Abstract

The three-dimensional organisation of the DNA is one of the great marvels of physical biology. By winding around a special class of proteins, the metre-long DNA manages to compress enormously to fit inside tiny (6 μm) nuclei, avoid entanglement and, moreover, maintain exquisite control over the accessibility of the information it carries. The structure of this remarkable complex of DNA and proteins, known as chromatin, determines how easily the DNA can be accessed and, thus, it is intimately linked to gene expression regulation. In this talk, I will present our multiscale modelling techniques designed to investigate the structure of chromatin in conditions that mimic those inside cells (Farr et al, Nature Communications, 2021). I will discuss why nucleosomes, the building blocks of chromatin, should be viewed as highly plastic particles that foster multivalent interactions and promote chromatin’s liquid-liquid phase separation.