Suppression of dnaC alleles by the dnaB analog (ban protein) of bacteriophage P1.

The dnaB analog protein produced by the ban gene of bacteriophage P1 was shown to suppress several Escherichia coli dnaC alleles. Suppression of dnaC7 temperature sensitivity in P1 lysogens of a dnaC7 mutant was complete at all temperatures. For the dnaC2 and dnaC28 alleles, suppression was observed only at intermediate temperatures. Though these intermediate temperatures were sufficient to completely restrict the mutants, at higher temperatures the suppression was not observed. No suppression of the dnaC1 allele was detected. These results have implications concerning the requirement for the dnaB-dnaC complex at the various stages of deoxyribonucleic acid replication.