Invasion of protein coding genes by green algal ribosomal group I introns

► Group I introns at two positions within the chloroplast rbcL gene in Chlorophyceae. ► rbcL group I introns derived from ribosomal RNA group I introns. ► rbcL462 introns of group IA2 encoding GIY-YIG homing endonuclease. ► rbcL699 introns of group IA1, some encoding HNH homing endonucleases.