Proton-coupled amino-acid transporter that transports free histidine and certain di- and tripeptides, and is involved in innate immune response (By similarity). Also able to transport carnosine (PubMed:31073693, PubMed:31254495). Involved in the detection of microbial pathogens by toll-like receptors (TLRs) and NOD-like receptors (NLRs), probably by mediating transport of bacterial peptidoglycans across the endolysosomal membrane: catalyzes the transport of certain bacterial peptidoglycans, such as muramyl dipeptide (MDP), the NOD2 ligand (By similarity).
