On the Process of Cellular Division in Escherichia coli, V. Incorporation of Deoxynucleoside Triphosphates by DNA Thermosensitive Mutants of Escherichia coli Also Lacking DNA Polymerase Activity

Double mutants of Escherichia coli were constructed by combining DNA thermosensitive mutations affecting either DNA initiation (DnaA) or elongation (DnaB) with the Pol A1 mutation, which abolishes DNA polymerase activity. Incorporation of labeled deoxynucleoside triphosphates was studied in these mutants using toluene-treated cells. This incorporation was found to be exactly correlated with the capacity of the mutants to synthesize DNA in vivo.