Histone Tail Dynamics in Partially Disassembled Nucleosomes During Chromatin Remodeling

Frontiers in Molecular Biosciences

Takeru Kameda¹  Yuichi Togashi³  Akinori Awazu⁴ 

[1] Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan;Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Japan;RIKEN Center for Biosystems Dynamics Research (BDR), Higashi-Hiroshima, Japan;Research Center for the Mathematics on Chromatin Live Dynamics (RcMcD), Hiroshima University, Higashi-Hiroshima, Japan;

关键词: nucleosome;    DNA;    histone;    chromatin;    structural dynamics;    hexasome;   

DOI  :  10.3389/fmolb.2019.00133

来源: DOAJ

【 摘 要 】

Nucleosomes are structural units of the chromosome consisting of DNA wrapped around histone proteins, and play important roles in compaction and regulation of the chromatin structure. While the structure and dynamics of canonical nucleosomes have been studied extensively, those of nucleosomes in intermediate states, that occur when their structure or positioning is modulated, have been less understood. In particular, the dynamic features of partially disassembled nucleosomes have not been discussed in previous studies. Using all-atom molecular dynamics simulations, in this study, we investigated the dynamics and stability of nucleosome structures lacking a histone-dimer. DNA in nucleosomes lacking a histone H2A/H2B dimer was drastically deformed due to loss of local interactions between DNA and histones. In contrast, conformation of DNA in nucleosomes lacking H3/H4 was similar to the canonical nucleosome, as the H2A C-terminal domain infiltrated the space originally occupied by the dissociated H3/H4 histones and restricted DNA dynamics in close proximity. Our results suggest that, besides histone chaperones, the intrinsic dynamics of nucleosomes support the exchange of H2A/H2B, which is significantly more frequent than that of H3/H4.

【 授权许可】

Unknown