Transporter for gamma-aminobutyrate (GABA) (PubMed:8297211, PubMed:8557687). Transport is driven by the membrane potential (PubMed:8297211). Can also transport a number of GABA analogs such as nipecotic acid or muscimol (PubMed:8557687). 4-aminobutanoate(in) + H(+)(in) = 4-aminobutanoate(out) + H(+)(out) Uptake is stimulated by ammonium sulfate and abolished by 2,4-dinitrophenol (PubMed:8297211). Is affected both topologically and kinetically by phospholipid composition of the membrane (PubMed:15890647). In cells lacking phosphatidylethanolamine (PE), the N-terminal hairpin is inverted relative to the membrane and the rate of GABA transport is reduced by more than 99% (PubMed:15890647). Amino-acid degradation; 4-aminobutanoate degradation. Monomer. Induced by RpoS, but not in response to multiple stress conditions. Belongs to the amino acid-polyamine-organocation (APC) superfamily. Amino acid transporter (AAT) (TC 2.A.3.1) family.