2fee: Difference between revisions
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==Structure of the Cl-/H+ exchanger CLC-ec1 from E.Coli in NaBr== | ==Structure of the Cl-/H+ exchanger CLC-ec1 from E.Coli in NaBr== | ||
<StructureSection load='2fee' size='340' side='right' caption='[[2fee]], [[Resolution|resolution]] 3.20Å' scene=''> | <StructureSection load='2fee' size='340' side='right'caption='[[2fee]], [[Resolution|resolution]] 3.20Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2fee]] is a 6 chain structure with sequence from [ | <table><tr><td colspan='2'>[[2fee]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895] and [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FEE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2FEE FirstGlance]. <br> | ||
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ots|1ots]], [[2fec|2fec]], [[2fed|2fed]]</td></tr> | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ots|1ots]], [[2fec|2fec]], [[2fed|2fed]]</div></td></tr> | ||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">clcA, eriC ([ | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">clcA, eriC ([https://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'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2fee FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fee OCA], [https://pdbe.org/2fee PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2fee RCSB], [https://www.ebi.ac.uk/pdbsum/2fee PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2fee ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == 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> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
[[Image:Consurf_key_small.gif|200px|right]] | [[Image:Consurf_key_small.gif|200px|right]] | ||
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[[Category: Bacillus coli migula 1895]] | [[Category: Bacillus coli migula 1895]] | ||
[[Category: Human]] | [[Category: Human]] | ||
[[Category: Large Structures]] | |||
[[Category: Accardi, A]] | [[Category: Accardi, A]] | ||
[[Category: Jayaram, H]] | [[Category: Jayaram, H]] | ||
Revision as of 10:15, 24 February 2021
Structure of the Cl-/H+ exchanger CLC-ec1 from E.Coli in NaBrStructure of the Cl-/H+ exchanger CLC-ec1 from E.Coli in NaBr
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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