Mediates the proton-dependent uptake of dipeptides. Shows higher affinity for dipeptides with a negatively charged amino acid residue at the N-terminal position, such as Asp-Ala and Glu-Ala. Also displays specificity for Ala-Ala, Ala-Tyr and Tyr-Ala. Transport is inhibited by the proton ionophore carbonyl cyanide m-chlorophenylhydrazone (CCCP). Belongs to the major facilitator superfamily. Proton-dependent oligopeptide transporter (POT/PTR) (TC 2.A.17) family.