Intracisternal A particle-promoted polypeptide(IPP) is a 66kDa protein(584 amino acids), which contains an N-terminal POZ protein-protein interaction domain and a C-terminla kelch repeat domain consisting of six tandem arranged repeats. The POZ domain(also called BTB domain) is present near the N-terminus of a fraction of zinc finger proteins and in protein that contain the pfam01344 motif such as kelch and pox virus proteins. The BTB/POZ domain mediates homomeric dimerization and in some instances heteromeric dimerization. POZ domains from several zinc finger proteins have been shown to mediate transcriptional repression and to interact with components of histone deacetylase co-repressor complexes including N-coR and SMRT. IPP-POZ domain(1- 157aa) was overexpressed in E.coli and purified by using conventional chromatography techniques.