Introns encode LAGLIDADG (IPR004860), a homing endonuclease (HEnase) that provides mobility to its host genetic elements. Two tandemly repeated homing endonuclease-like domains compose LAGLIDADG HEnases. The homing endonuclease is a prime example. LAGLIDADG domain Group I intron-encoded endonucleases are a component of the PD-(D/E)XK(PF11645) endonuclease family. This family is a member of the PD-(D/E)XK superfamily.