Fig. 1. XPA binds specifically to a dG-C8-AAF lesion.

a, b Representative AFM image of XPA bound to a non-damaged 538 bp DNA substrate (a, ND₅₃₈) or a 538 bp DNA with a single dG-C8-AAF lesion at 30% from one end (b, AAF₅₃₈). The dashed white line indicates the example in the cartoon below. Binding position was measured between the center of the protein to the closest DNA end as a percentage of total DNA contour length. c Percentage of XPA bound to DNA at ends (lavender) or internally (tan) on ND₅₃₈ (n = 163 particles) and AAF₅₃₈ (n = 277 particles). *p = 0.0118 by χ² test. d Histogram showing the distribution of internally bound XPA (n = 110 particles) position on ND₅₃₈. End-binders are shown in lavender. e Histogram and Gaussian fitting of internally bound XPA (n = 217 particles) positions on AAF₅₃₈. End binders are shown in lavender (not included in Gaussian fit). Gaussian is labeled with mean and s.d.