[recA gene dependence of chromosome replication of Escherichia coli initiated by mini-F plasmids integrated at predetermined sites].

mini-F plasmids carrying particular chromosomal fragments were constructed. Through homologous recombination they were expected to integrate onto predetermined sites of the chromosome of dnaA46 strain LC381. Chromosome replication of suppressive integration (Sin) strains were recA dependent or independent according to the site of integration of the plasmid: chromosome replication of those with the plasmid integrated close to oriC were found to be recA dependent at 40 degrees C; those with the plasmid integrated between oriC and terC were recA dependent on rich medium but independent on minimal medium; those with the plasmid integrated close to terC were recA dependent even on minimal medium.