The effect of genome length on ejection forces in bacteriophage lambda.

TY - JOUR

T1 - The effect of genome length on ejection forces in bacteriophage lambda.

AU - Grayson, Paul

AU - Evilevitch, Alex

AU - Purohit, P. K.

AU - Gelbart, William M.

AU - Knobler, Charles M.

AU - Phillips, Robert

PY - 2006

Y1 - 2006

N2 - 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 λ, λb221cI26 and λcI60, 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, for the short and long genomes, respectively, values that are in agreement with our theoretical calculations.

AB - 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 λ, λb221cI26 and λcI60, 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, for the short and long genomes, respectively, values that are in agreement with our theoretical calculations.

KW - Bacteriophage

KW - Lambda

KW - LamB

KW - Maltoporin

KW - Genome delivery

KW - DNA ejection

KW - Pressure

U2 - 10.1016/j.virol.2006.01.003

DO - 10.1016/j.virol.2006.01.003

M3 - Article

C2 - 16469346

VL - 348

SP - 430

EP - 436

JO - Virology

JF - Virology

SN - 1096-0341

IS - 2

ER -