 As DNA around the double @-@ strand break is cut back , the single @-@ stranded 3 ' overhangs being produced are coated with the RPA protein , which prevents the 3 ' overhangs from sticking to themselves . A protein called <unk> then binds each of the repeat sequences on either side of the break , and aligns them to enable the two complementary repeat sequences to anneal . After annealing is complete , leftover non @-@ homologous flaps of the 3 ' overhangs are cut away by a set of nucleases , known as <unk> / <unk> , which are brought to the flaps by the <unk> and <unk> proteins . New DNA synthesis fills in any gaps , and ligation restores the DNA duplex as two continuous strands . The DNA sequence between the repeats is always lost , as is one of the two repeats . The SSA pathway is considered mutagenic since it results in such deletions of genetic material . 
