GO:0015495

Catalysis of the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: gamma-aminobutyric acid(out) + H+(out) = gamma-aminobutyric acid(in) + H+(in). [TC:2.A.18.5.1, TC:2.A.3.1.4, TC:2.A.3.4.2]