Histone H2A

Histone H2A is one of the 5 main histone proteins involved in the structure of chromatin in eukaryotic cells. Featuring a main globular domain and a long N terminal tail, H2A is involved with the structure of the nucleosomes of the 'beads on a string' structure.

Other histone proteins involved: H1 H2B H3 H4

Sequence Variants
The term "Histone H2A" is intentionally non-specific and refers to a variety of closely related proteins that vary often by only a few amino acids. Notable variants include H2A.1, H2A.2, H2A.X, and H2A.Z.

Genetics
H2A is coded by many genes in the human genome, including:

H2AFB1, H2AFB2, H2AFB3, H2AFJ, H2AFV, H2AFX, H2AFY, H2AFY2, and H2AFZ