  Dynamics of nucleosomes, the building blocks of the chromatin, has crucial
effects on expression, replication and repair of genomes in eukaryotes. Beside
constant movements of nucleosomes by thermal fluctuations, ATP-dependent
chromatin remodelling complexes cause their active displacements. Here we
propose a theoretical analysis of dinucleosome wrapping and unwrapping dynamics
in the presence of an external force. We explore the energy landscape and
configurations of dinucleosome in different unwrapped states. Moreover, using a
dynamical Monte-Carlo simulation algorithm, we demonstrate the dynamical
features of the system such as the unwrapping force for partial and full
wrapping processes. Furthermore, we show that in the short length of linker DNA
($\sim 10 - 90$ bp), the asymmetric unwrapping occurs. These findings could
shed some light on chromatin dynamics and gene accessibility.
