Homing enzymes are site-specific DNases, encoded by introns or inteins. They specifically cleave intron - or intein - alleles of their genes and, thereby, facilitate homing of the introns or inteins that encode them.
Homing endonucleases recognize long, 14-40 base pairs sequences and are, therefore, extremely rare-cutting restriction enzymes. They allow the introduction of a single or several double-strand breaks into complex genomes. This capability makes the enzymes powerful tools in high-resolution physical mapping, genome organization analysis, gene cloning and site-directed induced-recombination and for studying double-strand-break repair in diverse biological systems