Alterations of the outer membrane composition in Escherichia coli lacking the histone-like protein HU

Proc Natl Acad Sci U S A. 1997 Jun 24;94(13):6712-7. doi: 10.1073/pnas.94.13.6712.


Escherichia coli cells lacking the histone-like protein HU form filaments and have an abnormal number of anucleate cells. Furthermore, their phenotype resembles that of rfa mutants, the well-characterized deep-rough phenotype, as they show an enhanced permeability that renders them hypersensitive to chloramphenicol, novobiocin, and detergents. We show that, unlike rfa mutants, hupAB mutants do not have a truncated lipopolysaccharide but do have an abnormal abundance of OmpF porin in their outer membrane. While the complete absence of HU does not abolish the osmoregulation of OmpF protein synthesis, the steady-state level of micF RNA, the negative regulator of OmpF, decreases in bacteria lacking HU, increasing the basal level of this membrane protein. These findings demonstrate a novel link between a bacterial chromosomal protein and the outer membrane composition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Bacterial Proteins / genetics*
  • DNA-Binding Proteins / genetics*
  • Escherichia coli / chemistry
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Gene Deletion
  • Gene Expression Regulation, Bacterial
  • Lipopolysaccharides / chemistry
  • Lipopolysaccharides / metabolism
  • Osmolar Concentration
  • Water-Electrolyte Balance / genetics


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • DNA-Binding Proteins
  • Lipopolysaccharides
  • histone-like protein HU, bacteria