SSU72 RNA polymerase II CTD phosphatase homolog, also known as SSU72, is a highly conserved homologue of yeast Ssu72, a CTD phosphatase and a component of the polyadenylation/ termination machinery. Existing as multiple alternatively spliced isoforms, SSU72 interacts with TFIIB, Rb and DNAM-1 and functions to catalyze the dephosphorylation of target proteins, possibly playing a role in RNA processing and termination via dephosphorylation of Pol II. Recombinant human SSU72 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.