The I-CreI entry in FlyBase represents the homing endonuclease encoded by the self-splicing group-I intron of the 23S rRNA gene of the Chlamydomonas reinhardtii chloroplast genome. I-CreI recognizes a 19-24bp target site (RS(I-CreI)), with cleavage generating a double-strand DNA break (PMID:1398106, PMID:8437585).