Chromosomal location of att P7, the recA-independent p7 integration site used in the suppression of Escherichia coli dnaA mutations.

Conjugational and transductional analyses were used to determine the chromosomal location of attP7, the recA-independent integration site used by bacteriophage P7 to suppress host dnaA mutations. The site of integration was found to be between tolC and dnaG. An increase in transduction frequencies was observed for markers surrounding attP7 when P7 was integrated. Under these conditions, all pairs of markers in this region, including those separated by attP7, were cotransduced at frequencies higher than normal, indicating the possible production of P7 specialized transducing particles.