Molecular Evolution of the H-NS Protein: Interaction with Hha-Like Proteins Is Restricted toEnterobacteriaceae

Abstract
We show here that chromosomal hha-like genes are restricted to the Enterobacteriaceae. The H-NS N-terminal domain of members of this family includes an unaltered seven-amino-acid sequence located between helixes 1 and 2, termed the Hha signature, that contains key residues for H-NS-Hha interaction.