| Literature DB >> 31711756 |
Yoshimasa Takizawa1, Cheng-Han Ho2, Hiroaki Tachiwana3, Hideyuki Matsunami4, Wataru Kobayashi5, Midori Suzuki6, Yasuhiro Arimura7, Tetsuya Hori8, Tatsuo Fukagawa8, Melanie D Ohi9, Matthias Wolf10, Hitoshi Kurumizaka11.
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.Entities:
Keywords: CENP-A; centromere; chromatin; cryo-EM; histone variant; nucleosome
Year: 2019 PMID： 31711756 DOI： 10.1016/j.str.2019.10.016
Source DB: PubMed Journal: Structure ISSN： 0969-2126 Impact factor: 5.006