2005/05/21 by Paul Grayson, Grayson, Paul, Alex Evilevitch +11
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Bacterial Genetics and Biotechnology #Bacteriophages and microbial interactions #Biomolecules (q-bio.BM) #FOS: Biological sciences #Protein Structure and Dynamics #q-bio.BM
paper · pdf · doi:10.48550/arxiv.q-bio/0505042
arxiv created 2005/05/21 · openalex publication_date 2005/05/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A variety of viruses tightly pack their genetic material into protein capsids that are barely large enough to enclose the genome. In particular, in bacteriophages, forces as high as 60 pN are encountered during packaging and ejection, produced by DNA bending elasticity and self-interactions. The high forces are believed to be important for the ejection process, though the extent of their involvement is not yet clear. As a result, there is a need for quantitative models and experiments that reveal the nature of the forces relevant to DNA ejection. Here we report measurements of the ejection forces for two different mutants of bacteriophage lambda, lambda b221cI26 and lambda cI60, which differ in genome length by ~30%. As expected for a force-driven ejection mechanism, the osmotic pressure at which DNA release is completely inhibited varies with the genome length: we find inhibition pressures of 15 atm and 25 atm, respectively, values that are in agreement with our theoretical calculations.