Figure 3.

T7 gene 4 primase-dependent DNA synthesis. (A) The extension of RNA primers synthesized by T7 63-kDa gene 4 protein in the presence of ATP and CTP by wild-type T7 DNA polymerase (○) or T7 polΔ401–404 (●) was determined as described in Materials and Methods. The amount of incorporation of [³H]dTMP is plotted against different polymerase concentrations. (B) The ability of the wild-type T7 DNA polymerase (○) or T7 polΔ401–404 (●) to extend synthetic tetraribonucleotide primers in a reaction containing T7 63-kDa gene 4 protein was determined as described in Materials and Methods. The amount of incorporation of [³H ]dTMP was plotted against different concentrations of the tetraribonucleotide 5′-pACCA-3′.