DNA compaction by nonbinding macromolecules

Compaction of DNA by nonbinding macromolecules such as uncharged flexible polymer chains and negatively charged globular proteins is thought to have various applications in biophysics, for example in the formation of a nucleoid structure in bacteria. A simple experimental model that has been very well studied is the classic DNA ¿-condensation induced by polymers and salt. In recent years, compaction of DNA by nonbinding macromolecules has been reconsidered under conditions that are closer to the biophysical applications, in various respect. This work is reviewed here. Topics that are considered are: DNA compaction by nonbinding globular proteins, the influence of DNA binding proteins and DNA topology on ¿-condensation, and finally, the impact of confinement on DNA ¿-condensatio