Autoregulatory expression of the Escherichia coli hns gene encoding a nucleoid protein: H-NS functions as a repressor of its own transcription

Mol Gen Genet. 1993 Jan;236(2-3):171-8. doi: 10.1007/BF00277109.


The Escherichia coli nucleoid protein, H-NS (or H1a), appears to influence the regulation of a variety of unrelated E. coli genes and operons. To gain an insight into the regulation of the hns gene itself, we constructed in this study a hns-lacZ transcriptional fusion gene and inserted a single copy at the att lambda locus on the E. coli chromosome. Expression of hns transcription appeared to be moderately regulated in a growth phase-dependent manner. It also emerged that hns transcription is under negative autoregulation, at least in the logarithmic growth phase. The results of in vitro transcription experiments confirmed that H-NS functions as a repressor for its own transcription. Thus, H-NS was shown to exhibit relatively high affinity for the DNA sequence encompassing the hns promoter region, as compared with a non-specific sequence. These results support the view that the nucleoid protein, H-NS, can function as a transcriptional regulator.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / genetics*
  • Bacterial Proteins*
  • Cell Division
  • Cell-Free System
  • DNA, Bacterial / metabolism
  • DNA, Recombinant / genetics
  • DNA-Binding Proteins / genetics*
  • Escherichia coli / genetics*
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial / genetics*
  • Homeostasis
  • Lac Operon / genetics
  • Nuclear Proteins
  • Promoter Regions, Genetic / genetics
  • Repressor Proteins / genetics
  • Transcription, Genetic*


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • DNA, Bacterial
  • DNA, Recombinant
  • DNA-Binding Proteins
  • H-NS protein, bacteria
  • Nuclear Proteins
  • Repressor Proteins