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| | ==Crystal structure of GltPh L66C-S300C mutant crosslinked with divalent mercury== | | ==Crystal structure of GltPh L66C-S300C mutant crosslinked with divalent mercury== |
| - | <StructureSection load='4izm' size='340' side='right' caption='[[4izm]], [[Resolution|resolution]] 4.50Å' scene=''> | + | <StructureSection load='4izm' size='340' side='right'caption='[[4izm]], [[Resolution|resolution]] 4.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4izm]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IZM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4IZM FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4izm]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_horikoshii_OT3 Pyrococcus horikoshii OT3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IZM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4IZM FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ASP:ASPARTIC+ACID'>ASP</scene>, <scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ASP:ASPARTIC+ACID'>ASP</scene>, <scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2nwl|2nwl]], [[2nww|2nww]], [[3v8f|3v8f]], [[3v8g|3v8g]], [[3kbc|3kbc]], [[2nwx|2nwx]]</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=4izm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4izm OCA], [https://pdbe.org/4izm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4izm RCSB], [https://www.ebi.ac.uk/pdbsum/4izm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4izm ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PH1295 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=70601 Pyrococcus horikoshii])</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=4izm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4izm OCA], [http://pdbe.org/4izm PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4izm RCSB], [http://www.ebi.ac.uk/pdbsum/4izm PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4izm ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/GLT_PYRHO GLT_PYRHO] Sodium-dependent, high-affinity amino acid transporter that mediates aspartate uptake (PubMed:17435767, PubMed:19380583, PubMed:17230192, Ref.11). Has only very low glutamate transport activity (PubMed:19380583, PubMed:17230192). Functions as a symporter that transports one amino acid molecule together with two or three Na(+) ions, resulting in electrogenic transport (PubMed:17435767, PubMed:19380583, Ref.11). Na(+) binding enhances the affinity for aspartate (PubMed:19380583, Ref.11). Mediates Cl(-) flux that is not coupled to amino acid transport; this avoids the accumulation of negative charges due to aspartate and Na(+) symport (PubMed:17435767). In contrast to mammalian homologs, transport does not depend on pH or K(+) ions (PubMed:19380583).<ref>PMID:17230192</ref> <ref>PMID:17435767</ref> <ref>PMID:19380583</ref> [PDB:4P19] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Pyrococcus horikoshii]] | + | [[Category: Large Structures]] |
| - | [[Category: Boudker, O]] | + | [[Category: Pyrococcus horikoshii OT3]] |
| - | [[Category: Reyes, N]] | + | [[Category: Boudker O]] |
| - | [[Category: Amino acid transport system x-ag]] | + | [[Category: Reyes N]] |
| - | [[Category: Biological transport]]
| + | |
| - | [[Category: Structure-activity relationship]]
| + | |
| - | [[Category: Transport protein]]
| + | |
| Structural highlights
Function
GLT_PYRHO Sodium-dependent, high-affinity amino acid transporter that mediates aspartate uptake (PubMed:17435767, PubMed:19380583, PubMed:17230192, Ref.11). Has only very low glutamate transport activity (PubMed:19380583, PubMed:17230192). Functions as a symporter that transports one amino acid molecule together with two or three Na(+) ions, resulting in electrogenic transport (PubMed:17435767, PubMed:19380583, Ref.11). Na(+) binding enhances the affinity for aspartate (PubMed:19380583, Ref.11). Mediates Cl(-) flux that is not coupled to amino acid transport; this avoids the accumulation of negative charges due to aspartate and Na(+) symport (PubMed:17435767). In contrast to mammalian homologs, transport does not depend on pH or K(+) ions (PubMed:19380583).[1] [2] [3] [PDB:4P19]
Publication Abstract from PubMed
Glutamate transporters catalyze concentrative uptake of the neurotransmitter into glial cells and neurons. Their transport cycle involves binding and release of the substrate on the extra- and intracellular sides of the plasma membranes and translocation of the substrate-binding site across the lipid bilayers. The energy of the ionic gradients, mainly sodium, fuels the cycle. Here, we used a cross-linking approach to trap a glutamate transporter homolog from Pyrococcus horikoshii in key conformational states with the substrate-binding site facing either the extracellular or the intracellular side of the membrane to study binding thermodynamics. We show that the chemical potential of sodium ions in solution is exclusively coupled to substrate binding and release, not to substrate translocation. Despite the transporter's structural symmetry, the binding mechanisms are distinct on the opposite sides of the membrane and more complex than the current models suggest.
Binding thermodynamics of a glutamate transporter homolog.,Reyes N, Oh S, Boudker O Nat Struct Mol Biol. 2013 May;20(5):634-40. doi: 10.1038/nsmb.2548. Epub 2013 Apr, 7. PMID:23563139[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Boudker O, Ryan RM, Yernool D, Shimamoto K, Gouaux E. Coupling substrate and ion binding to extracellular gate of a sodium-dependent aspartate transporter. Nature. 2007 Jan 25;445(7126):387-93. Epub 2007 Jan 17. PMID:17230192 doi:10.1038/nature05455
- ↑ Ryan RM, Mindell JA. The uncoupled chloride conductance of a bacterial glutamate transporter homolog. Nat Struct Mol Biol. 2007 May;14(5):365-71. doi: 10.1038/nsmb1230. Epub 2007 Apr , 15. PMID:17435767 doi:http://dx.doi.org/10.1038/nsmb1230
- ↑ Ryan RM, Compton EL, Mindell JA. Functional characterization of a Na+-dependent aspartate transporter from Pyrococcus horikoshii. J Biol Chem. 2009 Jun 26;284(26):17540-8. doi: 10.1074/jbc.M109.005926. Epub 2009, Apr 20. PMID:19380583 doi:http://dx.doi.org/10.1074/jbc.M109.005926
- ↑ Reyes N, Oh S, Boudker O. Binding thermodynamics of a glutamate transporter homolog. Nat Struct Mol Biol. 2013 May;20(5):634-40. doi: 10.1038/nsmb.2548. Epub 2013 Apr, 7. PMID:23563139 doi:10.1038/nsmb.2548
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