Interaction of bleomycin with DNA

It has been shown previously that two structural domains of bleomycin mediate the interaction of the antitumor antibiotic with DNA. At least three lines of evidence indicate that the metal binding domain is the predominant partner, and is responsible for the sequence selectivity of DNA cleavage observed for Fe(II)•BLM. The bithiazole + C-terminus has been shown previously to bind to DNA, but not to exhibit any sequence selectivity. Presently, it is shown that the bithiazole + C-terminus may also exhibit sequence selectivity, albeit not in the same fashion as bleomycin itself. The potential of this selectivity to contribute to the recognition of high affinity sites on DNA by bleomycin is discussed.