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Nucleosomes are elementary units of chromatin, comprising an octamer of histone proteins (consisting of two pairs of H3H4 and H2AH2B histone dimers) which wraps around 150 base pairs of DNA in a lefthanded superhelix. While compacting the DNA, nucleosomes remain actively involved in the processes of transcription, DNA replication, repair and provide basis for the epigenetic markup of the genome through the incorporation of histone variants and posttranslational modifications. It is known that nucleosomes are inherently dynamic structures that may unwrap DNA or loose certain histone dimers. However, recent findings suggest that the fine plasticity of the histone octamer itself as well as of the individual histone dimers is of key importance for the interaction of nucleosomes with chromatin proteins complexes such as nucleosome remodelers. For example, incorporation of disulfide bonds within the histone dimers alters the remodeling process. Motivated by these findings we aimed at deciphering the various internal motions within the nucleosome core using molecular dynamics (MD) simulations. We performed MD simulations of a complete nucleosome core particle, a histone H3H4 tetramer, and individual histone dimers as well as the said systems incorporating different mutations. The metadynamics simulations approach was used to explore the systems’ behavior along the select collective variables. Particularly the plasticity of the tetrasome structure was explored with respect to the deformation of the DNA, which resembles DNA stretching or supercoiling. Using principal component analysis we revealed a number of internal motion modes within the histone dimers, which include long alpha 2 helix bending. Overall our findings contribute to the understanding of the nucleosome as an internally dynamic entity with implications for functional interactions with other chromatin proteins. This work was supported by Russian Science Foundation Grant No.187410006.