Analysing Small DNA Constructs via a Chromophore Model within the Point Dipole Approximation

Abstract

their dysregulation in disease. However, the molecular mechanisms that drive these phase transitions, the biophysical properties of the resulting droplets, and the way their properties impact biological function, remain poorly understood. Here, we focus on LAF-1, an essential DEAD-box RNA helicase associated with P granules in the C. elegans germline. We find that purified LAF-1 can phase separate into liquid droplets at near physiological (low mM) concentrations. LAF-1 droplet formation is driven by its disordered N-terminal RGG domain, which is both necessary and sufficient for droplet formation. We combine microrheology, FRAP, and single molecule imaging approaches to reveal the local viscoelastic properties and molecular dynamics inside the droplets. Our results provide mechanistic and structural insight into the phase transition-driven assembly of liquid-like organelles, and suggest that the biophysics of intracellular phase separation can sensitively control molecular dynamics and function.