4p6h: Difference between revisions
New page: '''Unreleased structure''' The entry 4p6h is ON HOLD Authors: Verdon, G, Boudker, O Description: Tl+-bound inward-facing state (bound conformation) of the glutamate transporter homolog... |
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==Tl+-bound inward-facing state (bound conformation) of the glutamate transporter homologue GltPh== | |||
<StructureSection load='4p6h' size='340' side='right'caption='[[4p6h]], [[Resolution|resolution]] 4.08Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4p6h]] 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=4P6H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4P6H 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]] 4.08Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HG:MERCURY+(II)+ION'>HG</scene>, <scene name='pdbligand=TL:THALLIUM+(I)+ION'>TL</scene></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=4p6h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4p6h OCA], [https://pdbe.org/4p6h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4p6h RCSB], [https://www.ebi.ac.uk/pdbsum/4p6h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4p6h ProSAT]</span></td></tr> | |||
</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;"> | |||
== Publication Abstract from PubMed == | |||
Membrane transporters that clear the neurotransmitter glutamate from synapses are driven by symport of sodium ions and counter-transport of a potassium ion. Previous crystal structures of a homologous archaeal sodium and aspartate symporter showed that a dedicated transport domain carries the substrate and ions across the membrane. Here, we report new crystal structures of this homologue in ligand-free and ions-only bound outward- and inward-facing conformations. We show that after ligand release, the apo transport domain adopts a compact and occluded conformation that can traverse the membrane, completing the transport cycle. Sodium binding primes the transport domain to accept its substrate and triggers extracellular gate opening, which prevents inward domain translocation until substrate binding takes place. Furthermore, we describe a new cation-binding site ideally suited to bind a counter-transported ion. We suggest that potassium binding at this site stabilizes the translocation-competent conformation of the unloaded transport domain in mammalian homologues. | |||
Coupled ion binding and structural transitions along the transport cycle of glutamate transporters.,Verdon G, Oh S, Serio RN, Boudker O Elife. 2014 May 19:e02283. doi: 10.7554/eLife.02283. PMID:24842876<ref>PMID:24842876</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4p6h" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Symporter 3D structures|Symporter 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pyrococcus horikoshii OT3]] | |||
[[Category: Boudker O]] | |||
[[Category: Verdon G]] | |||
Latest revision as of 15:22, 20 December 2023
Tl+-bound inward-facing state (bound conformation) of the glutamate transporter homologue GltPhTl+-bound inward-facing state (bound conformation) of the glutamate transporter homologue GltPh
Structural highlights
FunctionGLT_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 PubMedMembrane transporters that clear the neurotransmitter glutamate from synapses are driven by symport of sodium ions and counter-transport of a potassium ion. Previous crystal structures of a homologous archaeal sodium and aspartate symporter showed that a dedicated transport domain carries the substrate and ions across the membrane. Here, we report new crystal structures of this homologue in ligand-free and ions-only bound outward- and inward-facing conformations. We show that after ligand release, the apo transport domain adopts a compact and occluded conformation that can traverse the membrane, completing the transport cycle. Sodium binding primes the transport domain to accept its substrate and triggers extracellular gate opening, which prevents inward domain translocation until substrate binding takes place. Furthermore, we describe a new cation-binding site ideally suited to bind a counter-transported ion. We suggest that potassium binding at this site stabilizes the translocation-competent conformation of the unloaded transport domain in mammalian homologues. Coupled ion binding and structural transitions along the transport cycle of glutamate transporters.,Verdon G, Oh S, Serio RN, Boudker O Elife. 2014 May 19:e02283. doi: 10.7554/eLife.02283. PMID:24842876[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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