LAMBDA-PHAGE BETA-PROTEIN AND EXONUCLEASE-PRODUCING ESCHERICHIA COLI

摘要

PURPOSE:To easily produce the titled substance at a large quantity, by inserting a beta-protein of lambda-phage and structural gene of exonuclease into a plasmid having sensitive repressor and promoter of lambda-phage and introducing the plasmid into Escherichia coli. CONSTITUTION:EcoRV-B fragment produced by treating lambda-phage with restriction enzyme EcoRV is linked to pBR322 with a DNA ligase to obtain pBL1 of 9.7kb. Said pBR322 can be produced by cutting the lambda-phage similarly with EcoRV. The plasmid is treated with restriction enzymes EcoRV and XmnI, a DNA fragment of 2.5kb containing beta-protein of lambda-phage and exonuclease structural gene is separated and an adhesive end is formed with BamHI linker and BamHI. pMY12-6 containing lambda-phage promoter and temperature-sensitive repressor CI854 gene is treated with BamHI to effect ring-opening reaction and the product is linked with said fragment by DNA ligase treatment. A recombinant plasmid pML1-1 can be produced by this process to enable induction manifestation.