Figure 4
Effect of various purified PCNA fractions on the processivity of nucleotide incorporation by calf thymus pol δ. Incorporation of [α32P]dTMP by calf thymus pol δ was monitored by standard denaturing PAGE. The substrates used were (dA)~500-(dT)12–18 as template-primer and [α-32P]dTTP. Concentrations of PCNA, both wild-type and mutant proteins, are as indicated. h, human; dr, Drosophila melanogaster. NH2-terminally his-tagged-PCNA fractions are as indicated; wt, wild-type; Q123V, recombinant Drosophila PCNA containing a single amino acid, glutamine at position 123, changed to valine; dr119-133h, recombinant Drosophila PCNA containing the entire interdomain connector loop (amino acids 119-133) replaced with the corresponding human PCNA amino acids.