7pf2
From Proteopedia
Nucleosome stack of the 4x187 nucleosome array containing H1
Structural highlights
Function[H14_HUMAN] Histone H1 protein binds to linker DNA between nucleosomes forming the macromolecular structure known as the chromatin fiber. Histones H1 are necessary for the condensation of nucleosome chains into higher-order structured fibers. Acts also as a regulator of individual gene transcription through chromatin remodeling, nucleosome spacing and DNA methylation (By similarity). Publication Abstract from PubMedThroughout the genome, nucleosomes often form regular arrays that differ in nucleosome repeat length (NRL), occupancy of linker histone H1 and transcriptional activity. Here, we report cryo-EM structures of human H1-containing tetranucleosome arrays with four physiologically relevant NRLs. The structures show a zig-zag arrangement of nucleosomes, with nucleosomes 1 and 3 forming a stack. H1 binding to stacked nucleosomes depends on the NRL, whereas H1 always binds to the non-stacked nucleosomes 2 and 4. Short NRLs lead to altered trajectories of linker DNA, and these altered trajectories sterically impair H1 binding to the stacked nucleosomes in our structures. As the NRL increases, linker DNA trajectories relax, enabling H1 contacts and binding. Our results provide an explanation for why arrays with short NRLs are depleted of H1 and suited for transcription, whereas arrays with long NRLs show full H1 occupancy and can form transcriptionally silent heterochromatin regions. Histone H1 binding to nucleosome arrays depends on linker DNA length and trajectory.,Dombrowski M, Engeholm M, Dienemann C, Dodonova S, Cramer P Nat Struct Mol Biol. 2022 May;29(5):493-501. doi: 10.1038/s41594-022-00768-w., Epub 2022 May 17. PMID:35581345[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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