TetR Proteins and Enzymes

TetR, Tet repressor protein, is a 23kD protein that regulates transcription of a family of tetracycline resistance determinants in Gram-negative bacteria. The Tet system is the most widely used regulatory system for conditional gene expression in eukaryotic cells. TetR can be used for that purpose in some organisms without further modifications. In mammals and in a large variety of other organisms, however, eukaryotic transcriptional activator or repressor domains are fused to TetR to turn it into an efficient regulator.