**Heterotypic [H3 • H3K4me3] Recombinant Nucleosome, Biotinylated, 25 µg

Datasheet

Heterotypic nucleosomes, also referred to as “asymmetric nucleosomes,” contain sister histones with distinct histone variants and/or post-translational modifications (PTMs). In homotypic nucleosomes, or “symmetric nucleosomes,” each pair of sister histones bears the same PTM, set of PTMs, or histone variant. Histone-modifying enzymes, chromatin remodelers, and histone chaperones differentially modify sister histones or exchange unique histone variants to form heterotypic nucleosomes. Heterotypic nucleosomes have been found at promoters of developmental genes in undifferentiated embryonic stem cells and transcription start sites (TSSs) of approximately half of the genes in budding yeast. Heterotypic nucleosomes represent an additional layer of the histone code, acting as substrates for multivalent reader proteins, participating in PTM crosstalk mechanisms, and influencing reader protein binding affinity through varying local target concentration. Recombinant heterotypic nucleosomes are useful for studying chromatin dynamics and transcriptional regulation. Heterotypic [H3 • H3K4me3] Recombinant Nucleosome, Biotinylated is a fully defined semi-synthetic nucleosome containing one unmodified histone H3 and one histone H3 with trimethylated lysine at position four. [H3 • H3K4me3] nucleosome consists of 147 base pairs of 601 sequence DNA wrapped around an octamer of core histone proteins (two each of H2A, H2B, H3.2, and H4) to form a nucleosome, the basic repeating unit of chromatin. The DNA contains a 5’ biotin-TEG group, and histone H3.2 has a Cys to Ala substitution at position 110. Heterotypic [H3 • H3K4me3] nucleosomes fail to recruit known H3K4me3 binding proteins, including members of the TFIID, SETD1, and SIN3A/B complexes; chromatin remodelers NURF, CHD1, and CHD8; and PHD finger protein PHF2, suggesting that heterotypic nucleosomes may regulate transcription by affecting the recruitment of various chromatin regulatory complexes.