HDDC2 (HD domain-containing protein 2), also known as hepatitis C virus NS5A-transactivated protein 2, is an enzyme that contains one HD domain and belongs to the HDDC2 family. It is predicted to exhibit phosphohydrolase activity. This protein is suggested to participate in nucleic acid metabolism, signal transduction and possibly other functions in bacteria, archaea and eukaryotes. The HD domain consists of highly conserved residues, specifically histidines or aspartates. Porphyria cutanea tarda, Parkinson’s disease and Stickler syndrome have all been associated with this protein.Recombinant human HDDC2 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.