2TRT

TETRACYCLINE REPRESSOR CLASS D

• PDB DOI: https://doi.org/10.2210/pdb2TRT/pdb
• Entry: 2TRT supersedes: 1TRT

• Classification: TRANSCRIPTION REGULATION
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1994-03-04 Released: 1996-06-20 
• Deposition Author(s): Hinrichs, W., Kisker, C., Saenger, W.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Work: 0.190 
• R-Value Observed: 0.190 

Literature

Structure of the Tet repressor-tetracycline complex and regulation of antibiotic resistance.

Hinrichs, W., Kisker, C., Duvel, M., Muller, A., Tovar, K., Hillen, W., Saenger, W.

(1994) Science 264: 418-420

• PubMed: 8153629 
• DOI: https://doi.org/10.1126/science.8153629
• Primary Citation of Related Structures:  
  2TRT, 2XB5


• PubMed Abstract: 
  

  The most frequently occurring resistance of Gram-negative bacteria against tetracyclines is triggered by drug recognition of the Tet repressor. This causes dissociation of the repressor-operator DNA complex and enables expression of the resistance protein TetA, which is responsible for active efflux of tetracycline. The 2.5 angstrom resolution crystal structure of the homodimeric Tet repressor complexed with tetracycline-magnesium reveals detailed drug recognition. The orientation of the operator-binding helix-turn-helix motifs of the repressor is inverted in comparison with other DNA binding proteins. The repressor-drug complex is unable to interact with DNA because the separation of the DNA binding motifs is 5 angstroms wider than usually observed.

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Organizational Affiliation: 

Institut für Kristallographie, Freie Universität Berlin, Germany.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 24.79 kDa 
• Atom Count: 1,690 
• Modelled Residue Count: 198 
• Deposited Residue Count: 217 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TETRACYCLINE REPRESSOR CLASS D	A	217	Escherichia coli	Mutation(s): 0
UniProt
Find proteins for P0ACT4 (Escherichia coli) Explore P0ACT4  Go to UniProtKB:  P0ACT4

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
TAC	C [auth A]	TETRACYCLINE C22 H24 N2 O8 OFVLGDICTFRJMM-WESIUVDSSA-N
MG	B [auth A]	MAGNESIUM ION Mg JLVVSXFLKOJNIY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Work: 0.190 
• R-Value Observed: 0.190 
• Space Group: I 4₁ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 68.32	α = 90
b = 68.32	β = 90
c = 181.14	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	refinement

Structure Validation

Entry History 

Deposition Data

• Released Date: 1996-06-20 
Deposition Author(s): Hinrichs, W., Kisker, C., Saenger, W.
• This entry supersedes: 1TRT

Revision History  

• Version 1.0: 1996-06-20
  Type: Initial release
  
• Version 1.1: 2008-03-25
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2017-11-29
  Changes: Derived calculations, Other
• Version 1.4: 2024-02-21
  Changes: Data collection, Database references, Derived calculations