TG and MAH conceived the study, participated in its design and coordination. TG, MAH, BS and FvZ participated in the computational analysis of peroxisomal proteins. TG, MAH, BS and HT drafted the manuscript. WH provided important insights in the study and the results. All authors read and approved the final manuscript.
We thank the referees for their many helpful suggestions ideas and corrections. We also thank Eugene Koonin for his comments on the manuscript. This work was supported by a grant from the Netherlands organization for scientific research (NWO). TG is recipient of an EMBO post-doctoral fellowship, ALTF 402-2005.