ABSTRACT
The rare codons of a fragment in staphylococcal enterotoxin A gene were turned into the most high usage frequency codons in E. coli by overlap PCR technique. Genes of sea and seam were cloned into 7ZTS expression vector and transformed into JM109(DE3), respectively. The result shows that expression level of sea gene was very low, but the expression level of seam was as high as 15% of total cell proteins. The expression product shows activity of antitumor in vivo.
Subject(s)
Animals , Male , Mice , Base Sequence , Codon , Genetics , Electrophoresis, Polyacrylamide Gel , Enterotoxins , Genetics , Metabolism , Pharmacology , Escherichia coli , Genetics , Gene Expression Regulation, Bacterial , Molecular Sequence Data , Neoplasms, Experimental , Drug Therapy , Pathology , Point Mutation , Recombinant Proteins , Genetics , Metabolism , PharmacologyABSTRACT
An about 700 bp DNA fragment was amplified from genome DNA of S. aureus TSTw by PCR. This fragment was cloned into pGEM-7Zf(+) and the recombinant plasmid was transformed into E. coli DH5 alpha. The sequencing result of the recombinant plasmid demonstrated that it contains seb gene with 717 bp (without signal encoding region of 81 bp) which has the same nucleotide sequence as described in literature. The seb gene was cloned into expression vector 7ZTS and was transformed into E. coli JM109 (DE3). The expression level of SEB was as high as 33.3% of the cell total proteins.