SurA is a periplasmic peptidyl-prolyl isomerase (PPIase) and chaperone of Escherichia coli and other Gram-negative bacteria. This protein is a major factor in the biogenesis of beta-barrel outer membrane proteins (OMPs) and plays an integral role in cell envelope homeostasis and cell envelope functions. It is essential for the survival of E.coli in stationary phase and required for pilus biogenesis. Recombinant E.coli SurA protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography.