| abstract |
Abstract: A novel Escherichia coli plasmid is described. The plasmid has, between the Shine-Dalgarno sequence and the transla-tion start codon, a base sequence different from the corresponding, originally occurring region in the .beta.-galactosidase operon and contains, upstream therefrom, the region of a hybrid promoter between the Escherichia coli trp promoter and the lac promoter and, at an entirely independent site, a lac promoter repressor gene. Employing an Escherichia coli transformant carrying the plasmid, a useful polypeptide such as h-IFN-.gamma. can be produced in high yield. |