Molecular analysis of the Escherichia coli hns gene encoding a DNA-binding protein, which preferentially recognizes curved DNA sequences.

We previously demonstrated that the E. coli protein, H-NS (or H1a), encoded by the gene hns (or osmZ or bglY) preferentially recognizes curved DNA sequences in vitro. In order to gain further insight into the complex function of H-NS and the significance of DNA curvature, we constructed a structurally defined hns deletion mutant on the E. coli chromosome. The hns deletion mutant thus obtained showed a variety of phenotypes previously for other lesions in hns. It was further demonstrated that, in this hns deletion background, numerous E. coli cellular proteins were either strongly expressed or remarkably repressed, as compared to their expression levels in wild-type cells.