Histone

Histones are proteins that are found to be associated with eukaryotic DNA. There are five histone types known (H1, H2A, H2B, H3 and H4). Two of each H2A, H2B, H3 and H4 are assembled to form a nucleosome together with DNA, thereby packing it tight. H1 is needed for histone-DNA-complexes to form a 30-nm-fiber, which packs the DNA even more tight. In general, genes that are active have less histones, while inactive genes are highly associated with histones during interphase?.

See also : genetics