TetR

rdf:langString TetR

rdf:langString Tet Repressor proteins (otherwise known as TetR) are proteins playing an important role in conferring antibiotic resistance to large categories of bacterial species. Tetracycline (Tc) is a broad family of antibiotics to which bacteria have evolved resistance. Tc normally kills bacteria by binding to the bacterial ribosome and halting protein synthesis. The expression of Tc resistance genes is regulated by the repressor TetR. TetR represses the expression of TetA, a membrane protein that pumps out substances toxic to the bacteria like Tc, by binding the tetA operator. In Tc-resistant bacteria, TetA will pump out Tc before it can bind to the ribosome because the repressive action of TetR on TetA is halted by binding of Tc to TetR. Therefore, TetR may have an important role in helping scientists to better understand mechanisms of antibiotic resistance and how to treat antibiotic resistant bacteria. TetR is one of many proteins in the TetR protein family, which is so named because TetR is the most well characterized member. TetR is used in artificially engineered gene regulatory networks because of its capacity for fine regulation of promoters. In the absence of Tc or analogs like ATc, basal expression of TetR-regulated promoters is low, but expression rises sharply in the presence of even a minute quantity of Tc. The tetA gene is also present in the widely used E. coli cloning vector pBR322, where it is often referred to by the name of its tetracycline-resistance phenotype, TetR, not to be confused with TetR.