Inhibition of protein synthesis transiently stimulates initiation of minichromosome replication in Escherichia coli.

Replication of oriC-dependent minichromosomes was found to be transiently stimulated when protein synthesis was inhibited by the addition of chloramphenicol. Initiation of replication was also induced by amino acid starvation of relA mutant strains and a nutritional upshift. The results are explained on the basis that these treatments rendered RNA polymerase more available for participation in the initiation process. As a consequence, the oriC duplex may be transcriptionally activated to an open form, a necessary prerequisite for DNA polymerization.