Fig. 4.

In vivo and In vitro GGI excision. (A) Schemes of the in vitro (Left) and in vivo (Right) assays used. The color code is as in Fig. 1. (B) In vitro recombination reactions using plasmids containing the dif_Ng-dif_Ng cassette. After DNA restriction, substrate (*) and products (HJ, P1, and P2) are separated by electrophoresis. In vivo recombination reactions using E. coli strains containing the dif_Ng-dif_Ng cassette inserted at the dif locus. Recombination was scored as the appearance of kanamycin-sensitive colonies after production of either XerD_Ng or XerDγ_Ng. The experiment was done in wt and ΔC ftsK strains (Methods). –, Less than 2%; ±, 2–10%; +, 10–50%; ++, 50–100% kanamycin colonies (see also Table S1). (C) Same as B but for dif_Ng-dif_GGI cassettes.