Yawen Bai, Ph.D.
Laboratory of Biochemistry and Molecular Biology
Building 37, Room 6114E Bethesda, MD 20892-4260
Our long-term goal is to understand how DNA molecules in eukaryotic cells are folded to form various structures of chromatin, which is critical for the regulation of gene expression and cell function. The DNA molecules in eukaryotic cells are extremely long polymers that must be folded to more compact forms to fit within the small cell nucleus. A number of small positively charged proteins called histones help DNA fold. Core histones (H2A, H2B, H3, and H4) and DNA first form nucleosomes, the repeating structural unit of chromatin. Each nucleosome core particle contains two copies of each of the four core histones around which ~146 base pairs of DNA are wrapped. In higher-order eukaryotes, the repeating unit of chromatin is the chromatosome, which consists of one linker histone (H1) bound to linker DNA region of the nucleosome. Linker histones are responsible for the formation of more compact higher-order structures of chromatin and there are 11 linker histone variants in human. In addition, the dynamic folding/unfolding processes of chromatin are regulated by a large number of non-histone proteins including histone chaperones (Scm3/HJURP, Chz1….), chromatin remodeling enzymes (ISWI, SWI/SNF, INO80/SWR1, CHD1), histone modification enzymes (PRC1, PRC2…), pioneer transcription factors (Oct4, Sox2…), and kinetochore proteins (CENP-N, CENP-C). They play important roles in the regulation of cell function. We use biophysical techniques, in particular, the modern structural methods (NMR, X-ray crystallography and cryo-EM), to investigate the structural basis of the interactions between histones and their chaperones, (ii) the interactions between nucleosomes and nucleosome-binding proteins, (iii) chromatosome structures, and (iv) higher-order structures of chromatin.
Chittori S, Hong J, Bai Y, Subramaniam S. Structure of the primed state of the ATPase domain of chromatin remodeling factor ISWI bound to the nucleosome. Nucleic Acids Res. 2019;47(17):9400-9409.
Zhou BR, Jiang J, Ghirlando R, Norouzi D, Sathish Yadav KN, Feng H, Wang R, Zhang P, Zhurkin V, Bai Y. Revisit of Reconstituted 30-nm Nucleosome Arrays Reveals an Ensemble of Dynamic Structures. J Mol Biol. 2018;430(18 Pt B):3093-3110.
Fyodorov DV, Zhou BR, Skoultchi AI, Bai Y. Emerging roles of linker histones in regulating chromatin structure and function. Nat Rev Mol Cell Biol. 2018;19(3):192-206.
Chittori S, Hong J, Saunders H, Feng H, Ghirlando R, Kelly AE, Bai Y, Subramaniam S. Structural mechanisms of centromeric nucleosome recognition by the kinetochore protein CENP-N. Science. 2018;359(6373):339-343.
Kato H, Jiang J, Zhou BR, Rozendaal M, Feng H, Ghirlando R, Xiao TS, Straight AF, Bai Y. A conserved mechanism for centromeric nucleosome recognition by centromere protein CENP-C. Science. 2013;340(6136):1110-3.
Related Scientific Focus Areas
Biomedical Engineering and Biophysics
This page was last updated on November 26th, 2019