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bioRxiv · 10.1101/2020.11.25.398180

Binding Dynamics of Disordered Linker Histone H1 with a Nucleosomal Particle

Wu, H.·Dalal, Y.·Papoian, G. A.
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Abstract

Linker histone H1 is an essential regulatory protein for many critical biological processes, such as eukaryotic chromatin packaging and gene expression. Mis-regulation of H1s is commonly observed in tumor cells, where the balance between different H1 subtypes has been shown to alter the cancer phenotype. Consisting of a rigid globular domain and two highly charged terminal domains, H1 can bind to multiple sites on a nucleosomal particle to alter chromatin hierarchical condensation levels. In particular, the disordered H1 amino- and carboxyl-terminal domains (NTD/CTD) are believed to enhance this binding affinity, but their detailed dynamics and functions remain unclear. In this work, we used a coarse-grained computational model AWSEM-DNA to simulate the H1.0b-nucleosome complex, namely chromatosome. Our results demonstrate that H1 disordered domains restrict the dynamics of both globular H1 and linker DNA arms, resulting in a more compact and rigid chromatosome particle. Furthermore, we identified regions of H1 disordered domains that are tightly tethered to DNA near the entry-exit site. Overall, our study elucidates at near atomic resolution the way the disordered linker histone H1 modulates nucleosomes structural preferences and conformational dynamics.

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Wu, H., Dalal, Y., Papoian, G. A.. 2020-11-26. Binding Dynamics of Disordered Linker Histone H1 with a Nucleosomal Particle. https://doi.org/10.1101/2020.11.25.398180

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