Abstract: A novel dual specificity protein phosphatases named sPP2C (protein phosphatase 2C, Staphylococcus aureus) was cloned from Staphylococcus aureus gene library. sPP2C gene contained 741bp. The protein contained 247 amino acids and a protein phosphatases 2C catalytic domain. The molecular weight was 26.1 kDa, and pI was 4.95. sPP2C was expressed in Ecoli.Rossetta and purified by affinity chromatography. Enzyme property research revealed that sPP2C showed no phosphatase activity towards pNPP（p-nitrophenyl phosphate）which is a common synetic protein phosphatase substrate, whereas sPP2C showed phosphatase activity towards oligopetptides containing pSer/Thr and pTyr, indicating that sPP2C is a novel protein phosphatase with dual substrate specificity.

Key words: pNPP, dual specificity phosphatase, phosphatase activity , sPP2C, pNPP, dual specificity phosphatase, phosphatase activity