Presence of negative supercoiling in aggregates of histone H1-plasmidic polynucleosome complexes

Dataset on the effects of spermidine on linking number differences between histone H1-free and histone H1-bound circular polynucleosomes

The data presented in this article are related to the research article entitled "Quantitative determination of linking number differences between circular polynucleosomes and histone H1-bound circular polynucleosomes" Zhang et al. (in press) [1]. DNA linking number differences between histone H1-free and histone H1-bound circular polynucleosomes at various spermidine concentrations was quantitatively determined by chloroquine-based gel electrophoretic analysis in this work, which provides information on the topological effects of histone H1 and spermidine on the linker DNA between nucleosomes.

Effects of spermidine and ATP on stabilities of chromatosomes and histone H1-depleted chromatosomes

It is shown in our FRET studies that both chromatosomes and histone H1-depleted chromatosomes exist in their arm-closed forms in the absence of spermidine. In the presence of spermidine, however, these two types of structural assemblies are converted into their arm-open forms. In addition, ATP as polyanion is capable of suppressing the polycationic effect of spermidine, thus facilitating re-formation of arm-closed forms of these two types of structural assemblies. Our studies therefore illustrate that conversion between arm-closed and arm-open forms of chromatosomes and histone H1-depleted chromatosomes can be manipulated by varying concentrations of polycationic spermidine and polyanionic ATP.