Seminario: Alex Evilevitch - Martes 30 de junio 10:30 hs

How DNA Bending Generates Pressure that makes Viruses Infectious

Double-stranded DNA viruses package micrometer-long genomes into nanometer-scale capsids, generating internal pressures that power genome release during infection. While DNA–DNA interactions have traditionally been considered the dominant source of this pressure, the contribution of DNA bending stress has remained difficult to quantify experimentally.
In this lecture, I will present how osmotic stress measurements and small-angle X-ray scattering can be combined to establish an equation of state for DNA confined inside viral capsids. These measurements reveal that DNA bending is not a minor correction to intermolecularinteractions, but a major contributor to viral genome pressure and can become dominant as genome density decreases. Capsid curvature, ionic conditions, and temperature emerge as key physical parameters controlling the mechanical state of confined genomes.
These findings provide a unified physical framework linking polymer elasticity, DNA organization, and pressure-driven infection, and illustrate how fundamental concepts in physical chemistry can uncover the mechanical principles underlying viral function.