A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.

Major protein component of chromatin. Highly conserved basic proteins, originally classified into classes based on the relative amounts of arginine and lysine in each protein. The various classes are now termed H1, H2A, H2B, H3, and H4. In chromatin, they are found in an octamer, containing two each of H2A, H2B, H3, and H4, complexed with DNA in nucleosomes. The histones in the octamer complex are also known as the core histones. The H1 class of histones, termed the linker histones, is loosely associated with the nucleosome.

Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.

Histone, any of a group of simple alkaline proteins usually occurring in cell nuclei, combined ionically with DNA (deoxyribonucleic acid) to form nucleoproteins. A unit in which a molecule of a histone is bound to a segment of the DNA chain of genetic material is termed a nucleosome...