Studies on in vitro DNA synthesis: purification of dna C gene product containing dna D activity from Escherichia coli.

The conversion of varphiX174 single-stranded DNA to duplex DNA by extracts of E. coli requires products of the E. coli DNA replication genes. By use of this complementation system, the dna C gene product has been purified from wild-type E. coli as well as from a dna C temperature-sensitive mutant. The latter preparations are temperature sensitive when compared to the wild-type gene product. The dna C and dna D gene products copurify, have similar characteristics, are both temperature sensitive in preparations from dna C temperature-sensitive cells, and are both undetectable in preparations from dna D temperature-sensitive cells.