Role of DNA-DNA sliding friction and nonequilibrium dynamics in viral genome ejection and packaging.

ABSTRACT: Many viruses eject their DNA via a nanochannel in the viral shell, driven by internal forces arising from the high-density genome packing. The speed of DNA exit is controlled by friction forces that limit the molecular mobility, but the nature of this friction is unknown. We introduce a method to probe the mobility of the tightly confined DNA by measuring DNA exit from phage phi29 capsids with optical tweezers. We measure extremely low initial exit velocity, a regime of exponentially increasing velocity, stochastic pausing that dominates the kinetics and large dynamic heterogeneity. Measurements with variable applied force provide evidence that the initial velocity is controlled by DNA-DNA sliding friction, consistent with a Frenkel-Kontorova model for nanoscale friction. We confirm severa

SUBMITTER: Fizari M 

PROVIDER: S-EPMC10450192 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature