Tetracycline repressor TetR(D), unliganded

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.215 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Tetracycline Repressor Allostery Does not Depend on Divalent Metal Recognition.

Werten, S.Dalm, D.Palm, G.J.Grimm, C.C.Hinrichs, W.

(2014) Biochemistry 53: 7990

  • DOI: https://doi.org/10.1021/bi5012805
  • Primary Citation of Related Structures:  
    2XPU, 4D7M, 4D7N, 4V2F, 4V2G

  • PubMed Abstract: 

    Genes that render bacteria resistant to tetracycline-derived antibiotics are tightly regulated by repressors of the TetR family. In their physiologically relevant, magnesium-complexed form, tetracyclines induce allosteric rearrangements in the TetR homodimer, leading to its release from the promoter and derepression of transcription. According to earlier crystallographic work, recognition of the tetracycline-associated magnesium ion by TetR is crucial and triggers the allosteric cascade. Nevertheless, the derivative 5a,6-anhydrotetracycline, which shows an increased affinity for TetR, causes promoter release even in the absence of magnesium. To resolve this paradox, it has been proposed that metal-free 5a,6-anhydrotetracycline acts via an exceptional, conformationally different induction mode that circumvents the normal magnesium requirement. We have tested this hypothesis by determining crystal structures of TetR-5a,6-anhydrotetracycline complexes in the presence of magnesium, ethylenediaminetetraacetic acid, or high concentrations of potassium. Analysis of these three structures reveals that, irrespective of the metal, the effects of 5a,6-anhydrotetracycline binding are indistinguishable from those of canonical induction by other tetracyclines. Together with a close scrutiny of the earlier evidence of a metal-triggered mechanism, these results demonstrate that magnesium recognition per se is not a prerequisite for tetracycline repressor allostery.

  • Organizational Affiliation

    Department of Molecular Structural Biology, Institute for Biochemistry, University of Greifswald , Felix-Hausdorff-Strasse 4, D-17487 Greifswald, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TETRACYCLINE REPRESSOR PROTEIN CLASS D207Escherichia coliMutation(s): 0 
Find proteins for P0ACT4 (Escherichia coli)
Explore P0ACT4 
Go to UniProtKB:  P0ACT4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0ACT4
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.215 
  • Space Group: I 41 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.79α = 90
b = 69.79β = 90
c = 182.34γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-12-10
    Type: Initial release
  • Version 1.1: 2015-01-14
    Changes: Database references
  • Version 1.2: 2019-07-17
    Changes: Data collection
  • Version 1.3: 2024-01-10
    Changes: Data collection, Database references, Other, Refinement description