Binds to the C-terminal PTS1-type tripeptide peroxisomal targeting signal (SKL-type) and plays an essential role in peroxisomal protein import. Its distribution appears to be dynamic. It is probably a cycling receptor found mainly in the cytoplasm and as well associated to the peroxisomal membrane through a docking factor (PEX13). Ubiquitination at Cys-6 is UBC4-independent but requires the presence of PEX4. Ubiquitination at Lys-18 and Lys-24 are UBC4-dependent. Present with 2070 molecules/cell in log phase SD medium. Belongs to the peroxisomal targeting signal receptor family.