Protein Domain : Tetracycline repressor TetR, C-terminal IPR004111

Type	Domain
Description	This entry represents the C-terminal domain found in the tetracycline transcriptional repressor TetR, which binds to the Tet(A) gene to repress its expression in the absence of tetracycline [ ]. Tet(A) is a membrane-associated efflux protein that exports tetracycline from the cell before it can attach to ribosomes and inhibit polypeptide chain growth. TetR occurs as a homodimer and uses two helix-turn-helix (HTH) motifs to bind tandem DNA operators, thereby blocking the expression of the associated genes, TetA and TetR. The structure of the class D TetR repressor protein [] involves 10 α-helices, with connecting turns and loops. The three N-terminal helices constitute the DNA-binding HTH domain, which has an inverse orientation compared with HTH motifs in other DNA-binding proteins. The core of the protein, formed by helices 5-10, is responsible for dimerisation and contains, for each monomer, a binding pocket that accommodates tetracycline in the presence of a divalent cation.
Short Name	Repressor_TetR_C