Preferential binding of IFI16 protein to cruciform structure and superhelical DNA

► IFI16 can form protein-DNA complexes with supercoiled DNA. ► IFI16 protein binds strongly to negatively superhelical plasmid DNA at a native superhelical density. ► IFI16 strongly prefers binding to cruciform DNA over linear duplex DNA. ► Electrophoretic retardation assay is suitable for determining IFI16-DNA complexes.