3) As a bacteriophage is filled with DNA by the molecular motor within the connector,one would expect sliding friction to force the DNA to grind to a halt.This doesn’t happen owing to the peculiar properties of water.

4) A density gradient theory leads to a very simple algebraic equation.This doesn’t possess solutions below a certain minimum radius of curvature proving that holes free from DNA must exist.

Delft University of Technology, The Netherlands

1) The energies involved in compaction are not extensive so the usual thermodynamics does not hold.The elastic stress is greatly nonuniform within the DNA globule.

2) The usual polyelectrolyte cell model is useless because the DNA is close-packed.

3) As a bacteriophage is filled with DNA by the molecular motor within the connector,one would expect sliding friction to force the DNA to grind to a halt.This doesn’t happen owing to the peculiar properties of water.

4) A density gradient theory leads to a very simple algebraic equation.This doesn’t possess solutions below a certain minimum radius of curvature proving that holes free from DNA must exist.

Delft University of Technology, The Netherlands

How DNA is compacted in a bacteriophage or virus is an important problem at the physics-biology interface.The packaging of linear DNA inside a phage may seem like an almost trivial problem in polymer physics boiling down to the statistical mechanics of a chain confined within a cavity.Nevertheless, the physics of compaction turns out to be rather surprising because, ultimately, the size of a phage is merely of the order of the DNA persistence length so that high bending stresses come into play leading to the following conclusions:

1) The energies involved in compaction are not extensive so the usual thermodynamics does not hold.The elastic stress is greatly nonuniform within the DNA globule.

2) The usual polyelectrolyte cell model is useless because the DNA is close-packed.

3) As a bacteriophage is filled with DNA by the molecular motor within the connector,one would expect sliding friction to force the DNA to grind to a halt.This doesn’t happen owing to the peculiar properties of water.

4) A density gradient theory leads to a very simple algebraic equation.This doesn’t possess solutions below a certain minimum radius of curvature proving that holes free from DNA must exist.

Delft University of Technology, The Netherlands

How DNA is compacted in a bacteriophage or virus is an important problem at the physics-biology interface.The packaging of linear DNA inside a phage may seem like an almost trivial problem in polymer physics boiling down to the statistical mechanics of a chain confined within a cavity.Nevertheless, the physics of compaction turns out to be rather surprising because, ultimately, the size of a phage is merely of the order of the DNA persistence length so that high bending stresses come into play leading to the following conclusions:

1) The energies involved in compaction are not extensive so the usual thermodynamics does not hold.The elastic stress is greatly nonuniform within the DNA globule.

2) The usual polyelectrolyte cell model is useless because the DNA is close-packed.

3) As a bacteriophage is filled with DNA by the molecular motor within the connector,one would expect sliding friction to force the DNA to grind to a halt.This doesn’t happen owing to the peculiar properties of water.

4) A density gradient theory leads to a very simple algebraic equation.This doesn’t possess solutions below a certain minimum radius of curvature proving that holes free from DNA must exist.

Delft University of Technology, The Netherlands

How DNA is compacted in a bacteriophage or virus is an important problem at the physics-biology interface.The packaging of linear DNA inside a phage may seem like an almost trivial problem in polymer physics boiling down to the statistical mechanics of a chain confined within a cavity.Nevertheless, the physics of compaction turns out to be rather surprising because, ultimately, the size of a phage is merely of the order of the DNA persistence length so that high bending stresses come into play leading to the following conclusions:

1) The energies involved in compaction are not extensive so the usual thermodynamics does not hold.The elastic stress is greatly nonuniform within the DNA globule.

2) The usual polyelectrolyte cell model is useless because the DNA is close-packed.

3) As a bacteriophage is filled with DNA by the molecular motor within the connector,one would expect sliding friction to force the DNA to grind to a halt.This doesn’t happen owing to the peculiar properties of water.

4) A density gradient theory leads to a very simple algebraic equation.This doesn’t possess solutions below a certain minimum radius of curvature proving that holes free from DNA must exist.

Delft University of Technology, The Netherlands