ABSTRACT
To construct expressing vector carrying esat6 gene and express this protein in Streptococcus gor-donii GP251. esat6 gene was amplified by PCR with specific primer from genome of Mycobacterium tuber-culosis (MTB)H37Rv. Inserted esat6 into the pMD18-T vector by T/A clone to get recombinant vector pMD18-esat6. Then digested pMD18-esat6 with restriction enzyme, esat6 was cloned to vector PSMB104 and expressed in Streptococcus gordonii GP251. The expression of esat6 protein was detected by Tricine-SDS-PAGE and Western-blot, ELISA technique was also used to detect its secretory volume. Re-striction endonuclease, PCR, Tric ine-SDS-PAGE and Western-blot confirmed that esat6 gene was cloned into expressing vector successfully, and a 10 kD protein secreted in Streptococcus gordonii GP251, this pro-tein has a good immunogenicity. The expression vector of esat6 gene was constructed, and esat6 protein ex-pressed in Streptococcus gordonii1 successfully, it will be benefit for future study.