The eukaryotic genome is extraordinarily well organized. This is achieved through the winding of DNA to form continuous arrays of nucleosome, the fundamental repeating unit of chromatin. Each nucleosome consists of ~147 base pairs of DNA wrapped around a core histone octamer (two copies each of histone H2A, H2B, H3, and H4). Based on this, by the association with linker histones (histone H1), the nucleosome arrays are further organized into solenoid conformation and looping domain structures that occur in both interphase and metaphase chromatin. During cell division, global histone protein production is temporally elevated to meet the cellular demands since histone proteins are needed to be deposited into the newly replicated DNA strands before chromatin condensation and chromatids segregation could happen, which subsequently divided the genetic materials into daughter cells.
In the past half century, histone proteins have long been regarded as the bulk materials...