GroES protein is the co-chaperonin of GroES in E.coli and assists protein folding. GroEL mediated folding requires the co-chaperonin GroES which is essential for viability. GroES is composed of a single heptameric ring of 10kDa subunits that binds to the ends of the GroEL cylinder. GroES gene was amplified by PCR from E.coli and cloned into an expression vector. This protein was overexpressed in E.coli and was purified by using conventional chromatography techniques.