Sequence-specific oligodeoxyribonucleotide cleavage by a major-groove-positioned metal-binding ligand tethered to C-5 of deoxyuridine

Highly efficient cleavage of the single-stranded oligonucleotide 5′-d(CTGGCTCACAAATACCAC TGAGATCTTTTTC)-3′ (O1) at nucleotides G20, A21, and G22 was achieved by an iron-bipyridine complex linked to a targeting oligonucleotide 5′-d(AAA AAG ATC T*CA)-3′ (O2) through -SCH2CH2NHC(O)- at C5 of a 2′-deoxyuridine (T*).