FIGURE 8.

Primase and DNA polymerase activities of the tetrameric polα-primase complex during the extension of the RNA primer on the polydT template. The poly-rA₁₅ primer annealed to polydT and extended by primase (lanes 2–4: 0.2 mm rATP), polα (lanes 5–7: 0.2 mm dATP), or the polα-prim complex (lanes 8–16) is shown. Lane 1, reaction without nucleotides; lanes 8–10, reactions containing 0.2 mm rATP; lanes 11–13, reactions containing 0.2 mm dATP; lanes 14–16, reactions containing 0.2 mm mixture of rATP and dATP. All reactions have an enzyme to primer/template ratio of 1:15 for balanced RNA and DNA pols activities. In each case, the time course of the reaction included points of 20, 60, and 240 s. nt, nucleotides.