Common Histone H4

Histone H4 is one of the five main histone proteins involved in the structure of chromatin in eukaryotic cells. Featuring a main globular domain and a long N-terminal tail, H4 is involved with the structure of the nucleosome of the 'beads on a string' organization. Histone H4 is an important protein in the structure and function of chromatin, where its sequence variants and variable modification states are thought to play a role in the dynamic and long-term regulation of genes.

Histone H4 is a 102 to 135 amino acid protein which shares a structural motif, known as the histone fold, formed from three a-helices connected by two loops. Histone proteins H3 and H4 bind to form an H3-H4 dimer, two of these H3-H4 dimers combine to form a tetramer. This tetramer further combines with two H2a-H2b dimers to form the compact Histone octamer core.

Histone methylation occurs on arginine, lysine and histidine amino acids residues. Mono-, di- or tri-methylation has been discovered on histone H2A, H3 and H4. Histone methylation has been associated with various cellular functions such as transcription, DNA replication, and DNA damage response including repair, heterochromatin formation, and somatic cell reprogramming. Also methylation of histone H4 by PRMT1 was sufficient to permit subsequent acetylation on the N-terminal tail. However, acetylation of H4 inhibits its methylation by PRMT1, such as H4K20me2.

Acetylation of histones is thought to relax condensed heterochromatin as the negative charge of acetyl groups can repel the DNA phosphate backbone charges, thus reducing the histone binding affinity for DNA. We can provide H4K5ac, H4K8ac, H4K12ac, H4K16ac, H4K20ac.