Crystal structure of the overlapping dinucleosome composed of hexasome and octasome

• Published in: Science (American Association for the Advancement of Science) Vol. 356; no. 6334; pp. 205 - 208
• Main Authors: Kato, Daiki, Osakabe, Akihisa, Arimura, Yasuhiro, Mizukami, Yuka, Horikoshi, Naoki, Saikusa, Kazumi, Akashi, Satoko, Nishimura, Yoshifumi, Park, Sam-Yong, Nogami, Jumpei, Maehara, Kazumitsu, Ohkawa, Yasuyuki, Matsumoto, Atsushi, Kono, Hidetoshi, Inoue, Rintaro, Sugiyama, Masaaki, Kurumizaka, Hitoshi
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 14-04-2017; The American Association for the Advancement of Science
• Subjects: Base pairs; Chromatin; Chromatin remodeling; Contact; Crystal structure; Crystallography, X-Ray; Deoxyribonucleic acid; Dimers; DNA; DNA - chemistry; DNA - ultrastructure; Handedness; Histones; Histones - chemistry; Histones - genetics; Histones - ultrastructure; Humans; Mutation; Nuclei; Nucleosomes; Nucleosomes - genetics; Nucleosomes - ultrastructure; Packaging; Protein Multimerization; Proteins; Remodeling; Replication; Segments; Sucrose; Sugar; Transcription
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aak9867

Nucleosomes are dynamic entities that are repositioned along DNA by chromatin remodeling processes. A nucleosome repositioned by the switch-sucrose nonfermentable (SWI/SNF) remodeler collides with a neighbor and forms the intermediate “overlapping dinucleosome.” Here, we report the crystal structure of the overlapping dinucleosome, in which two nucleosomes are associated, at 3.14-angstrom resolution. In the overlapping dinucleosome structure, the unusual “hexasome” nucleosome, composed of the histone hexamer lacking one H2A-H2B dimer from the conventional histone octamer, contacts the canonical “octasome” nucleosome, and they intimately associate. Consequently, about 250 base pairs of DNA are left-handedly wrapped in three turns, without a linker DNA segment between the hexasome and octasome moieties. The overlapping dinucleosome structure may provide important information to understand how nucleosome repositioning occurs during the chromatin remodeling process.