6t93
From Proteopedia
Nucleosome with OCT4-SOX2 motif at SHL-6
Structural highlights
Function[H2B1J_HUMAN] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.[1] [2] [3] Has broad antibacterial activity. May contribute to the formation of the functional antimicrobial barrier of the colonic epithelium, and to the bactericidal activity of amniotic fluid.[4] [5] [6] Publication Abstract from PubMedTranscription factors (TFs) regulate gene expression through chromatin where nucleosomes restrict DNA access. To study how TFs bind nucleosome-occupied motifs we focused on the reprogramming factors OCT4 and SOX2. We determined TF engagement throughout a nucleosome at base-pair resolution in vitro, enabling cryo-EM structure determination at two preferred positions. Depending on motif location, OCT4-SOX2 differentially distort nucleosomal DNA. At one position, OCT4-SOX2 removes DNA from Histone H2A/Histone H3 (H2A/H3); however, at an inverted motif, the TFs only induce local DNA distortions. OCT4 uses one of its two DNA binding domains to engage DNA in both structures, reading-out a partial motif. These findings explain site specific nucleosome engagement by the pluripotency factors OCT4-SOX2 and reveal how TFs distort nucleosomes to access chromatinized motifs. Mechanisms of OCT4-SOX2 motif readout on nucleosomes.,Michael AK, Grand RS, Isbel L, Cavadini S, Kozicka Z, Kempf G, Bunker RD, Schenk AD, Graff-Meyer A, Pathare GR, Weiss J, Matsumoto S, Burger L, Schubeler D, Thoma NH Science. 2020 Apr 23. pii: science.abb0074. doi: 10.1126/science.abb0074. PMID:32327602[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Large Structures | Bunker, R D | Cavadini, S | Kempf, G | Michael, A K | Thoma, N H | Nucleosome | Oct4 | Sox2 | Transcription | Transcription factor
