The regulation of gene expression is governed by complex molecular interactions involving DNA, histones, and various regulatory proteins. These processes are driven by finely tuned thermodynamic forces and dynamic structural changes that span a wide range of time and length scales. A central structure in this regulation is the nucleosome, composed of DNA wrapped around histone proteins. While much is known about the static structures of nucleosomes, less is understood about how dynamic modifications affect their behavior and gene regulation. In this talk, I will present work from our group that uses molecular dynamics simulations to examine these effects at atomic resolution. We will explore how the flexible histone H3 tails are influenced by nucleosome composition and post-translational modifications, how the addition of large molecules like ubiquitin alters nucleosome stability and DNA compaction, and how viral nucleosome-like particles create destabilized chromatin structures. These studies demonstrate how small-scale molecular modifications can induce significant changes in the physical properties of nucleosomes, serving as a means of fine-tuning gene expression through the regulation of their dynamic behavior.
Jeff Wereszcynski, Professor, Illinois Institute of Technology
Host: John Marko