Single amino acid substitution enhances bacterial expression of PARP-4D214A.

Poly(ADP-ribose) polymerase-1 (PARP-1) is the canonical member of the PARP family of enzymes and modulates many crucial nuclear functions. PARP-1 is involved in apoptosis and is the substrate of caspase-3, a protease that cleaves PARP-1 at the conserved sequence 211DEVD214. To generate a caspase-3-uncleavable PARP-1, we introduced an amino acid substitution D214-->A214 at the site of cleavage.