Bacterio phage lambda escherichia coli k 12 vector host system for gene cloning and expression under lactose promoter control part 1 dna fragment insertion at the lacz eco r i restriction site
Pourcel, C.; Marchal, C.; Louise, A.; Fritsch, A.; Tiollais, P.
Molecular and General Genetics 170(2): 161-170
Bacteriophage lambda vectors, derived from .lambda.plac5, were constructed. Their genomes have only 1 EcoRI restriction site, located near the end of the .beta.-galactosidase gene. Recombinants, constructed in vitro, having a DNA fragment inserted in the EcoRI site, are lac- and can be easily recognized. Expression of such foreign genes is then under the control of the lac promoter. Mutations Qam73 and Sam7 greatly increase the amount of .beta.-galactosidase synthesized by the vector bacteriophage. The .lambda.ZEQS vector was certified B2 (EK[biological containment level]2) by the French control commission Recombinaisons genetiques in vitro. [Escherichia coli K12 derivatives were used.].