Structure et dynamique de la particule coeur de nucléosome

Abstract

In eukaryotic cell, a few meters of DNA are compacted in nuclear compartment of a few microns. This high level of compaction is an important way to regulate gene expression. In the present paper, we present a description of the organization of DNA into its first level of compaction: the nucleosome core particle. The structure of the nucleosome has been described at an atomic resolution more than 10 years ago, where DNA is wrapped around an octamer of histones. Post-translational modifications affecting histone tails have been shown to regulate the chromatin degree of compaction and thus the gene expression and regulation. The structure of the NCP is far from being frozen and is highly dynamic. Remodeling factors can induce DNA sliding around the histones, DNA transaction processes such as transcription and replication.