Histone H1, also known as the linker histone, is a key component of chromatin. Unlike the core histones (H2A, H2B, H3, and H4), which form the nucleosome core around which DNA is wrapped, histone H1 plays a distinct role in chromatin structure and organization. Histone H1 has a structured, globular domain at its core, which interacts with the DNA in the linker region between nucleosomes. This globular domain is often referred to as the winged helix domain due to its structural similarity to a winged helix-turn-helix DNA-binding motif. It consists of three alpha-helices and a pair of antiparallel beta-strands, forming a compact structure that can bind to DNA and contribute to chromatin compaction. At both ends of the globular domain, histone H1 has long, unstructured regions that extend beyond the nucleosome core. These regions are rich in lysine and arginine residues, which can be post-translationally modified, impacting the function of histone H1. The N-terminal tail can be acetylated or phosphorylated, whilst the C-terminal tail can be methylated, phosphorylated, or ubiquitylated. These modifications play a role in regulating the interactions of histone H1 with chromatin and other proteins. The primary function of histone H1 is in compaction of chromatin. Whilst the core histones package DNA into nucleosomes, histone H1 binds to the linker DNA between nucleosomes, helping to stabilize and condense the higher-order chromatin structure. This compaction is crucial for packaging the long DNA strands. When bound to chromatin, histone H1 can also restrict access to DNA, making it less accessible for transcription. Conversely, when histone H1 is absent or displaced from chromatin, gene transcription is often more active. The post-translational modifications on histone H1 tails affect its binding affinity to chromatin, contributing to the regulation of specific genes. Histone H1 has been implicated in the establishment of epigenetic marks, which are the heritable modifications of chromatin that regulate gene expression. It can interact with enzymes involved in both DNA methylation and histone modification, influencing the deposition of these marks and their propagation to daughter cells during cell division.Histone H1 also plays a role in DNA repair and recombination processes. Its ability to stabilize chromatin structure can aid in maintaining genome integrity. In certain repair pathways, histone H1 is removed or modified to facilitate access to damaged DNA sites, enabling repair factors to effectively repair DNA lesions. The levels and localization of histone H1 can vary throughout the cell cycle. During mitosis, histone H1 is phosphorylated, leading to its dissociation from chromatin and the condensation of chromosomes. This dynamic regulation of histone H1 helps coordinate chromosome condensation and segregation during cell division. Histone H1 isoforms and their post-translational modifications can vary in different cell types and during development. This variation contributes to cell-specific gene expression patterns and differentiation processes, ensuring that the right genes are expressed appropriately. We offer a wide product catalogue of research reagents for studying Histone H1, including Histone H1 antibodies. Explore our full Histone H1 product range below and discover more, for less. Alternatively, you can explore our Unmodified product range.