(A) Alignment of the catalytic domain structures from mammalian PARP-1 (PDB 1A26; green), PARP-2 (PDB 1GSO; yellow), and PARP-3 (PDB 3FHB; blue).
(B) Alignment of the catalytic domain structures from mammalian PARPs 1, 2, 3, 5a, 5b, 10, 12, 14, 15 (PDB 1A26, 1GSO, 3FHB, 2RF5, 3KR7, 3HKV, 2PQF, 3GOY, 3GEY, respectively). In (A) and (B), NAD+ has been modeled in based on a structure of diptheria toxin (PDB 1TOX).