Efficient repression by a heterodimeric repressor in Escherichia coli

Mol Microbiol. 1992 Feb;6(3):371-7. doi: 10.1111/j.1365-2958.1992.tb01480.x.


Previous studies with purified variants of the 434 repressor having different operator-binding specificities have demonstrated the interactions of a heterodimeric repressor with a hybrid operator site. The present study investigates the interactions between the 434 repressor and its operator site. The optimum 434 operator half-site is used with a P22 operator half-site to create a hybrid 434/P22 operator. We show that this hybrid operator can be efficiently bound by a heterodimeric repressor, consisting of one wild-type 434 repressor monomer and one 434 repressor monomer with the binding specificity of the P22 repressor, to bring about repression in Escherichia coli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • DNA, Bacterial / metabolism
  • Escherichia coli / genetics*
  • Molecular Sequence Data
  • Operator Regions, Genetic
  • Plasmids
  • Repressor Proteins / metabolism*
  • Viral Proteins


  • 434-repressor protein, Bacteriophage 434
  • DNA, Bacterial
  • Repressor Proteins
  • Viral Proteins