Fig. 2
From: Molecular snapshots of APE1 proofreading mismatches and removing DNA damage
The APE1 exo substrate complex. a, b Active site of APE1 a exo and b endo (PDB 5DFI) substrate complexes with key residues indicated. The C1ʹ of the 3ʹ mismatched base and THF are indicated by red arrows. The cleavage sites are indicated by black arrows. 2Fo–Fc map density (1σ) for the 3′ mismatched and flanking base is shown in light blue. c, d Surface representation of c exo and d endo active sites showing the varying bends of the DNA and displacement of the exo 5ʹ-P to vacate the active site for the 3ʹ mismatched base. The 5′-P is shown as surface in red. The protein side chains are shown in yellow (exo) or green (endo) and DNA residues in gray
