Characterization of arithmetic deoxyribonucleic acid synthesis at restrictive temperature in a dnaE mutant of Escherichia coli K-12.

The dna-293 mutation is shown to be a dnaE allele. The linear deoxyribonucleic acid synthesis previously observed in this mutant has been further characterized. The production of small deoxyribonucleic acid intermediates and their subsequent joining were identical in the mutant and its dnaE+ parent at 42.5 degrees C. Though the mutant cells continued to divide at the nonpermissive temperature, the rate of division was reduced. The data are consistent with a lack of production of replicationally active deoxyribonucleic acid polymerase III at the restrictive temperature.