Expression, purification, crystallization of fragments from the C-terminal region of DFF45/ICAD

DFF45/ICAD, which forms a heterodimer with DFF40/CAD as its DNase inhibitor and chaperone, plays a key role in nuclei DNA fragmentation in apoptosis. Several fragments from the C-terminal region of DFF45/ICAD have been cloned and expressed in Escherichia coli as His-tagged proteins. After purification to homogeneity, the recombinant proteins of three fragments were crystallized by the hanging-drop vapor-diffusion method. Of these, a crystal of DFF45c1 diffracted to 3.4 A in a capillary at 277 K and crystals of DFF45c2 diffracted to 3.2 A at cryotemperature using synchrotron radiation.