Evidence for a third sodium-binding site in glutamate transporters suggests an ion/substrate coupling model.

ABSTRACT: Excitatory amino acid transporters (EAATs) remove glutamate from synapses. They maintain an efficient synaptic transmission and prevent glutamate from reaching neurotoxic levels. Glutamate transporters couple the uptake of one glutamate to the cotransport of three sodium ions and one proton and the countertransport of one potassium ion. The molecular mechanism for this coupled uptake of glutamate and its co- and counter-transported ions is not known. In a crystal structure of the bacterial glutamate transporter homolog, GltPh, only two cations are bound to the transporter, and there is no indication of the location of the third sodium site. In experiments using voltage clamp fluorometry and simulations based on molecular dynamics combined with grand canonical Monte Carlo and free energy si

SUBMITTER: Larsson HP 

PROVIDER: S-EPMC2922246 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature