Deletion of 60 kilobase pairs of DNA from the terC region of the chromosome of Escherichia coli.

The terminus of replication (terC) of the chromosome of Escherichia coli is located between the rac (min 30.0) and manA (min 35.7) loci, presumably close to the trg (min 31.4) locus. We have used a strain containing lambda reverse (min 30.0) and trg-2::Tn10 (min 31.4) to obtain deletions of the entire 60 kilobase pair region that separates these elements. Strains harboring these deletions possessed fusion fragments that contained DNA homologous to both lambda reverse and trg region DNA. In addition, chromosomal DNA normally present between min 30.0 and min 31.4 was absent in these strains. The strains had no readily apparent mutant phenotype, which demonstrates that this large region of DNA is not essential for normal growth.