Histone H3 is a core histone protein critical in organizing DNA into chromatin. It is a highly conserved protein across species and has structural features that contribute to its functions in chromatin packaging and gene regulation. Histone H3 consists of a structured histone fold domain and N-terminal tail. The histone fold domain is a globular structure that forms the histone octamer core when H3 interacts with its partner histones, H2A, H2B, and H4, in the nucleosome. The histone fold domain is composed of three alpha helices separated by two loops, a common feature amongst core histones. The N-terminal tail of histone H3 is unstructured, protruding from the nucleosome core. It is rich in lysine and arginine residues which can be post-translationally modified by methylation, acetylation, phosphorylation and ubiquitylation. Histone H3, along with its partner histones (H2A, H2B, and H4), contributes to the formation of the histone octamer core within the nucleosome. This core structure acts as a scaffold around which DNA is wrapped, compacting the DNA double helix into a chromatin fibre. The interactions between histone H3 and DNA are therefore essential for maintaining the stability of the nucleosome. Like the other core histones, histone H3 plays a critical role in chromatin compaction by contributing to the folding of DNA into higher-order structures, leading to chromatin compaction within the nucleus. The degree of such chromatin compaction can be modulated through the various post-translational modifications on histone H3 and other histones. Histone H3 is a major target for these various post-translational modifications that can regulate chromatin structure and gene expression. For example, acetylation of specific lysine residues on histone H3 is associated with gene activation, whilst methylation can have varying effects on gene expression depending on the specific context and site of modification. Histone H3 modifications are intimately involved in transcriptional regulation with specific modifications acting as recognition signals for the recruitment of transcriptional activators or repressors. These modifications can either promote or inhibit gene expression by altering chromatin accessibility and the binding of transcription factors to DNA. Histone H3 variants, such as H3.3 and CENP-A, play critical roles in chromatin remodelling. H3.3 is involved in dynamic nucleosome turnover and histone replacement, particularly in the context of transcription and DNA repair, whilst CENP-A is a variant of histone H3 that is specifically associated with centromeric chromatin and plays a role in chromosome segregation during cell division. Histone H3 is also associated with DNA repair processes. Upon DNA damage, specific histone H3 variants such as H3.3, are incorporated into sites of repair to facilitate the recruitment of DNA repair factors. Additionally, histone modifications on H3 can mark such DNA damaged sites thereby promoting repair processes. During cell division, histone H3 undergoes extensive phosphorylation, contributing to mitotic chromosome condensation. This phosphorylation results in chromatin compaction, ensuring the proper segregation of chromosomes during mitosis. Thus, histone H3 is a core histone protein with a structured histone fold domain and an N-terminal tail which plays a central role in chromatin structure and gene regulation. We offer a large product range of research tools for investigating Histone H3, including Histone H3 antibodies, and PRDM9 antibodies. Explore our full Histone H3 product range below and discover more, for less. Alternatively, you can explore our Phosphorylated, Methylated, and Acetylated product ranges.