Histone-based self-assembly into DNA-wrapped meso-clusters.

The recent discovery of meso-cluster phase includes not only colloidal molecules of synthetic polymer particles but also equilibrium protein clusters. Here we report self-assembly of histone protein into stable submicron clusters that can be generated even in centrifuged supernatants containing no initial aggregates. Furthermore, dark-field microscopy of the electrophoresis has verified charge reversal of individual histone clusters by adding DNA. We have determined the critical nucleotide concentration at which the electrophoretic mobility vanishes in three types of DNA, revealing the coexistence of nucleosomes with DNA-wrapped meso-clusters.