• binds
  • The linker histone H1 binds the nucleosome at the entry and exit sites of the DNA, thus locking the DNA into place and allowing the formation of higher order structure. (wikipedia.org)
  • It is responsible for most of the cytoplasmic HAT activity in yeast, and it binds strongly to histone H4 by virtue of its association with an additional subunit, Hat2. (wikipedia.org)
  • To facilitate this formation, histone H2B first binds to histone H2A to form a heterodimer. (wikipedia.org)
  • enzymes
  • Histone deacetylases (EC 3.5.1.98, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on a histone, allowing the histones to wrap the DNA more tightly. (wikipedia.org)
  • HDACs, are classified in four classes depending on sequence homology to the yeast original enzymes and domain organization: HDAC (except class III) contain zinc and are known as Zn-dependent histone deacetylases. (wikipedia.org)
  • The figure on the right enlists those histone-modifying enzymes whose specificity has been determined. (wikipedia.org)
  • variant
  • changes in variant composition were seen among the H2A.1 histone. (wikipedia.org)
  • Other functions of H2A have been seen in the histone variant H2A.Z. This variant is associated with gene activation, silencing and suppression of antisense RNA. (wikipedia.org)
  • In vertebrates and invertebrates, Histone H2A variant is reported to be involved in host immune response by acting as antimicrobial peptides (AMPs). (wikipedia.org)
  • The core of the database is a manually curated set of histone sequences grouped into 30 different variant subsets with variant-specific annotations. (wikipedia.org)
  • classification of histone-like sequences and browsing of the taxonomic diversity for every histone variant. (wikipedia.org)
  • structurally
  • According to this nomenclature, letter suffixes or prefixes are mainly used to denote structurally distinct monophyletic clades of a histone family (e.g. (wikipedia.org)
  • A number of structurally diverse histone deacetylase inhibitors have shown potent antitumor efficacy with little toxicity in vivo in animal models. (wikipedia.org)
  • modifications
  • The hypothesis is that chromatin-DNA interactions are guided by combinations of histone modifications. (wikipedia.org)
  • Phosphorylation Ubiquitination However, there are many more histone modifications, and sensitive mass spectrometry approaches have recently greatly expanded the catalog. (wikipedia.org)
  • each of the four standard histones can be simultaneously modified at multiple different sites with multiple different modifications. (wikipedia.org)
  • Every nucleosome in a cell can therefore have a different set of modifications, raising the question of whether common patterns of histone modifications exist. (wikipedia.org)
  • A recent study of about 40 histone modifications across human gene promoters found over 4000 different combinations used, over 3000 occurring at only a single promoter. (wikipedia.org)
  • There are at least eight distinct types of modifications found on histones (see the legend box on the top left of the figure). (wikipedia.org)
  • chromosomes
  • Without histones, the unwound DNA in chromosomes would be very long (a length to width ratio of more than 10 million to 1 in human DNA). (wikipedia.org)
  • In Xenopus egg extracts, linker histone depletion causes ~2-fold lengthwise extension of mitotic chromosomes, while overexpression causes chromosomes to hypercompact into an inseparable mass. (wikipedia.org)