1Q05

Crystal structure of the Cu(I) form of E. coli CueR, a copper efflux regulator

• PDB DOI: https://doi.org/10.2210/pdb1Q05/pdb

• Classification: TRANSCRIPTION
• Organism(s): Escherichia coli
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2003-07-15 Released: 2003-09-16 
• Deposition Author(s): Changela, A., Chen, K., Xue, Y., Holschen, J., Outten, C.E., O'Halloran, T.V., Mondragon, A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.253 
• R-Value Work: 0.208 
• R-Value Observed: 0.208 

Literature

Molecular basis of metal-ion selectivity and zeptomolar sensitivity by CueR

Changela, A., Chen, K., Xue, Y., Holschen, J., Outten, C.E., O'Halloran, T.V., Mondragon, A.

(2003) Science 301: 1383-1387

• PubMed: 12958362 
• DOI: https://doi.org/10.1126/science.1085950
• Primary Citation of Related Structures:  
  1Q05, 1Q06, 1Q07, 1Q08, 1Q09, 1Q0A


• PubMed Abstract: 
  

  The earliest of a series of copper efflux genes in Escherichia coli are controlled by CueR, a member of the MerR family of transcriptional activators. Thermodynamic calibration of CueR reveals a zeptomolar (10(-21) molar) sensitivity to free Cu+, which is far less than one atom per cell. Atomic details of this extraordinary sensitivity and selectivity for +1transition-metal ions are revealed by comparing the crystal structures of CueR and a Zn2+-sensing homolog, ZntR. An unusual buried metal-receptor site in CueR restricts the metal to a linear, two-coordinate geometry and uses helix-dipole and hydrogen-bonding interactions to enhance metal binding. This binding mode is rare among metalloproteins but well suited for an ultrasensitive genetic switch.

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Organizational Affiliation: 

Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, 2205Tech Drive, Evanston, IL 60208, USA.

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 (software)

Macromolecule Content

• Total Structure Weight: 30.64 kDa 
• Atom Count: 2,121 
• Modelled Residue Count: 249 
• Deposited Residue Count: 270 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Transcriptional regulator cueR	A, B	135	Escherichia coli	Mutation(s): 0  Gene Names: CUER
UniProt
Find proteins for P0A9G4 (Escherichia coli (strain K12)) Explore P0A9G4  Go to UniProtKB:  P0A9G4

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
CU1	C [auth A], D [auth B]	COPPER (I) ION Cu VMQMZMRVKUZKQL-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.253 
• R-Value Work: 0.208 
• R-Value Observed: 0.208 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 59.16	α = 90
b = 66.26	β = 90
c = 81.29	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
XDS	data reduction
CCP4	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2003-09-16 
Deposition Author(s): Changela, A., Chen, K., Xue, Y., Holschen, J., Outten, C.E., O'Halloran, T.V., Mondragon, A.

Revision History  

• Version 1.0: 2003-09-16
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2024-02-14
  Changes: Data collection, Database references, Derived calculations
• Version 1.4: 2024-04-03
  Changes: Refinement description