Histone Variant

**Semantic type:** Classification

**Definition:** A family of proteins that can substitute for the core canonical histones (H3, H4, H2A, H2B) in nucleosomes. Unlike canonical core histones, variant histones may be expressed during the entire cell cycle and the genes encoding histone variants usually are found outside histone gene clusters, contain introns and their transcribed mRNAs have a polyadenine tail.

**Synonyms:** - histone variant - histone_variant