Figure 6.

NEIL1 can act downstream of TDG: 50 nM TDG and 100 nM of active NEIL1 or the catalytically impaired NEIL1 P2T variant were incubated (37 °C, 60 min) with 20 nM dsDNA. The ³²P-radiolabelled strand of the DNA contained at position 20 a 5fC (left) or 5caC (right). Reaction products were not subjected to alkaline conditions and were analysed by denaturing gel electrophoresis and autoradiography. NEIL1 and TDG together catalysed a much greater number of strand breaks than NEIL1 alone. The data show that NEIL1 can efficiently act downstream of TDG to process abasic sites, despite the tendency of TDG to stick to AP-sites⁴¹.