A) Sequence-selective cleavage of [5′-32P]-end labeled 64-nt hairpin DNA 7 by BLM A5. Lane 1, radiolabeled 7 alone; lane 2, 5 μM Fe2+; lane 3, 5 μM BLM A5; lane 4, 1 μM Fe(II)•BLM A5; lane 5, 2.5 μM Fe(II)•BLM A5; lane 6, 5 μM Fe(II)•BLM A5; lane 7, G+A lane. B) Sequence-selective cleavage of [3′-32P]-end labeled 64-nt hairpin DNA 7 by BLM A5. Lane 1, radiolabeled 7 alone; lane 2, 10 μM Fe2+; lane 3, 5 μM BLM A5; lane 4, 1 μM Fe(II)•BLM A5; lane 5, 2.5 μM Fe(II)•BLM A5; lane 6, 5 μM Fe(II)•BLM A5; lane 7, Maxam-Gilbert G+A lane.