RECOMBINANT PLASMID

摘要

PURPOSE:A recombinant plasmid producing protein factor (EGF) having epidermal growth action efficiently, having a structural gene to code a specific polypeptide inserted into the recombinant plasmid. CONSTITUTION:A DNA base sequence of a structural gene of EGF and a translation control signal range is designed and synthesized to give an ECF gene (A) having a recognition breakage site of restriction enzyme XbaI between a gene codon at the top of the structural gene and SD sequence. Then manifestation plasmid vector pDR540 having tac promoter is scissored with BamHI to give cleft cloning vector (B). The components A and B are linked with ligase T4 to give recombinant plasmid pEGFSI (C). Then the component C is transduced to Escherichia coli JM103 and the prepared transformant is multiplied in a liquid medium. Then a recombinant plasmid pEGFSI (figure) into which a structural gene to code a modification type polypeptide having EGF in the downstream of the tac promoter is isolated from the multiplied mold.