Published online by Cambridge University Press: 14 April 2009
The survival of the plasmid RP 1–1 in E. coli depends on the presence of a functional polA gene. Unlike other plasmids that have this requirement, the replication of RP 1–1 is inhibited by chloramphenicol. RP 1–1 cannot be inherited by E. coli recA mutants, and inactivation of the recA gene product in a recAts mutant leads to destruction of the plasmid. RP 1–1 cannot be inherited by recB or recC E. coli unless the strains also carry a suppressor of these genes, such as sbcA or sbcB. The pattern of replication of RP 1–1 in E. coli K12 and its mutants suggests that the survival of this plasmid in this species is the outcome of a balance between DNA polymerase I-specified replication and exonuclease destruction.