FIG. 9.

Comparison of zebrafish APE and human APE1. Although the zebrafish APE (PDB identifier, 203C, light gray) also includes an extended N-terminus similar to that found in the human APE1 (PDB identifier, 203H, dark gray), it does not have redox activity. As shown in these ribbon renderings, the zebrafish and human enzymes are structurally very similar, including the N-terminal residues. Conserved Cys residues, including 93, 99, 208, 296, and 310, are shown in black stick renderings for the human enzyme.