Fig. 4.

Endonucleolytic activity of the large terminase subunit p03 and the stimulatory effect of the small subunit p01 on this activity. (A) Endonucleolytic activity of p03 in the absence of p01, using the cos-containing plasmid pMD-cos as the substrate. The concentrations of p03 are indicated (μM). The 1-kb DNA ladder marker is shown to the right (M). L, linearized plasmid DNA; CCC, covalently closed circular plasmid DNA. (B) Influence of different ratios of the small and large subunit (p01:p03) on endonucleolytic activity. The concentration of p03 was held constant at 0.8 μM