SGTA, also known as SGT or hSGT, is a ubiquitously expressed protein that contains three TPR protein-protein interaction repeats. This protien is believed to function as a component of the androgen receptor (AR)-chaperone-cochaperone complex, acting as a cochaperone involved in androgen signaling. In addition, SGTA functions as a cochaperone that binds directly to HSC70 and HSP70 and regulates their ATPase activity. On the basis of its role in apoptosis and androgen signaling, SGTA is a potential candidate for PCOS (polycystic ovary syndrome), a disorder characterized by androgen excess, obesity and menstrual disturbances. Recombinant SGTA protein, fused to His-tag at C-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.