OVERPRODUCTION OF THE TOXIC PROTEIN, BOVINE PANCREATIC DNASEI, IN ESCHERICHIA-COLI USING A TIGHTLY CONTROLLED T7-PROMOTER-BASED VECTOR

A synthetic gene coding for bovine pancreatic DNaseI has been cloned u nder the control of a T7 promoter present on the plasmid pET11. This c onstruct yields a stable Escherichia coli transformant only when trans cription from this promoter is tightly controlled. Production of recom binant DNaseI (reDNaseI) is achieved by infection of the cells with a mutant lambda phage, CE6, which carries the gene encoding T7 RNA polym erase. Induced bacterial cultures yield in excess of 2 mg per litre of reDNaseI after purification.