DNA packaging and ejection forces in bacteriophage.
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.
Kindt
J
J
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.
Tzlil
S
S
Ben-Shaul
A
A
Gelbart
W M
WM
D001435:Bacteriophages / Q000235:genetics*; D002213:Capsid / Q000502:physiology; D004279:DNA, Viral / Q000502:physiology*; D004735:Energy Transfer; D008432:Mathematical Computing; D019065:Virus Assembly / Q000502:physiology*
D004279:DNA, Viral