DNA topoisomerase 6 (TOP6) belongs to a novel family of type II DNA topoisomerases present, other than in archaebacteria, only in plants. Here we report the isolation of full-length cDNAs encoding putative TOP6 sub-units A and B from rice (Oryza ), preserving all the struc-tural domains conserved among archaebacterial TOP6 homologs and eukaryotic meiotic recombination factor SPO11.