Gate movements in glutamate transporters.

Sodium-coupled glutamate transporters are essential for efficient excitatory transmission in the brain and function by exposing their binding sites alternately to either the synapse or the interior of the cell. After the recent determination of the crystal structure of an archaeal homologue of the eukaryotic glutamate transporters, corresponding to the substrate occluded form, now the same has been achieved for the outward-facing conformation. These structures provide important insights into the molecular mechanism of ion-coupled transporters.