Histones are a group of proteins characterized by high levels of lysine and arginine that form reversible complexes with DNA. Based on the fractions, the molar mass of histones varies between 11-21kDa. Five different fractions have been isolated and characterized. They include H1 (lysine rich), H2a and H2b that are slightly lysine rich, H3 and H4 that are arginine rich. H1 acts as a link between "beads" (nu bodies) on the chromatin chain.
