Abstract
AIM2 (absent in melanoma 2) is an innate immune receptor for cytosolic double-stranded DNA (dsDNA). The engagement of dsDNA by AIM2 activates the AIM2 inflammasome, resulting in the cleavage of pro-interleukin-1β by caspase-1. The DNA-binding HIN-200 domain of mouse AIM2 bound to a 15 bp dsDNA and to an 18 bp dsDNA was purified and crystallized. The AIM2 HIN-200 domain in complex with the 15 bp DNA crystallized in the cubic space group I23 or I2(1)3, with unit-cell parameter a = 235.60 Å. The complex of the AIM2 HIN-200 domain and the 18 bp DNA crystallized in a similar unit cell. Diffraction data for the two complexes were collected to about 4.0 Å resolution. Mutagenesis and DNA-binding studies suggest that mouse AIM2 uses a similar surface to human AIM2 to recognize DNA.