{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"omics_type":["Unknown"],"volume":["288(21)"],"submitter":["Ma D"],"pubmed_abstract":["GadC, a central component of the Escherichia coli acid resistance system, is a Glu/GABA antiporter. A previous structural study and biochemical characterization showed that GadC exhibits a stringent pH dependence for substrate transport, with no detectable activity at pH values above 6.5. However, the substrate selectivity and the mechanism of pH-dependent transport activity of GadC remain enigmatic. In this study, we demonstrate that GadC selectively transports Glu with no net charge and GABA with a positive charge. A C-plug-truncated variant of GadC (residues 1-470) transported Gln (a mimic of Glu with no net charge), but not Glu, even at pH 8.0. The pH-dependent transport of Gln by this GadC variant was shifted ~1 unit toward a higher pH compared with Glu transport. Taken together, the results identify the substrate selectivity for GadC and show that the protonation states of substrates are crucial for transport."],"journal":["The Journal of biological chemistry"],"pagination":["15148-53"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC3663535"],"repository":["biostudies-literature"],"pubmed_title":["Substrate selectivity of the acid-activated glutamate/γ-aminobutyric acid (GABA) antiporter GadC from Escherichia coli."],"pmcid":["PMC3663535"],"pubmed_authors":["Ma D","Lu P","Shi Y"],"additional_accession":[]},"is_claimable":false,"name":"Substrate selectivity of the acid-activated glutamate/γ-aminobutyric acid (GABA) antiporter GadC from Escherichia coli.","description":"GadC, a central component of the Escherichia coli acid resistance system, is a Glu/GABA antiporter. A previous structural study and biochemical characterization showed that GadC exhibits a stringent pH dependence for substrate transport, with no detectable activity at pH values above 6.5. However, the substrate selectivity and the mechanism of pH-dependent transport activity of GadC remain enigmatic. In this study, we demonstrate that GadC selectively transports Glu with no net charge and GABA with a positive charge. A C-plug-truncated variant of GadC (residues 1-470) transported Gln (a mimic of Glu with no net charge), but not Glu, even at pH 8.0. The pH-dependent transport of Gln by this GadC variant was shifted ~1 unit toward a higher pH compared with Glu transport. Taken together, the results identify the substrate selectivity for GadC and show that the protonation states of substrates are crucial for transport.","dates":{"release":"2013-01-01T00:00:00Z","publication":"2013 May","modification":"2025-04-04T23:39:29.81Z","creation":"2019-03-27T01:10:22Z"},"accession":"S-EPMC3663535","cross_references":{"pubmed":["23589309"],"doi":["10.1074/jbc.M113.474502"]}}