Construction of plasmids carrying the cI gene of bacteriophage lambda.

Abstract

By techniques of recombination in vitro, a plasmid bearing the repressor gene (cI) of bacteriophage .lambda. fused to the promoter of the lac operon [Escherichia coli] was constructed. Strains carrying this plasmid overproduce .lambda. repressor. This functional cI gene was reconstituted by joining DNA fragments bearing different parts of that gene. Flush end fusion techniques, involving no sequence overlap, were necessary for the construction; in certain cases, the abutting of the DNA molecules bearing ends generated by different restriction endonucleases creates a sequence at the junction which is recognized by 1 of the restriction endonucleases.