Molecular mechanism of ion-ion and ion-substrate coupling in the Na+-dependent leucine transporter LeuT.

ABSTRACT: Ion-coupled transport of neurotransmitter molecules by neurotransmitter:sodium symporters (NSS) play an important role in the regulation of neuronal signaling. One of the major events in the transport cycle is ion-substrate coupling and formation of the high-affinity occluded state with bound ions and substrate. Molecular mechanisms of ion-substrate coupling and the corresponding ion-substrate stoichiometry in NSS transporters has yet to be understood. The recent determination of a high-resolution structure for a bacterial homolog of Na(+)/Cl(-)-dependent neurotransmitter transporters, LeuT, offers a unique opportunity to analyze the functional roles of the multi-ion binding sites within the binding pocket. The binding pocket of LeuT contains two metal binding sites. The first ion in site

SUBMITTER: Caplan DA 

PROVIDER: S-EPMC2576368 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature