Chromatin Remodeling and Histone Modifications
DNA is compacted, folded and organized within chromatin in the nuclei of eukaryotic cells. As the fundamental subunit of chromatin, nucleosomes form a chain of small ellipsoidal beads of histone proteins around which the DNA is circumscribed. Four histones (H2A, H2B, H3, and H4) form the octamer center of the nucleosome with 146 nucleotide pairs wrapped around the center 1¾ turns. Each histone has an amino-terminal tail region consisting of 25-40 amino acid residues that protrude beyond the nucleosome surface. H1 histone plays a role in linking the nucleosome structures together to condense chromatin.
Current topics in histone modification
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