DNA replication studies with coliphage 186: the involvement of the Escherichia coli DnaA protein in 186 replication is indirect

A genetic screen that can separate host mutants inhibiting coliphage 186 replication, but sensitive to P2 infection, helps isolate a rep mutant, which inhibits 186 and allows P2 replication. A 186 mutant capable of infecting the rep mutant is present in the phage replication initiation endonuclease gene A, indicating that Rep helicase and phage endonuclease interact directly during replication. DNA sequencing of the mutant reveals a glutamic acid-to-valine variation at the 155 position of the 694-residue gene A product.