What is group II introns?

Group II introns can autosplice in vitro but are usually assisted by protein activities encoded in the intron. A single reading frame specifies a protein with reverse transcriptase activity, maturase activity, a DNA-binding motif, and a DNA endonuclease. The endonuclease cleaves target DNA to allow insertion of the intron at a new site. The reverse transcriptase generates a DNA copy of the inserted RNA intron sequence.