The H-NS protein modulates the activation of the ilvIH operon of Escherichia coli K12 by Lrp, the leucine regulatory protein.
The H-NS protein, the product of the hns gene, plays a central role in the cellular response of bacteria to environmental stresses such as modification of osmolarity and temperature. The leucine regulatory protein (Lrp) controls a wide array of operons both as an activator (e.g. ilvIH) and as a repressor. We demonstrate that H-NS can decrease the activity of Lrp in stationary phase and under conditions of high osmolarity. Strains containing hns mutations have higher levels of Lrp-activated ilvIH transcription, while strains carrying the hns+ allele on a pBR322 plasmid have lower activity of Lrp-directed ilvIH gene expression.
Levinthal
M
M
Department of Biological Sciences, Purdue University, W. Lafayette, IN 47907.
Lejeune
P
P
Danchin
A
A
D000483:Alleles; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D051756:Leucine-Responsive Regulatory Protein; D005810:Multigene Family; D009154:Mutation; D009876:Operon; D018085:Regulon; D014157:Transcription Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014882:Water-Electrolyte Balance / Q000235:genetics
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C031908:H-NS protein, bacteria; C497278:Lrp protein, E coli; D014157:Transcription Factors; D051756:Leucine-Responsive Regulatory Protein