Figure 3.

hpol η incorporates rNTPs opposite CPD lesion within human cell extracts. A, hpol η–deficient (XP-V, XP30RO) and corrected cell (XP30RO + Pol η) extracts were prepared, and each cell extract (1 mg protein/ml) was tested with 1 μm native or CPD-containing primer/template DNA substrates. B, the corrected cell extracts with DNA/DNA(dT). C, the XP-V cell extracts with DNA/DNA(dT). D, the corrected cell extracts with DNA/DNA(CPD). E, the XP-V cell extracts with DNA/DNA(CPD). To decrease degradation, a ssDNA, poly dA (100 μm) was added in each reaction. The reactions were conducted in the presence of H₂O (negative control), dNTPs, or rNTPs (1 mm each nucleotide) for 10, 30, and 60 min. P indicates the primer and the bands below the primer are degradation products. See “Oligonucleotide substrates” under “Experimental procedures” for the oligonucleotide sequences used.