Histone H2A is a core histone protein that, together with H2B, H3, and H4, forms the structural framework of nucleosomes. As such, histone H2A plays essential roles in both chromatin structure and gene regulation. Histone H2A is a globular protein with a structured histone fold domain and a flexible N-terminal region. The histone fold domain is responsible for the formation of the histone octamer core in the nucleosome. It consists of three alpha-helices separated by two loops and is involved in protein-protein and protein-DNA interactions within the nucleosome. There are numerous variants of histone H2A, with each variant having specific roles and functions in chromatin regulation. For example, H2A.X is involved in DNA damage repair, H2A.Z is associated with transcriptional regulation, and macroH2A is implicated in gene silencing. These variants have distinct N-terminal tails and specific post-translational modifications, diversifying their functions. Histone H2A, along with other histones, is subject to various post-translational modifications, such as acetylation, methylation, phosphorylation, and ubiquitylation. These modifications can regulate chromatin structure and gene expression. For instance, acetylation of specific lysine residues on histone H2A is associated with gene activation, whilst methylation and ubiquitylation can have varying effects on gene expression depending on the specific context and site of modification. Histone H2A variants, such as H2A.X, are essential for DNA damage repair mechanisms. In response to DNA double-strand breaks, H2A.X is rapidly phosphorylated, leading to the recruitment of repair factors to the damaged site. This histone variant therefore serves as a marker for DNA damage and plays a role in the repair process. Certain other variants of histone H2A, like H2A.Z, are also associated with transcriptional regulation. H2A.Z is often found at the promoters and enhancers of actively transcribed genes. Its presence can either promote or inhibit transcription, depending on the specific context and the proteins it interacts with. Another variant, macroH2A, is associated with gene silencing. It is often found at heterochromatic regions and is involved in maintaining gene repression. The large macroH2A variant contains an additional domain that contributes to its role in gene silencing. Histone H2A, like other core histones, plays a crucial role in mitotic chromosome condensation. During cell division, histone H2A is extensively phosphorylated, leading to chromatin compaction and the formation of highly condensed chromosomes that can be properly segregated. Thus, histone H2A is a core histone protein that is integral to chromatin structure and gene regulation. Its structured histone fold domain, N-terminal tail, and various variants allow it to fulfil diverse functions in chromatin. Histone H2A contributes to nucleosome formation, chromatin compaction, epigenetic regulation, DNA repair, transcriptional regulation, gene silencing, and mitotic chromosome condensation. We offer a large product catalogue of research tools for investigating Histone H2a, including Histone H2A.X antibodies, and Histone H2A antibodies. Explore our full Histone H2a product range below and discover more, for less. Alternatively, you can explore our Unmodified, Acetylated, and Phosphorylated product ranges.