Escherichia coli single-strand binding protein stabilizes specific denatured sites in superhelical DNA.

Escherichia coli single-strand binding protein relaxes supercoiled DNA molecules containing the Drosophila melanogaster histone gene repeat unit, by stabilizing denaturation bubbles that map near the boundaries of the genes, at sites that in native chromatin have been shown to be hypersensitive to nucleases. A similar process may contribute to the propagation of such hypersensitive sites after their induction on the activation of gene expression.