2QCP

1.0 A Structure of CusF-Ag(I) residues 10-88 from Escherichia coli

• PDB DOI: https://doi.org/10.2210/pdb2QCP/pdb

• Classification: METAL BINDING PROTEIN
• Organism(s): Escherichia coli str. K-12 substr. W3110
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2007-06-19 Released: 2007-10-02 
• Deposition Author(s): Loftin, I.R.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.00 Å
• R-Value Free: 0.186 
• R-Value Work: 0.159 
• R-Value Observed: 0.160 

Literature

Unusual Cu(I)/Ag(I) coordination of Escherichia coli CusF as revealed by atomic resolution crystallography and X-ray absorption spectroscopy

Loftin, I.R., Franke, S., Blackburn, N.J., McEvoy, M.M.

(2007) Protein Sci 16: 2287-2293

• PubMed: 17893365 
• DOI: https://doi.org/10.1110/ps.073021307
• Primary Citation of Related Structures:  
  2QCP


• PubMed Abstract: 
  

  Elevated levels of copper or silver ions in the environment are an immediate threat to many organisms. Escherichia coli is able to resist the toxic effects of these ions through strictly limiting intracellular levels of Cu(I) and Ag(I). The CusCFBA system is one system in E. coli responsible for copper/silver tolerance. A key component of this system is the periplasmic copper/silver-binding protein, CusF. Here the X-ray structure and XAS data on the CusF-Ag(I) and CusF-Cu(I) complexes, respectively, are reported. In the CusF-Ag(I) structure, Ag(I) is coordinated by two methionines and a histidine, with a nearby tryptophan capping the metal site. EXAFS measurements on the CusF-Cu(I) complex show a similar environment for Cu(I). The arrangement of ligands effectively sequesters the metal from its periplasmic environment and thus may play a role in protecting the cell from the toxic ion.

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Organizational Affiliation: 

Department of Biochemistry and Molecular Biophysics, University of Arizona, Tucson, Arizona 85721, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

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

Macromolecule Content

• Total Structure Weight: 9.32 kDa 
• Atom Count: 848 
• Modelled Residue Count: 80 
• Deposited Residue Count: 80 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cation efflux system protein cusF	A [auth X]	80	Escherichia coli str. K-12 substr. W3110	Mutation(s): 0  Gene Names: cusF, cusX
UniProt
Find proteins for P77214 (Escherichia coli (strain K12)) Explore P77214  Go to UniProtKB:  P77214

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
AG	F [auth X]	SILVER ION Ag FOIXSVOLVBLSDH-UHFFFAOYSA-N
SO4	C [auth X], E [auth X]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
NO3	B [auth X], D [auth X]	NITRATE ION N O3 NHNBFGGVMKEFGY-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.00 Å
• R-Value Free: 0.186 
• R-Value Work: 0.159 
• R-Value Observed: 0.160 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 38.118	α = 90
b = 39.351	β = 90
c = 44.423	γ = 90

Software Package:

Software Name	Purpose
SCALA	data scaling
MOLREP	phasing
REFMAC	refinement
PDB_EXTRACT	data extraction
Blu-Ice	data collection
CrystalClear	data reduction

Structure Validation

Entry History 

Deposition Data

• Released Date: 2007-10-02 
Deposition Author(s): Loftin, I.R.

Revision History  

• Version 1.0: 2007-10-02
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Source and taxonomy, Version format compliance
• Version 1.2: 2023-08-30
  Changes: Data collection, Database references, Refinement description