- transport, independent of pH, as does the single mutant E148A. The results argue that substrate exchange by CLC-ec1 involves two separate but partially overlapping permeation pathways, one for Cl- and one for H+. These pathways are congruent from the protein's extracellular surface to E148, and they diverge beyond this point toward the intracellular side. This picture demands a transport mechanism fundamentally different from familiar alternating-access schemes. Separate ion pathways in a Cl-/H+ exchanger.,Accardi A, Walden M, Nguitragool W, Jayaram H, Williams C, Miller C J Gen Physiol. 2005 Dec;126(6):563-70. PMID:16316975[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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