Browsed by
Month: January 2014

Topo I and Cobalt Complex

Topo I and Cobalt Complex

Revealing new paper on metallo-inhibitors. Article Source: Science Direct Synthesis and structure elucidation of a cobalt(II) complex as topoisomerase I inhibitor: In vitro DNA binding, nuclease and RBC hemolysis Abstract Metal-based cancer chemotherapeutic agent of the type Co(II) complex [Co(mpca)2]·H2O (1), where, Hmpca = 9-methyl-[1,10]phenanthroline-2-carboxylic acid was synthesized and characterized by various spectroscopic and analytical techniques and further authenticated by single crystal X-ray diffraction methods. In vitro DNA binding studies of complex 1 with CT DNA was carried out by…

Read More Read More

Supercoiling DNA with Reverse Gyrase

Supercoiling DNA with Reverse Gyrase

A new reverse gyrase from Pyrobaculum species has been identified with some novel properties. It combines helicase with topoisomerase domains. Very interesting from an evolutionary perspective. Article Source: The Journal of Biological Chemistry The reverse gyrase form Pyrobaculum calidifontis, a novel extremely thermophilic DNA topoisomerase endowed with DNA unwinding and annealing activities Abstract Reverse gyrase is a DNA topoisomerase specific of hyperthermophilic bacteria and archaea. It catalyses the peculiar ATP-dependent DNA positive supercoiling reaction and might be involved in the…

Read More Read More

Topoisomerase II Targeting and Resveratrol

Topoisomerase II Targeting and Resveratrol

In this paper the authors use a decatenation assay to identify some new topoisomerase II inhibitors from resveratrol. kDNA substrate was provided by TopoGEN. Article Source: Journal of Agricultural and Food Chemistry Topoisomerase II-Targeting Properties of a Grapevine-Shoot Extract and Resveratrol Oligomers Abstract Grapevine-shoot extracts (GSE), containing trans-resveratrol and resveratrol oligomers, are commercially available as food supplements. Considering the topoisomerase-targeting properties of trans-resveratrol, the question of whether GSE affect these enzymes, thereby potentially causing DNA damage, was addressed. In a…

Read More Read More

Topoisomerase Inhibition and Torsional Stress

Topoisomerase Inhibition and Torsional Stress

Topology is critical in allowing chromatin to function in a normal manner. DNA templating is clearly impacted when enzymes that relieve strain are blocked in a chromatin context. Specifically, inhibition of topoisomerases leads to rapid accumulation of torsional strain accompanied by changes in Pol II kinetics and destabilization of nucleosomes. Transcription-generated torsional stress destabilizes nucleosomes Article Source: Nature Abstract As RNA polymerase II (Pol II) transcribes a gene, it encounters an array of well-ordered nucleosomes. How it traverses through this…

Read More Read More

Embryogenesis and Topo I: Screening for Cheaters

Embryogenesis and Topo I: Screening for Cheaters

The authors have used a clever genetic screen to identify “Cheater mutations” in genes that confer the ability of cells to behave in a non-cooperative fashion in a tissue context. These cheater cells could for example, outgrow surrounding cells as aberrant clones, and thereby derail a tightly regulated process of differentiation that is pivotal in development. A very nice bioinformatic rendering of the data revealed that an axis of regulatory genes that are under the influence of topoisomerase I and…

Read More Read More