 The single @-@ strand annealing ( SSA ) pathway of homologous recombination repairs double @-@ strand breaks between two repeat sequences . The SSA pathway is unique in that it does not require a separate similar or identical molecule of DNA , like the DSBR or SDSA pathways of homologous recombination . Instead , the SSA pathway only requires a single DNA duplex , and uses the repeat sequences as the identical sequences that homologous recombination needs for repair . The pathway is relatively simple in concept : after two strands of the same DNA duplex are cut back around the site of the double @-@ strand break , the two resulting 3 ' overhangs then align and anneal to each other , restoring the DNA as a continuous duplex . 
