Metal cofactors (Mg and Mn) modulate both specific DNA binding and strand cleavage in the TaqI endonuclease (Cao, W., Mayer, A. N., and Barany, F. (1995) Biochemistry 34, 2276–2283). This work attempts to establish the structural basis of TaqI-DNA-metal interactions using an affinity cleavage technique. The protein was cleaved by localized hydroxyl radicals generated by oxidizing Fe within the ...

Metal cofactors (Mg2+ and Mn2+) modulate both specific DNA binding and strand cleavage in the TaqI endonuclease (Cao, W., Mayer, A. N., and Barany, F. (1995) Biochemistry 34, 2276-2283). This work attempts to establish the structural basis of TaqI-DNA-metal2+ interactions using an affinity cleavage technique. The protein was cleaved by localized hydroxyl radicals generated by oxidizing Fe2+ wit...

We report a direct technique for determining the binding sites of small molecules on naturally occurring heterogeneous DNA. Methidiumpropyl-EDTA.Fe(II) [MPE.Fe(II) cleaves double helical DNA with low sequence specificity. Using a combination of MPE.Fe(II) cleavage of drug-protected DNA fragments and Maxam-Gilbert gel methods of sequence analysis, we have determined the preferred binding sites o...

Derivation of the bamhIR sequence (Brooks, J. E., Nathan, P.D., Landry, D., Sznyter, L.A., Waite-Rees, P., Ives, C. C., Mazzola, L. M., Slatko, B. E., and Benner, J. S. (1991) Nucleic Acids Res., in press), the gene coding for BamHI endonuclease, has facilitated construction of an Escherichia coli strain that overproduces BamHI endonuclease (W. E. Jack, L. Greenough, L. F. Dorner, S. Y. Xu, T. ...

The interaction of simple and ternary Cu(II) complexes of 1,10-phenanthrolines with DNA has been studied extensively because of their various interesting and important functions such as DNA cleavage activity, cytotoxicity towards cancer cells, and DNA based asymmetric catalysis. Such functions are closely related to the DNA binding modes of the complexes such as intercalation, groove binding, a...

Type IIA topoisomerases control DNA supercoiling and separate newly replicated chromosomes using a complex DNA strand cleavage and passage mechanism. Structural and biochemical studies have shown that these enzymes sharply bend DNA by as much as 150°; an invariant isoleucine, which has been seen structurally to intercalate between two base pairs outside of the DNA cleavage site, has been sugges...

Type IA topoisomerase activities are essential for resolving DNA topological barriers via an enzyme-mediated transient single strand DNA break. Accumulation of topoisomerase DNA cleavage product can lead to cell death or genomic rearrangement. Many antibacterial and anticancer drugs act as topoisomerase poison inhibitors that form stabilized ternary complexes with the topoisomerase covalent int...

The bleomycins (BLMs) are a family of natural glycopeptides used clinically as antitumor agents. In the presence of required cofactors (Fe(2+) and O(2)), BLM causes both single-stranded (ss) and double-stranded (ds) DNA damage with the latter thought to be the major source of cytotoxicity. Previous biochemical and structural studies have demonstrated that BLM can mediate ss cleavage through mul...