title: DNA packaging and ejection forces in bacteriophage.
abstract: We calculate the forces required to package (or, equivalently, acting to eject) DNA into (from) a bacteriophage capsid, as a function of the loaded (ejected) length, under conditions for which the DNA is either self-repelling or self-attracting. Through computer simulation and analytical theory, we find the loading force to increase more than 10-fold (to tens of piconewtons) during the final third of the loading process; correspondingly, the internal pressure drops 10-fold to a few atmospheres (matching the osmotic pressure in the cell) upon ejection of just a small fraction of the phage genome. We also determine an evolution of the arrangement of packaged DNA from toroidal to spool-like structures.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kindt
authors.forename: S
authors.initials: S
authors.lastname: Tzlil
authors.forename: A
authors.initials: A
authors.lastname: Ben-Shaul
authors.forename: W M
authors.initials: WM
authors.lastname: Gelbart
mesh_terms: D001435:Bacteriophages / Q000235:genetics*; D002213:Capsid / Q000502:physiology; D004279:DNA, Viral / Q000502:physiology*; D004735:Energy Transfer; D008432:Mathematical Computing; D019065:Virus Assembly / Q000502:physiology*
chemical_list: D004279:DNA, Viral