Structural study of the higher order chromatin structure formed by HP1BP3

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06692
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Structural biochemistry
• Research Institution: Waseda University
• Principal Investigator: Koyama Masako 早稲田大学, 理工学術院, 次席研究員(研究院助教) (40755097)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: クロマチン / ヌクレオソーム / 分裂酵母 / リンカーヒストン

Outline of Final Research Achievements

We have aimed to determine the structure of the fundamental unit of higher order chromatin formed by human HP1BP3, the recently identified linker histone in human. However, it was difficult to purify the HP1BP3 protein at high yield necessary for the structural studies. Therefore, we selected the functional homolog of HP1BP3 in S. pombe. The protein was expressed as a soluble recombinant protein in E. coli, and purified in high quality. Furthermore, we established the method to reconstitute S. pombe nucleosomes in vitro. We purified the four canonical core histones in S. pombe (H2A, H2B, H3, and H4, which share 79%, 68%, 92%, and 91% amino acid sequence homology with their human counterparts). Using S. pombe histones and a 146-base-pair DNA, we successfully reconstituted nucleosomes in vitro. We confirmed that the HP1BP3 homolog in S. pombe bind the nucleosome.

Free Research Field

クロマチンの構造生物学