Involved in peroxisome biosynthesis and integrity. Assembles membrane vesicles before the matrix proteins are translocated. As a docking factor for PEX19, is necessary for the import of peroxisomal membrane proteins in the peroxisomes. Interacts with PEX19. Identified in all tissues analyzed, with the strongest expression in liver and in testis. Belongs to the peroxin-3 family.