3FK6

Crystal structure of TetR triple mutant (H64K, S135L, S138I)

Summary for 3FK6

• Entry DOI: 10.2210/pdb3fk6/pdb
• Related: 2O7O 2TCT 2VKE 2VKV 3FK7
• Descriptor: Tetracycline repressor protein class B from transposon Tn10, Tetracycline repressor protein class D (2 entities in total)
• Functional Keywords: tetracycline repressor, bacterial transcription regulation, altered inducer specificity, 4-de-dimethylamino-anhydrotetracycline, antibiotic resistance, dna-binding, magnesium, metal-binding, repressor, transcription, transcription regulation, transposable element
• Biological source: Escherichia coli; More
• Total number of polymer chains: 2
• Total formula weight: 46897.60

Authors

Klieber, M.A.,Scholz, O.,Lochner, S.,Gmeiner, P.,Hillen, W.,Muller, Y.A. (deposition date: 2008-12-16, release date: 2009-10-27, Last modification date: 2023-11-01)

Primary citation

Klieber, M.A.,Scholz, O.,Lochner, S.,Gmeiner, P.,Hillen, W.,Muller, Y.A.
Structural origins for selectivity and specificity in an engineered bacterial repressor-inducer pair.
Febs J., 276:5610-5621, 2009

PubMed Abstract: The bacterial tetracycline transcription regulation system mediated by the tetracycline repressor (TetR) is widely used to study gene expression in prokaryotes and eukaryotes. To study multiple genes in parallel, a triple mutant TetR(K(64)L(135)I(138)) has been engineered that is selectively induced by the synthetic tetracycline derivative 4-de-dimethylamino-anhydrotetracycline (4-ddma-atc) and no longer by tetracycline, the inducer of wild-type TetR. In the present study, we report the crystal structure of TetR(K(64)L(135)I(138)) in the absence and in complex with 4-ddma-atc at resolutions of 2.1 A. Analysis of the structures in light of the available binding data and previously reported TetR complexes allows for a dissection of the origins of selectivity and specificity. In all crystal structures solved to date, the ligand-binding position, as well as the positioning of the residues lining the binding site, is extremely well conserved, irrespective of the chemical nature of the ligand. Selective recognition of 4-ddma-atc is achieved through fine-tuned hydrogen-bonding constraints introduced by the His64-->Lys substitution, as well as a combination of hydrophobic effect and the removal of unfavorable electrostatic interactions through the introduction of Leu135 and Ile138.

PubMed: 19712110
DOI: 10.1111/j.1742-4658.2009.07254.x

Experimental method

X-RAY DIFFRACTION (2.1 Å)