Six novel copper(ii) complexes of [CuCl]ClO4 (), [Cu(acac)]PF6 (), [CuCl]2(PF6)2 (), [CuCl]2(PF6)2 (), [Cu(acac)]PF6 () and [Cu(acac)]PF6 (), ( = 1-naphthyl-N,N-[bis(2-pyridyl)methyl]amine, = R/S-1-naphthyl-N,N-[bis(2-pyridyl)methyl]ethanamine, acac = diacetone) were synthesized to serve as artificial nucleases. All complexes were structurally characterized using X-ray crystallography. The crys...

The smallest known DNA transposases are those from the IS200/IS605 family. Here we show how the interplay of protein and DNA activates TnpA, the Helicobacter pylori IS608 transposase, for catalysis. First, transposon end binding causes a conformational change that aligns catalytically important protein residues within the active site. Subsequent precise cleavage at the left and right ends, the ...

The ability of small molecules to perturb the natural structure and dynamics of nucleic acids is intriguing and has potential applications in cancer therapeutics. This work reports the synthesis, characterization, cytotoxicity and DNA-binding studies of two cytotoxic and intercalative [M(bpy)(pyrr-dtc)]NO3 complexes (where M = Pt(II) and Pd(II), bpy = 2,2´-bipyridine and pyrr-dtc = p...

Porophyrins and their metal derivatives are strong DNA binders with association constant of  to  . Some of these compounds have been used for the radiations sensitization therapy of cancer and are targeted to interact with cellular DNA. Binding of porphyrins to DNA changes the expectral and other physic chemical characteristic of porphyrins, The mode of binding can be extracted from inspection ...

With the goal of developing artificial nucleases for DNA hydrolysis, metal-coordinating peptides have been tethered to a DNA-intercalating rhodium complex to deliver metal ions to the sugar-phosphate backbone. The intercalator, [Rh(phi)(2)bpy']Cl(3) [phi = 9,10-phenanthrenequinone diimine; bpy' = 4-(butyric acid)-4'-methyl-2,2'-bipyridine], provides DNA binding affinity, and a metal-binding pep...

Human tyrosyl-DNA phosphodiesterase (Tdp1) processes 3'-blocking lesions, predominantly 3'-phosphotyrosyl bonds resulting from the trapping of topoisomerase I (Top1) cleavage complexes. The controversial ability of yeast Tdp1 to hydrolyze 5'-phosphotyrosyl linkage between topoisomerase II (Top2) and DNA raises the question whether human Tdp1 possesses 5'-end processing activity. Here we charact...

The mechanisms controlling progression of conjugative DNA processing from a preinitiation stage of specific plasmid strand cleavage at the transfer origin to a stage competent for unwinding the DNA strand destined for transfer remain obscure. Linear heteroduplex substrates containing double-stranded DNA binding sites for plasmid R1 relaxosome proteins and various regions of open duplex for TraI...

AbaSI, a member of the PvuRts1I-family of modification-dependent restriction endonucleases, cleaves deoxyribonucleic acid (DNA) containing 5-hydroxymethylctosine (5hmC) and glucosylated 5hmC (g5hmC), but not DNA containing unmodified cytosine. AbaSI has been used as a tool for mapping the genomic locations of 5hmC, an important epigenetic modification in the DNA of higher organisms. Here we rep...

McrBC is a methylation-dependent endonuclease from Escherichia coli K-12. The enzyme recognizes DNA with modified cytosines preceded by a purine. McrBC restricts DNA that contains at least two methylated recognition sites separated by 40-80 bp. Two gene products, McrBL and McrBs, are produced from the mcrB gene and one, McrC, from the mcrC gene. DNA cleavage in vitro requires McrBL, McrC, GTP a...

The sequence selectivity of DNase 1 cleavage has been investigated by site-directed mutagenesis of a chemically synthesised gene. Two key DNA binding residues have been conservatively altered (Y76F and R41K) or have had their side-chains truncated (Y76A and R41A) and the effect on the cleavage of tyr T promoter DNA has been noted. It would appear from these studies that DNase 1 is not sensitive...