Histone H3 combines with Histone H4 to form the H3/H4 tetramer. Two H2A/H2B heterodimers interact with an H3/H4 tetramer to form the histone octamer (1,2). It is also modified by various enzymes and can act as a substrate for them. These modifications have been shown to be important in gene reg4ation.
View Histone H3.1 Human, Recombinant on New England Biolabs’s website- Histone H3.1 Human, Recombinant