KINETIC-ANALYSIS OF PLASMID RECOMBINATION IN ESCHERICHIA-COLI-CELLS

A method was developed for kinetic analysis of plasmid recombination. Hybrid plasmids were constructed that contain Vibrio fischeri luxA and luxB genes coding for luciferase. Recombination of these plasmids yie lded active copies of the luxA gene, thus causing cell luminescence. T o study the intramolecular recombination, a pF8 plasmid was constructe d that contains two copies of the luxA gene with point mutations at th e XhoI and HinIII sites. Kinetic analysis of both replication and reco mbination of these plasmids was carried out. A parameter was introduce d characterizing the probability of recombination per one division cyc le. It was suggested that this parameter (P) should be used as the maj or characteristic of recombination. The P values for several E. coil K 12 strains were determined.