The structure of glutamate transporters shows channel-like features

Neuronal and glial glutamate transporters remove the excitatory neurotransm itter glutamate from the synaptic cleft and thus prevent neurotoxicity, The proteins belong to a large family of secondary transporters, which include s transporters from a variety of bacterial, archaeal and eukaryotic organis ms. The transporters consist of eight membrane-spanning alpha -helices and two pore-loop structures, which are unique among secondary transporters but may resemble pore-loops found in ion channels, Another distinctive structu ral feature is the presence of a highly amphipathic membrane-spanning alpha -helix that provides a hydrophilic path through the membrane. The unusual structural features of the transporters are discussed in relation to their function. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.