Computational Study on Flexible Dynamics of Histone Tails

Abstract

Post-translational modifications of histone tails regulate DNA transcription in eukaryotic cells. The flexibility of the histone tails is considered to be crucial for the transcription regulation, but details of their molecular mechanism remain unclear. In the present study, we characterized conformational dynamics of flexible histone tails using molecular dynamics (MD) simulations. We selected histone tails of H2A/H2B dimer as targets, and performed one microsecond MD simulations in explicit water using MARBLE and the CHARMM22/CMAP force field parameters. In order to elucidate flexible dynamics of the histone tails, we focused on their slow dynamics, such as slowly changing motions and rare events, and identified them by applying the time-structure based independent component analysis (tICA) to the obtained MD trajectories. By further analysis of the simulation results, it was confirmed that the detected slow dynamics was actually occurred. We will discuss underlying mechanism and functional significance of the slow dynamics.