SUGT1, also known as suppressor of G2 allele of SKP1, is a homolog of the yeast protein SGT1, a regulator of the cell cycle that is essential for G1/S and G2/M transitions. It contains a CS domain, a SGS domain, a p23 domain and three tetratricopeptide repeats (TPR). This protein associates with Skp1 p19 and CUL-1, subunits of the SCF ubiquitin ligase complex, and is thought to play a role in protein degradation. In addition, it is required for the kinetochores assembly, and has function as a co-chaperone for HSP90. Recombinant human SUGT1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.