Investigation of the allosteric coupling mechanism in a glutamate transporter homolog via unnatural amino acid mutagenesis.

ABSTRACT: Glutamate transporters harness the ionic gradients across cell membranes for the concentrative uptake of glutamate. The sodium-coupled Asp symporter, Glt_Ph is an archaeal homolog of glutamate transporters and has been extensively used to understand the transport mechanism. A critical aspect of the transport cycle in Glt_Ph is the coupled binding of sodium and aspartate. Previous studies have suggested a major role for hairpin-2 (HP2), which functions as the extracellular gate for the aspartate binding site, in the coupled binding of sodium and aspartate to Glt_Ph In this study, we develop a fluorescence assay for monitoring HP2 movement by incorporating tryptophan and the unnatural amino acid, p-cyanophenylalanine into Glt_Ph We use the HP2 a

SUBMITTER: Riederer EA 

PROVIDER: S-EPMC6690018 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature