6L4A

H3-H3-H3 tri-nucleosome with the 22 base-pair linker DNA

Summary for 6L4A

• Entry DOI: 10.2210/pdb6l4a/pdb
• EMDB information: 0770
• Descriptor: Histone H3.1, Histone H4, Histone H2A type 1-B/E, ... (6 entities in total)
• Functional Keywords: chromatin, nucleosome, centromere, nuclear protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 26
• Total formula weight: 635984.96

Authors

Takizawa, Y.,Ho, C.-H.,Tachiwana, H.,Matsunami, H.,Ohi, M.,Wolf, M.,Kurumizaka, H. (deposition date: 2019-10-16, release date: 2019-12-04, Last modification date: 2024-03-27)

Primary citation

Takizawa, Y.,Ho, C.H.,Tachiwana, H.,Matsunami, H.,Kobayashi, W.,Suzuki, M.,Arimura, Y.,Hori, T.,Fukagawa, T.,Ohi, M.D.,Wolf, M.,Kurumizaka, H.
Cryo-EM Structures of Centromeric Tri-nucleosomes Containing a Central CENP-A Nucleosome.
Structure, 28:44-, 2020

PubMed Abstract: The histone H3 variant CENP-A is a crucial epigenetic marker for centromere specification. CENP-A forms a characteristic nucleosome and dictates the higher-order configuration of centromeric chromatin. However, little is known about how the CENP-A nucleosome affects the architecture of centromeric chromatin. In this study, we reconstituted tri-nucleosomes mimicking a centromeric nucleosome arrangement containing the CENP-A nucleosome, and determined their 3D structures by cryoelectron microscopy. The H3-CENP-A-H3 tri-nucleosomes adopt an untwisted architecture, with an outward-facing linker DNA path between nucleosomes. This is distinct from the H3-H3-H3 tri-nucleosome architecture, with an inward-facing DNA path. Intriguingly, the untwisted architecture may allow the CENP-A nucleosome to be exposed to the solvent in the condensed chromatin model. These results provide a structural basis for understanding the 3D configuration of CENP-A-containing chromatin, and may explain how centromeric proteins can specifically target the CENP-A nucleosomes buried in robust amounts of H3 nucleosomes in centromeres.

PubMed: 31711756
DOI: 10.1016/j.str.2019.10.016

Experimental method

ELECTRON MICROSCOPY (12.3 Å)