3BR3

Crystal Structure of the Complex of Ethidium Bound to QacR(E90Q), a Mutant of a Multidrug Binding Transcriptional Repressor

• PDB DOI: https://doi.org/10.2210/pdb3BR3/pdb

• Classification: TRANSCRIPTION
• Organism(s): Staphylococcus aureus
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2007-12-20 Released: 2008-12-23 
• Deposition Author(s): Brooks, B.E.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.293 
• R-Value Work: 0.218 
• R-Value Observed: 0.222 

Literature

Formal electrostatic interactions do not govern QacR-cation affinity

Brooks, B.E., Hardie, K.M., Brown, M.H., Skurray, R.A., Brennan, R.G.

To be published.

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Biological Assembly 2  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 2 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 46.96 kDa 
• Atom Count: 3,040 
• Modelled Residue Count: 368 
• Deposited Residue Count: 388 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
HTH-type transcriptional regulator qacR	A [auth B], B [auth A]	194	Staphylococcus aureus	Mutation(s): 4  Gene Names: qacR
UniProt
Find proteins for P0A0N3 (Staphylococcus aureus (strain Mu50 / ATCC 700699)) Explore P0A0N3  Go to UniProtKB:  P0A0N3

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ET	H [auth A]	ETHIDIUM C21 H20 N3 QTANTQQOYSUMLC-UHFFFAOYSA-O
SO4	C [auth B], D [auth B], E [auth B], F [auth B], G [auth B], I [auth A], J [auth A], K [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.293 
• R-Value Work: 0.218 
• R-Value Observed: 0.222 
• Space Group: P 6₂

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 104.148	α = 90
b = 104.148	β = 90
c = 98.564	γ = 120

Software Package:

Software Name	Purpose
REFMAC	refinement
CrystalClear	data collection
d*TREK	data reduction
d*TREK	data scaling
MOLREP	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2008-12-23 
Deposition Author(s): Brooks, B.E.

Revision History  

• Version 1.0: 2008-12-23
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Advisory, Version format compliance
• Version 1.2: 2021-10-20
  Changes: Database references, Derived calculations
• Version 1.3: 2023-08-30
  Changes: Data collection, Refinement description