ARL9 (ADP-ribosylation factor-like protein 9) belongs to two novel subfamilies coding for small GTPases that we found to be highly conserved among eukaryotes. Recombinant human ARL9 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by conventional chromatography, after refolding of the isolated inclusion bodies in a renaturation buffer.