FIGURE 3.

hCtf4 interacts with replicative Pols α, δ, and ϵ. A, Coomassie-stained SDS-10% polyacrylamide gel of purified DNA polymerases used in this study: lane 1, four-subunit Pol α-primase complex, 1.0 μg; lane 2, two-subunit Pol α, 0.6 μg; lane 3, two-subunit primase, 0.5 μg; lane 4, Pol δ, 0.8 μg; lane 5, DNA Pol ϵ, 1.5 μg. The subunits of each DNA polymerase are labeled. B, indicated levels of FLAG-tagged polymerases and untagged hCtf4 were incubated in reaction mixtures as described under “Experimental Procedures.” FLAG-antibody precipitated material was then resolved by SDS-10% PAGE followed by Western blot analyses using specific hCtf4 antibodies. “+” lanes denote reaction mixtures precipitated with FLAG antibodies in the presence of 1 mg/ml of FLAG peptide, whereas “−” lanes indicate precipitations carried out in the absence of FLAG peptide. C, quantification of results obtained in B.