Histone Fold
Histone Fold - Related Videos
02:30
Histone Variants at the Centromere
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2020
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:32
Histone Modification
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2020
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression. Acetylation The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
09:47
Analysis of Histone Antibody Specificity with Peptide Microarrays
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Cited by 22 •
2017
This manuscript describes methods for applying peptide microarray technology to specificity profiling of antibodies that recognize histones and their post-translational modifications.
03:00
Molecular Chaperones and Protein Folding
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2020
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein. The...
01:49
Protein Folding
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2020
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation which is critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.Protein Structure Is Critical to Its Biological FunctionProteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
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Hydrophobic and charged surfaces complement one another at the protein interface. Hydrophobic contacts help exclude unfavorable interactions with the surrounding environment, while charged regions contribute specific electrostatic contacts between partner proteins. Together, these features support stable H3-H4 and H2A-H2B dimers, providing the protein framework required for nucleosome core assembly and DNA organization.
The central beta hairpin helps organize the three-alpha-helix motif and the two connecting loops into a compact interaction surface. This arrangement gives the fold a defined geometry for contacting another protein. Its contribution is therefore structural rather than merely decorative, because the overall architecture supports the precise dimerization required in histone-based chromatin packaging.
H3-H4 and H2A-H2B are distinct histone dimers that assemble together into the nucleosome core. The histone fold enables the protein-protein contacts that hold each dimer together and allow these components to participate in a larger complex. Once assembled, the core provides the structure around which DNA wraps, producing compact chromatin.
A conserved fold preserves a molecular framework for recurring histone interactions across chromatin-related systems. This makes the motif useful for studying how histone variants may affect nucleosome organization and how chromatin remodeling changes DNA accessibility or structure. Its conservation also connects structural protein interactions with broader processes such as transcriptional regulation and DNA repair.
An analysis would examine the three alpha helices, the connecting loops, the central beta hairpin, and the hydrophobic and charged surfaces that support dimer formation. Researchers can then relate these structural features to H3-H4 or H2A-H2B assembly and to nucleosome organization. This approach links molecular architecture with the biological behavior of chromatin.
Its contribution begins with dimer formation, which supplies organized protein components for building the nucleosome core. DNA wraps around that core, allowing genetic material to occupy less space as chromatin. This packaging is not only structural: the resulting chromatin organization also provides a context for transcriptional regulation and the maintenance of epigenetic information.
The fold helps assemble the nucleosome-based chromatin framework in which regulatory information is organized. Because nucleosomes package DNA and participate in chromatin structure, changes involving histone variants or chromatin remodeling can be studied in relation to transcriptional regulation. The same framework is relevant to epigenetic inheritance, where chromatin-associated information is maintained across cellular contexts.