Proton-coupled amino-acid transporter that mediates the transmembrane transport of L-histidine and some di- and tripeptides from inside the lysosome to the cytosol, and plays a key role in innate immune response. Able to transport a variety of di- and tripeptides, including carnosine and some peptidoglycans (By similarity). Transporter activity is pH-dependent and maximized in the acidic lysosomal environment (By similarity). H(+)(out) + L-histidine(out) = H(+)(in) + L-histidine(in) a dipeptide(out) + H(+)(out) = a dipeptide(in) + H(+)(in) an L-amino acid tripeptide(out) + H(+)(out) = an L-amino acid tripeptide(in) + H(+)(in) H(+)(out) + N-acetylmuramyl-L-alanyl-D-isoglutamine(out) = H(+)(in) + N-acetylmuramyl-L-alanyl-D-isoglutamine(in) H(+)(out) + L-alanyl-gamma-D-glutamyl-meso-diaminoheptanedioate(out) = H(+)(in) + L-alanyl-gamma-D-glutamyl-meso-diaminoheptanedioate(in) glycyl-sarcosine(out) + H(+)(out) = glycyl-sarcosine(in) + H(+)(in) carnosine(out) + H(+)(out) = carnosine(in) + H(+)(in) Belongs to the major facilitator superfamily. Proton-dependent oligopeptide transporter (POT/PTR) (TC 2.A.17) family.