2010 Fiscal Year Final Research Report
The structural analysis of centromere specific nucleosome
| Project/Area Number |
21870038
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| Research Category |
Grant-in-Aid for Research Activity Start-up
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| Allocation Type | Single-year Grants |
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| Research Field |
Biophysics
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| Research Institution | Waseda University |
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Principal Investigator |
TACHIWANA Hiroaki Waseda University, 理工学術院, 助教 (70546382)
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| Research Collaborator |
KURUMIZAKA HITOSHI 早稲田大学, 理工学術院, 教授 (80300870)
KAGAWA Wataru 早稲田大学, 理工学術院, 助教 (70415123)
KIMURA Hiroshi 大阪大学, 生命機能研究科, 准教授 (30241392)
PARK Sam-Yong 横浜市立大学, 教授 (20291932)
SATO Mamoru 横浜市立大学, 教授 (60170784)
SHIGA Tatsuya 早稲田大学, 大学院・先進理工学研究科, 修士2年
OSAKABE Akihisa 早稲田大学, 大学院・先進理工学研究科, 博士3年
MIYA Yuta 早稲田大学, 大学院・先進理工学研究科, 修士1年
MATSUMOTO Ryohei 早稲田大学, 大学院・先進理工学研究科, 修士1年
ARIMURA Yasuhiro 早稲田大学, 大学院・先進理工学研究科, 修士2年
HORIKOSHI Naoki 早稲田大学, 大学院・先進理工学研究科, 博士1年
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| Project Period (FY) |
2009 – 2010
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| Keywords | クロマチン / セントロメア / ヌクレオソーム / ヒストン / ヒストンバリアント |
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| Research Abstract |
In eukaryotes, genomic DNA is duplicated during S phase, and is equally divided into two daughter cells during M phase. Centromere, which is one of the distinct regions in chromosome, plays important rules in this division. Centromere formation is necessary for chromosome segregation. But, it is not known how centromere region is formed and distinguished from other region. Some proteins, which localize specifically at centromere region, are identified. CENP-A, a histone H3 variant, also localize specifically at centromere region. CENP-A is assembled into the chromatin of centromeres and is thought to generate unique chromatin features. In this study, we performed structural analysis of the CENP-A nucleosome and determined crystal structure of CENP-A nucleosome by X-ray crystallography. Determined structure revealed that CENP-A nucleosome contains two each of histones H2A, H2B, H4 and CENP-A and DNA is wrapped around histone octamer in a left-hand orientation. Surprisingly, only 121 bp of DNA are visible and 13 bp from both ends of DNA are flexible in the CENP-A-nucleosome. Structural comparison of the CENP-A and H3-nucleosomes revealed that the loop1 region of CENP-A is different from canonical H3 because of insertion of two extra amino acid residues. In vivo analysis revealed these amino acids are important to retain CENP-A at centromere region.
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