Effects of salt concentrations and bending energy on the extent of ejection of phage genomes

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Effects of salt concentrations and bending energy on the extent of ejection of phage genomes. / Evilevitch, Alex; Fang, Li Tai; Yoffe, Aron; Castelnovo, Martin; Rau, Donald C.; Parsegian, V. Adrian; Gelbart, William M.; Knobler, Charles M.

I: Biophysical Journal, Vol. 94, Nr. 3, 2008, s. 1110-1120.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

Evilevitch, A, Fang, LT, Yoffe, A, Castelnovo, M, Rau, DC, Parsegian, VA, Gelbart, WM & Knobler, CM 2008, 'Effects of salt concentrations and bending energy on the extent of ejection of phage genomes', Biophysical Journal, vol. 94, nr. 3, s. 1110-1120. https://doi.org/10.1529/biophysj.107.115345

APA

Evilevitch, A., Fang, L. T., Yoffe, A., Castelnovo, M., Rau, D. C., Parsegian, V. A., ... Knobler, C. M. (2008). Effects of salt concentrations and bending energy on the extent of ejection of phage genomes. Biophysical Journal, 94(3), 1110-1120. https://doi.org/10.1529/biophysj.107.115345

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MLA

Vancouver

Author

Evilevitch, Alex ; Fang, Li Tai ; Yoffe, Aron ; Castelnovo, Martin ; Rau, Donald C. ; Parsegian, V. Adrian ; Gelbart, William M. ; Knobler, Charles M. / Effects of salt concentrations and bending energy on the extent of ejection of phage genomes. I: Biophysical Journal. 2008 ; Vol. 94, Nr. 3. s. 1110-1120.

RIS

TY - JOUR

T1 - Effects of salt concentrations and bending energy on the extent of ejection of phage genomes

AU - Evilevitch, Alex

AU - Fang, Li Tai

AU - Yoffe, Aron

AU - Castelnovo, Martin

AU - Rau, Donald C.

AU - Parsegian, V. Adrian

AU - Gelbart, William M.

AU - Knobler, Charles M.

PY - 2008

Y1 - 2008

N2 - Recent work has shown that pressures inside dsDNA phage capsids can be as high as many tens of atmospheres; it is this pressure that is responsible for initiation of the delivery of phage genomes to host cells. The forces driving ejection of the genome have been shown to decrease monotonically as ejection proceeds, and hence to be strongly dependent on the genome length. Here we investigate the effects of ambient salts on the pressures inside phage-l, for the cases of mono-, di-, and tetravalent cations, and measure how the extent of ejection against a fixed osmotic pressure (mimicking the bacterial cytoplasm) varies with cation concentration. We find, for example, that the ejection fraction is halved in 30 mM Mg21 and is decreased by a factor of 10 upon addition of 1 mM spermine. These effects are calculated from a simple model of genome packaging, using DNA-DNA repulsion energies as determined independently from x-ray diffraction measurements on bulk DNA solutions. By comparing the measured ejection fractions with values implied from the bulk DNA solution data, we predict that the bending energy makes the d- spacings inside the capsid larger than those for bulk DNA at the same osmotic pressure.

AB - Recent work has shown that pressures inside dsDNA phage capsids can be as high as many tens of atmospheres; it is this pressure that is responsible for initiation of the delivery of phage genomes to host cells. The forces driving ejection of the genome have been shown to decrease monotonically as ejection proceeds, and hence to be strongly dependent on the genome length. Here we investigate the effects of ambient salts on the pressures inside phage-l, for the cases of mono-, di-, and tetravalent cations, and measure how the extent of ejection against a fixed osmotic pressure (mimicking the bacterial cytoplasm) varies with cation concentration. We find, for example, that the ejection fraction is halved in 30 mM Mg21 and is decreased by a factor of 10 upon addition of 1 mM spermine. These effects are calculated from a simple model of genome packaging, using DNA-DNA repulsion energies as determined independently from x-ray diffraction measurements on bulk DNA solutions. By comparing the measured ejection fractions with values implied from the bulk DNA solution data, we predict that the bending energy makes the d- spacings inside the capsid larger than those for bulk DNA at the same osmotic pressure.

U2 - 10.1529/biophysj.107.115345

DO - 10.1529/biophysj.107.115345

M3 - Article

VL - 94

SP - 1110

EP - 1120

JO - Biophysical Journal

JF - Biophysical Journal

SN - 1542-0086

IS - 3

ER -