Fig. 4. Ability of pol η to elongate DNA chains past lesions. Sets of 5′-³²P-labeled 17mer (A, B, E, F, G, J and K) or 18mer (C, D, H, I, L and M) primers, which contained different sequences at their 3′ ends (indicated by N, where N was A, C, G and T in lanes 1–4, 5–8, 9–12 and 13–16, respectively), were annealed to 30mer templates. Increasing amounts of pol η or pol α were incubated with these primed templates. The auto-radiograms of the gels are shown. The amounts of pol η were 0.12 fmol in lanes 2, 6, 10 and 14, 0.7 fmol in lanes 3, 7, 11 and 15 (A–D, F, H, J and L), 0.25 fmol in lanes 2, 6, 10 and 14, and 1.4 fmol in lanes 3, 7, 11 and 15 (E, G, I, K and M). Pol α (lanes 4, 8, 12 and 16) was present at 4.7 fmol. (A) Undamaged control for the CPD template with a 17mer primer. (B) CPD at the bridged TT with a 17mer primer. (C) Undamaged control for the CPD template with an 18mer primer. (D) CPD at the bridged TT with an 18mer primer. (E) The AP analog at X with a 17mer primer. (F) Undamaged control for the AAF-G template with a 17mer primer. (G) AAF-G at the indicated site with a 17mer primer. (H) Undamaged control for the AAF-G template with an 18mer primer. (I) AAF-G at the indicated site with an 18mer primer. (J) Undamaged control for the cisplatin-GG template with a 17mer primer. (K) Cisplatin-GG at the indicated site with a 17mer primer. (L) Undamaged control for the cisplatin-GG template with an 18mer primer. (M) Cisplatin-GG at the indicated site with an 18mer primer.