4IZM

Crystal structure of GltPh L66C-S300C mutant crosslinked with divalent mercury

Summary for 4IZM

• Entry DOI: 10.2210/pdb4izm/pdb
• Related: 2NWL 2NWW 2NWX 3KBC 3V8F 3V8G
• Descriptor: 425aa long hypothetical proton glutamate symport protein, SODIUM ION, ASPARTIC ACID, ... (4 entities in total)
• Functional Keywords: amino acid transport system x-ag, biological transport, structure-activity relationship, transport protein
• Biological source: Pyrococcus horikoshii
• Cellular location: Cell membrane {ECO:0000305|PubMed:15483603, ECO:0000305|PubMed:17230192, ECO:0000305|PubMed:17435767, ECO:0000305|PubMed:19380583, ECO:0000305|PubMed:28137870, ECO:0000305|Ref: O59010
• Total number of polymer chains: 3
• Total formula weight: 134515.22

Authors

Reyes, N.,Boudker, O. (deposition date: 2013-01-30, release date: 2013-04-10, Last modification date: 2024-02-28)

Primary citation

Reyes, N.,Oh, S.,Boudker, O.
Binding thermodynamics of a glutamate transporter homolog.
Nat.Struct.Mol.Biol., 20:634-640, 2013

PubMed Abstract: 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.

PubMed: 23563139
DOI: 10.1038/nsmb.2548

Experimental method

X-RAY DIFFRACTION (4.5 Å)