passages.id: split_4_test_2720_passage
passages.type: progene_text
passages.text: The specific activities of NaeI - 43K and NaeI - 43R and their relative sensitivities to salt , the topoisomerase - inhibiting drug N - [ 4 - ( 9 - acridinylamino ) - 3 - methoxyphenyl ] methane - sulfonamide ( amsacrine ) and single - stranded DNA showed that the two activities are similar .