Histone Isoforms

Histone isoforms are expressed only in S-phase of the cell cycle and therefore referred as replication-dependent histones. These are found in numerous clusters with multiple histone genes differing in one of few amino acids. This class of histone gene has a short highly conserved stem-loop structure in their 3′ untranslated region.

Types of histone isoforms Histone H2A, Histone H2B, Histone H3, Histone H4