A conserved aspartate residue located at the extracellular end of the binding pocket controls cation interactions in brain glutamate transporters.

ABSTRACT: In the brain, transporters of the major excitatory neurotransmitter glutamate remove their substrate from the synaptic cleft to allow optimal glutamatergic neurotransmission. Their transport cycle consists of two sequential translocation steps, namely cotransport of glutamic acid with three Na(+) ions, followed by countertransport of K(+). Recent studies, based on several crystal structures of the archeal homologue Glt(Ph), indicate that glutamate translocation occurs by an elevator-like mechanism. The resolution of these structures was not sufficiently high to unambiguously identify the sites of Na(+) binding, but functional and computational studies suggest some candidate sites. In the Glt(Ph) structure, a conserved aspartate residue (Asp-390) is located adjacent to a conserved tyrosine

SUBMITTER: Rosental N 

PROVIDER: S-EPMC3308850 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature