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| - | [[Image:2ht3.gif|left|200px]] | |
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| - | <!-- | + | ==Structure of the Escherichia coli ClC chloride channel Y445L mutant and Fab complex== |
| - | The line below this paragraph, containing "STRUCTURE_2ht3", creates the "Structure Box" on the page.
| + | <StructureSection load='2ht3' size='340' side='right'caption='[[2ht3]], [[Resolution|resolution]] 3.30Å' scene=''> |
| - | You may change the PDB parameter (which sets the PDB file loaded into the applet) | + | == Structural highlights == |
| - | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | + | <table><tr><td colspan='2'>[[2ht3]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] 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=2HT3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HT3 FirstGlance]. <br> |
| - | or leave the SCENE parameter empty for the default display.
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.3Å</td></tr> |
| - | --> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BR:BROMIDE+ION'>BR</scene></td></tr> |
| - | {{STRUCTURE_2ht3| PDB=2ht3 | SCENE= }}
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2ht3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ht3 OCA], [https://pdbe.org/2ht3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ht3 RCSB], [https://www.ebi.ac.uk/pdbsum/2ht3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ht3 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> |
| | + | == 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/ht/2ht3_consurf.spt"</scriptWhenChecked> |
| | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2ht3 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | The Cl-/H+ exchange-transporter CLC-ec1 mediates stoichiometric transmembrane exchange of two Cl- ions for one proton. A conserved tyrosine residue, Y445, coordinates one of the bound Cl- ions visible in the structure of this protein and is located near the intersection of the Cl- and H+ pathways. Mutants of this tyrosine were scrutinized for effects on the coupled transport of Cl- and H+ determined electrophysiologically and on protein structure determined crystallographically. Despite the strong conservation of Y445 in the CLC family, substitution of F or W at this position preserves wild-type transport behavior. Substitution by A, E, or H, however, produces uncoupled proteins with robust Cl- transport but greatly impaired movement of H+. The obligatory 2 Cl-/1 H+ stoichiometry is thus lost in these mutants. The structures of all the mutants are essentially identical to wild-type, but apparent anion occupancy in the Cl- binding region correlates with functional H+ coupling. In particular, as determined by anomalous diffraction in crystals grown in Br-, an electrophysiologically competent Cl- analogue, the well-coupled transporters show strong Br- electron density at the "inner" and "central" Cl- binding sites. However, in the uncoupled mutants, Br- density is absent at the central site, while still present at the inner site. An additional mutant, Y445L, is intermediate in both functional and structural features. This mutant clearly exchanges H+ for Cl-, but at a reduced H+-to-Cl- ratio; likewise, both the central and inner sites are occupied by Br-, but the central site shows lower Br- density than in wild-type (or in Y445F,W). The correlation between proton coupling and central-site occupancy argues that halide binding to the central transport site somehow facilitates movement of H+, a synergism that is not readily understood in terms of alternating-site antiport schemes. |
| | | | |
| - | '''Structure of the Escherichia coli ClC chloride channel Y445L mutant and Fab complex'''
| + | Synergism between halide binding and proton transport in a CLC-type exchanger.,Accardi A, Lobet S, Williams C, Miller C, Dutzler R J Mol Biol. 2006 Sep 29;362(4):691-9. Epub 2006 Aug 2. PMID:16949616<ref>PMID:16949616</ref> |
| - | | + | |
| - | | + | |
| - | ==Overview==
| + | |
| - | The Cl-/H+ exchange-transporter CLC-ec1 mediates stoichiometric transmembrane exchange of two Cl- ions for one proton. A conserved tyrosine residue, Y445, coordinates one of the bound Cl- ions visible in the structure of this protein and is located near the intersection of the Cl- and H+ pathways. Mutants of this tyrosine were scrutinized for effects on the coupled transport of Cl- and H+ determined electrophysiologically and on protein structure determined crystallographically. Despite the strong conservation of Y445 in the CLC family, substitution of F or W at this position preserves wild-type transport behavior. Substitution by A, E, or H, however, produces uncoupled proteins with robust Cl- transport but greatly impaired movement of H+. The obligatory 2 Cl-/1 H+ stoichiometry is thus lost in these mutants. The structures of all the mutants are essentially identical to wild-type, but apparent anion occupancy in the Cl- binding region correlates with functional H+ coupling. In particular, as determined by anomalous diffraction in crystals grown in Br-, an electrophysiologically competent Cl- analogue, the well-coupled transporters show strong Br- electron density at the "inner" and "central" Cl- binding sites. However, in the uncoupled mutants, Br- density is absent at the central site, while still present at the inner site. An additional mutant, Y445L, is intermediate in both functional and structural features. This mutant clearly exchanges H+ for Cl-, but at a reduced H+-to-Cl- ratio; likewise, both the central and inner sites are occupied by Br-, but the central site shows lower Br- density than in wild-type (or in Y445F,W). The correlation between proton coupling and central-site occupancy argues that halide binding to the central transport site somehow facilitates movement of H+, a synergism that is not readily understood in terms of alternating-site antiport schemes.
| + | |
| | | | |
| - | ==About this Structure==
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | 2HT3 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HT3 OCA].
| + | </div> |
| | + | <div class="pdbe-citations 2ht3" style="background-color:#fffaf0;"></div> |
| | | | |
| - | ==Reference== | + | ==See Also== |
| - | Synergism between halide binding and proton transport in a CLC-type exchanger., Accardi A, Lobet S, Williams C, Miller C, Dutzler R, J Mol Biol. 2006 Sep 29;362(4):691-9. Epub 2006 Aug 2. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16949616 16949616]
| + | *[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]] |
| | + | == References == |
| | + | <references/> |
| | + | __TOC__ |
| | + | </StructureSection> |
| | [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Mus musculus]] | | [[Category: Mus musculus]] |
| - | [[Category: Single protein]]
| + | [[Category: Accardi A]] |
| - | [[Category: Accardi, A.]] | + | [[Category: Dutzler R]] |
| - | [[Category: Dutzler, R.]] | + | [[Category: Lobet S]] |
| - | [[Category: Lobet, S.]] | + | [[Category: Miller C]] |
| - | [[Category: Miller, C.]] | + | [[Category: Williams C]] |
| - | [[Category: Williams, C.]] | + | |
| - | [[Category: Clc family of channel and transporter]]
| + | |
| - | [[Category: Fab complex]]
| + | |
| - | [[Category: H+/cl- antiporter,membrane protein]]
| + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 06:40:29 2008''
| + | |
| 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 PubMed
The Cl-/H+ exchange-transporter CLC-ec1 mediates stoichiometric transmembrane exchange of two Cl- ions for one proton. A conserved tyrosine residue, Y445, coordinates one of the bound Cl- ions visible in the structure of this protein and is located near the intersection of the Cl- and H+ pathways. Mutants of this tyrosine were scrutinized for effects on the coupled transport of Cl- and H+ determined electrophysiologically and on protein structure determined crystallographically. Despite the strong conservation of Y445 in the CLC family, substitution of F or W at this position preserves wild-type transport behavior. Substitution by A, E, or H, however, produces uncoupled proteins with robust Cl- transport but greatly impaired movement of H+. The obligatory 2 Cl-/1 H+ stoichiometry is thus lost in these mutants. The structures of all the mutants are essentially identical to wild-type, but apparent anion occupancy in the Cl- binding region correlates with functional H+ coupling. In particular, as determined by anomalous diffraction in crystals grown in Br-, an electrophysiologically competent Cl- analogue, the well-coupled transporters show strong Br- electron density at the "inner" and "central" Cl- binding sites. However, in the uncoupled mutants, Br- density is absent at the central site, while still present at the inner site. An additional mutant, Y445L, is intermediate in both functional and structural features. This mutant clearly exchanges H+ for Cl-, but at a reduced H+-to-Cl- ratio; likewise, both the central and inner sites are occupied by Br-, but the central site shows lower Br- density than in wild-type (or in Y445F,W). The correlation between proton coupling and central-site occupancy argues that halide binding to the central transport site somehow facilitates movement of H+, a synergism that is not readily understood in terms of alternating-site antiport schemes.
Synergism between halide binding and proton transport in a CLC-type exchanger.,Accardi A, Lobet S, Williams C, Miller C, Dutzler R J Mol Biol. 2006 Sep 29;362(4):691-9. Epub 2006 Aug 2. PMID:16949616[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Iyer R, Iverson TM, Accardi A, Miller C. A biological role for prokaryotic ClC chloride channels. Nature. 2002 Oct 17;419(6908):715-8. PMID:12384697 doi:10.1038/nature01000
- ↑ Accardi A, Miller C. Secondary active transport mediated by a prokaryotic homologue of ClC Cl- channels. Nature. 2004 Feb 26;427(6977):803-7. PMID:14985752 doi:10.1038/nature02314
- ↑ Lobet S, Dutzler R. Ion-binding properties of the ClC chloride selectivity filter. EMBO J. 2006 Jan 11;25(1):24-33. Epub 2005 Dec 8. PMID:16341087
- ↑ Nguitragool W, Miller C. Uncoupling of a CLC Cl-/H+ exchange transporter by polyatomic anions. J Mol Biol. 2006 Sep 29;362(4):682-90. Epub 2006 Aug 14. PMID:16905147 doi:10.1016/j.jmb.2006.07.006
- ↑ Jayaram H, Accardi A, Wu F, Williams C, Miller C. Ion permeation through a Cl--selective channel designed from a CLC Cl-/H+ exchanger. Proc Natl Acad Sci U S A. 2008 Aug 12;105(32):11194-9. Epub 2008 Aug 4. PMID:18678918
- ↑ Accardi A, Lobet S, Williams C, Miller C, Dutzler R. Synergism between halide binding and proton transport in a CLC-type exchanger. J Mol Biol. 2006 Sep 29;362(4):691-9. Epub 2006 Aug 2. PMID:16949616 doi:10.1016/j.jmb.2006.07.081
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