Nucleobase-proton symporter that mediates the sodium-dependent binding and uptake of 5-aryl-substituted hydantoin compounds (PubMed:16621827, PubMed:24952894). 5-indolyl methyl hydantoin and 5-benzyl hydantoin are the preferred substrates, with selectivity for a hydrophobic substituent in position 5 of hydantoin and for the L isomer over the D isomer (PubMed:16621827, PubMed:24952894). Inhibited by dinitrophenol, 5-(2-naphthylmethyl)-D-hydantoin (D-NMH), 5-(2-naphthylmethyl)-L-hydantoin (L-NMH), 5-bromovinylhydantoin (BVH) and 5-indolylmethyl-L-hydantoin (L-IMH) (PubMed:16621827, PubMed:24952894). The affinity of benzyl-hydantoin is increased over 10-fold in the presence of 15 mM of sodium (PubMed:18927357). Optimum pH is 6.6. Belongs to the purine-cytosine permease (2.A.39) family.