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4x2s

From Proteopedia

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Current revision

Crystal structure of 276S/M395R-GltPh in inward-facing conformation

Structural highlights

4x2s is a 3 chain structure with sequence from Pyrococcus horikoshii OT3. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 4.21Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

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 terminate neurotransmission by clearing synaptically released glutamate from the extracellular space, allowing repeated rounds of signalling and preventing glutamate-mediated excitotoxicity. Crystallographic studies of a glutamate transporter homologue from the archaeon Pyrococcus horikoshii, GltPh, showed that distinct transport domains translocate substrates into the cytoplasm by moving across the membrane within a central trimerization scaffold. Here we report direct observations of these 'elevator-like' transport domain motions in the context of reconstituted proteoliposomes and physiological ion gradients using single-molecule fluorescence resonance energy transfer (smFRET) imaging. We show that GltPh bearing two mutations introduced to impart characteristics of the human transporter exhibits markedly increased transport domain dynamics, which parallels an increased rate of substrate transport, thereby establishing a direct temporal relationship between transport domain motion and substrate uptake. Crystallographic and computational investigations corroborated these findings by revealing that the 'humanizing' mutations favour structurally 'unlocked' intermediate states in the transport cycle exhibiting increased solvent occupancy at the interface between the transport domain and the trimeric scaffold.

Transport domain unlocking sets the uptake rate of an aspartate transporter.,Akyuz N, Georgieva ER, Zhou Z, Stolzenberg S, Cuendet MA, Khelashvili G, Altman RB, Terry DS, Freed JH, Weinstein H, Boudker O, Blanchard SC Nature. 2015 Feb 5;518(7537):68-73. doi: 10.1038/nature14158. PMID:25652997^[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
↑ Akyuz N, Georgieva ER, Zhou Z, Stolzenberg S, Cuendet MA, Khelashvili G, Altman RB, Terry DS, Freed JH, Weinstein H, Boudker O, Blanchard SC. Transport domain unlocking sets the uptake rate of an aspartate transporter. Nature. 2015 Feb 5;518(7537):68-73. doi: 10.1038/nature14158. PMID:25652997 doi:http://dx.doi.org/10.1038/nature14158

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4x2s"

Categories: Large Structures | Pyrococcus horikoshii OT3 | Akyuz N | Boudker O

@@ Line 4: / Line 4: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[4x2s]] 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=4X2S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4X2S FirstGlance]. <br>
-</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=NA:SODIUM+ION'>NA</scene></td></tr>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 4.21&#8491;</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=NA:SODIUM+ION'>NA</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=4x2s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4x2s OCA], [https://pdbe.org/4x2s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4x2s RCSB], [https://www.ebi.ac.uk/pdbsum/4x2s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4x2s ProSAT]</span></td></tr>
 </table>

4x2s

From Proteopedia

Current revision

Crystal structure of 276S/M395R-GltPh in inward-facing conformation

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

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