Fig. 2: Mechanism of DNA base damage recognition by AAG in the nucleosome.

a–c AAG identifies the damaged base by inserting the β3–β4 hairpin into the damage-located minor groove, and displaces the damaged base using Y162. d, e Overview of interactions between the flipped post-catalytic AP site and AAG residues (Y127, H136, Y159, R182, H266). f–h Close-up views of the detailed interactions between the post-catalytic AP site and AAG. i Structural comparison of AAG–NCP–30AP, E125Q AAG/εA-DNA complex (PDB: 1EWN) and AAG complexed to DNA containing a pyrrolidine abasic nucleotide (PDB: 1BNK). Zoom-in view shows the local conformational variations among three structures.