Distinct roles of the Na⁺ binding sites in the allosteric coupling mechanism of the glutamate transporter homolog, Glt_Ph.

ABSTRACT: Glutamate transporters carry out the concentrative uptake of glutamate by harnessing the ionic gradients present across cellular membranes. A central step in the transport mechanism is the coupled binding of Na+ and substrate. The sodium coupled Asp transporter, GltPh is an archaeal homolog of glutamate transporters that has been extensively used to probe the transport mechanism. Previous studies have shown that hairpin-2 (HP2) functions as the extracellular gate for the aspartate binding site and plays a key role in the coupled binding of sodium and aspartate to GltPh. The binding sites for three Na+ ions (Na1-3) have been identified in GltPh, but the specific roles of the individual Na+ sites in the binding process have not been elucidated. In this study, we developed assays to probe Na+

SUBMITTER: Riederer EA 

PROVIDER: S-EPMC9171649 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature