Background
The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries. H2A histone family member X (usually abbreviated as H2A.x) is a type of histone protein from the H2A family encoded by the H2AFX gene. H2A.x contributes to nucleosome-formation, chromatinremodeling and DNA repair, and is also used in vitro as an assay for double-strand breaks in dsDNA.
Cellular location
Nucleus