FIGURE 4.

Pol δ^* shows inefficient capacity for idling. The inset shows the sequence context of the DNA substrate from Fig. 3A. Idling assays were carried out at a constant DNA concentration of 7 nm and increasing DNA polymerase concentrations, as described under “Experimental Procedures.” PRI, the 5′-³²P-labeled 30-mer primer; BLO, the 5′-phosphorylated 27-mer blocking oligonucleotide.