PEX19, also known as Peroxin 19, localizes to the outer surface of peroxisomes in liver cells. It is essential for peroxisome biogenesis in Saccharomyces cerevisiae. It is apparently involved in the initial stage of peroxisome membrane assembly, before the import of matrix protein. Recombinant human PEX19 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.