Abstract: Staphylococcus aureus causes a wide spectrum of human and animal diseases,including skin and soft-tissue infections and infectious endocarditis. IsdD gene is one of the important members of iron-regulated surface determinant (Isd) system from S.aureus. According to the sequence of IsdD gene published in GenBank,a pair of specific primers was designed and synthesized.Using the total genome DNA from S.aureus Wood46 strain as template,IsdD coding sequences were amplified by PCR method. The PCR product which had been digested by NcoⅠ and XhoⅠ restriction endonucleases was inserted into pET32a(+) vector subsequently. The recombinant plasmids,designated as pET32a(+)-IsdD,were transformed into E.coli BL21. The sequence analysis results showed the homologies of both nucleoside sequence of target gene and its deduced amino acid sequence to compare with standard sequence of IsdD could reach above 98%. SDS-PAGE analysis results indicated the recombinant IsdD protein of 61.3 ku was successfully expressed by E.coli BL21 induced with IPTG. The results obtained in this report provide important basis for further study on structure and function of the IsdD protein.

Key words: Staphylococcus aureus; IsdD gene cloning; IsdD protein expression