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-Structure paper
Title | Structural ensemble of a glutamate transporter homologue in lipid nanodisc environment. |
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Journal, issue, pages | Nat Commun, Vol. 11, Issue 1, Page 998, Year 2020 |
Publish date | Feb 21, 2020 |
Authors | Valentina Arkhipova / Albert Guskov / Dirk J Slotboom / |
PubMed Abstract | Glutamate transporters are cation-coupled secondary active membrane transporters that clear the neurotransmitter L-glutamate from the synaptic cleft. These transporters are homotrimers, with each ...Glutamate transporters are cation-coupled secondary active membrane transporters that clear the neurotransmitter L-glutamate from the synaptic cleft. These transporters are homotrimers, with each protomer functioning independently by an elevator-type mechanism, in which a mobile transport domain alternates between inward- and outward-oriented states. Using single-particle cryo-EM we have determined five structures of the glutamate transporter homologue Glt, a Na- L-aspartate symporter, embedded in lipid nanodiscs. Dependent on the substrate concentrations used, the protomers of the trimer adopt a variety of asymmetrical conformations, consistent with the independent movement. Six of the 15 resolved protomers are in a hitherto elusive state of the transport cycle in which the inward-facing transporters are loaded with Na ions. These structures explain how substrate-leakage is prevented - a strict requirement for coupled transport. The belt protein of the lipid nanodiscs bends around the inward oriented protomers, suggesting that membrane deformations occur during transport. |
External links | Nat Commun / PubMed:32081874 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.22 - 3.47 Å |
Structure data | EMDB-10632, PDB-6xwn: EMDB-10633, PDB-6xwo: EMDB-10634, PDB-6xwp: EMDB-10635, PDB-6xwq: EMDB-10636, PDB-6xwr: |
Chemicals | ChemComp-TB1: ChemComp-ASP: |
Source |
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Keywords | TRANSPORT PROTEIN / AMINO ACID TRANSPORTER / ASPARTATE TRANSPORT / GLUTAMATE TRANSPORTER HOMOLOGUE / MEMBRANE PROTEIN |