Crystal Structure of Pseudomonas aeruginosa azurin with iron(II) at the copper-binding site.

Experimental Data Snapshot

  • Resolution: 2.20 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.245 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Azurin as a Protein Scaffold for a Low-coordinate Nonheme Iron Site with a Small-molecule Binding Pocket.

McLaughlin, M.P.Retegan, M.Bill, E.Payne, T.M.Shafaat, H.S.Pena, S.Sudhamsu, J.Ensign, A.A.Crane, B.R.Neese, F.Holland, P.L.

(2012) J Am Chem Soc 134: 19746-19757

  • DOI: https://doi.org/10.1021/ja308346b
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The apoprotein of Pseudomonas aeruginosa azurin binds iron(II) to give a 1:1 complex, which has been characterized by electronic absorption, Mössbauer, and NMR spectroscopies, as well as X-ray crystallography and quantum-chemical computations. Despite potential competition by water and other coordinating residues, iron(II) binds tightly to the low-coordinate site. The iron(II) complex does not react with chemical redox agents to undergo oxidation or reduction. Spectroscopically calibrated quantum-chemical computations show that the complex has high-spin iron(II) in a pseudotetrahedral coordination environment, which features interactions with side chains of two histidines and a cysteine as well as the C═O of Gly45. In the (5)A(1) ground state, the d(z(2)) orbital is doubly occupied. Mutation of Met121 to Ala leaves the metal site in a similar environment but creates a pocket for reversible binding of small anions to the iron(II) center. Specifically, azide forms a high-spin iron(II) complex and cyanide forms a low-spin iron(II) complex.

  • Organizational Affiliation

    Department of Chemistry, University of Rochester, Rochester, New York 14618, United States.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
128Pseudomonas aeruginosa PAO1Mutation(s): 0 
Gene Names: azuPA4922
Find proteins for P00282 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore P00282 
Go to UniProtKB:  P00282
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00282
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.20 Å
  • R-Value Free: 0.277 
  • R-Value Work: 0.245 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.309α = 90
b = 98.033β = 90
c = 108.9γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-12-12
    Type: Initial release
  • Version 1.1: 2012-12-19
    Changes: Database references
  • Version 1.2: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description