MOLECULAR ASPECTS OF THE ESCHERICHIA-COLI NUCLEOID PROTEIN, H-NS - A CENTRAL CONTROLLER OF GENE REGULATORY NETWORKS

The nucleoid-associated protein H-NS has a central role in the structu ring and control of the enteric bacterial chromosome. This protein has been demonstrated to contribute to the regulation of expression for a pproximately thirty genes. In this article, the molecular aspects of H -NS structure and function are briefly reviewed. H-NS contains at leas t two independent structural domains: a C-terminal domain, involved in the DNA-protein interactions, and a N-terminal domain, likely involve d in protein-protein interactions. Recent reports have revealed that H -NS is a key factor in a multi-component gene regulatory system. Facto rs have now been discovered which can backup or antagonise H-NS action at certain promoters. These recent findings are summarised and discus sed in relationship to the role of H-NS in DNA packaging and nucleoid structure.