Research on DnaA in the early days

The Escherichia coli chromosome is a circular double helix. DNA polymerase, therefore, cannot use it directly as a template for polymerization until it has first been unwound. The DnaA protein opens the chromosome at a unique and specific site (oriC), which allows the polymerase to begin DNA replication. François Jacob and Sydney Brenner predicted the existence of the initiator protein, DnaA, back in the early 1960s. In order to demonstrate the existence of the hypothetical initiator, identification and isolation of dnaA mutants were undertaken. In the following, I recount, in a historical setting, the original research done on the identification and isolation of dnaA mutants.