Eukaryotic DNA is packaged, protected, and regulated by a histone protein core, around which the DNA is wrapped. This structure, termed chromatin, can be condensed and “closed,” a state associated with relative transcriptional repression. Conversely, chromatin can be “open,” a state which allows proteins governing transcription to access the DNA and effect RNA synthesis. Regulation of chromatin...

We conducted molecular dynamics computer simulations of charged histone tail-DNA interactions in systems mimicking nucleosome core particles (NCP) . In a coarse-grained model, the NCP is modeled as a negatively charged spherical particle with flexible polycationic histone tails attached to it in a dielectric continuum with explicit mobile counterions and added salt. The size, charge, and distri...

The Histone Database (HDB) is an annotated and searchable collection of all full-length sequences and structures of histone and non-histone proteins containing the histone fold motif. These sequences are both eukaryotic and archaeal in origin. Several new histone fold-containing proteins have been identified, including Spt7p, and a few false positives have been removed from the earlier version ...

Chromatin assembly involves the combined action of histone chaperones and ATP-dependent motor proteins. Here, we investigate the mechanism of nucleosome assembly with a purified chromatin assembly system containing the histone chaperone NAP1 and the ATP-dependent motor protein ACF. These studies revealed the rapid formation of a stable nonnucleosomal histone-DNA intermediate that is converted i...

Pesticide exposure has been implicated in the etiopathogenesis of Parkinson's disease (PD); in particular, the organochlorine insecticide dieldrin is believed to be associated with PD. Emerging evidence indicates that histone modifications play a critical role in cell death. In this study, we examined the effects of dieldrin treatment on histone acetylation and its role in dieldrin-induced apop...

The importance of control of the levels of histone acetylation for the control of gene expression in eukaryotic chromatin is being elucidated, and the yeast Saccharomyces cerevisiae has proven to be an important model system. The level of histone acetylation in yeast is the highest known. However, only acetylation of H4 has been quantified, and reports reveal loss of acetylation in histone prep...

A wide variety of histone-like proteins can be assembled into nucleosomal structures. Core and linker histone variants, proteins of the histone-fold and winged-helix families can all contribute to the local differentiation of functional chromosomal domains. It is very difficult to disrupt core histone interactions within a nucleosome in vivo. Histones H3 and H4 do not exchange out of chromatin ...