4P6H

Tl+-bound inward-facing state (bound conformation) of the glutamate transporter homologue GltPh

Summary for 4P6H

• Entry DOI: 10.2210/pdb4p6h/pdb
• Related: 1XFH 2NWL 2NWW 2NWX 3KBC 3V8F 3V8G 4IZM
• Descriptor: GltPh, MERCURY (II) ION, THALLIUM (I) ION (3 entities in total)
• Functional Keywords: transport protein
• Biological source: Pyrococcus horikoshii
• Total number of polymer chains: 3
• Total formula weight: 135675.80

Authors

Verdon, G.,Boudker, O. (deposition date: 2014-03-24, release date: 2014-06-04, Last modification date: 2023-12-20)

Primary citation

Verdon, G.,Oh, S.,Serio, R.N.,Boudker, O.
Coupled ion binding and structural transitions along the transport cycle of glutamate transporters.
Elife, 3:e02283-e02283, 2014

PubMed Abstract: 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.DOI: http://dx.doi.org/10.7554/eLife.02283.001.

PubMed: 24842876
DOI: 10.7554/eLife.02283

Experimental method

X-RAY DIFFRACTION (4.08 Å)