Phenotypes of combined tet repressor mutants for effector and operator recognition and allostery

J Mol Microbiol Biotechnol. 2004;8(2):104-10. doi: 10.1159/000084565.


Tet repressor mutants with a shifted effector specificity, preference for a mutant operator sequence or reversion of activity were combined to construct variants bearing two or three phenotypic alterations. TetR alleles with combinations of altered operator and effector specificities can be created by merging the respective residues in a single polypeptide. The mutations giving rise to revTetR, on the other hand, show drastic influences on the ligand binding phenotypes when combined with respective alterations. One TetR variant displays all three phenotypic alterations and thus demonstrates the general possibility of implementing them in one protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allosteric Regulation
  • Escherichia coli / chemistry
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Helix-Turn-Helix Motifs / genetics*
  • Operator Regions, Genetic / genetics
  • Operator Regions, Genetic / physiology*
  • Phenotype
  • Recombination, Genetic
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology*


  • Repressor Proteins
  • tetracycline resistance-encoding transposon repressor protein