Structure of the SBP FpvC in complex with Ni2+ ion from P. aeruginosa in P212121 space group

Experimental Data Snapshot

  • Resolution: 1.65 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

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A unique ferrous iron binding mode is associated with large conformational changes for the transport protein FpvC of Pseudomonas aeruginosa.

Vigouroux, A.Aumont-Nicaise, M.Boussac, A.Marty, L.Lo Bello, L.Legrand, P.Brillet, K.Schalk, I.J.Morera, S.

(2020) FEBS J 287: 295-309

  • DOI: https://doi.org/10.1111/febs.15004
  • Primary Citation of Related Structures:  
    6R3Z, 6R44, 6R5S, 6R6K, 6RU4

  • PubMed Abstract: 

    Pseudomonas aeruginosa secretes pyoverdine, a major siderophore to get access to iron, an essential nutrient. Pyoverdine scavenges ferric iron in the bacterial environment with the resulting complex internalized by bacteria. Releasing of iron from pyoverdine in the periplasm involves an iron reduction by an inner membrane reductase and two solute-binding proteins (SBPs) FpvC and FpvF in association with their ABC transporter. FpvC and FpvF belong to two different subgroups of SBPs within the structural cluster A: FpvC and FpvF were proposed to be a metal-binding protein and a ferrisiderophore-binding protein respectively. Here, we report the redox state and the binding mode of iron to FpvC. We first solved the crystal structure of FpvC bound to a fortuitous Ni 2+ by single anomalous dispersion method. Using a different protein purification strategy, we determined the structure of FpvC with manganese and iron, which binds to FpvC in a ferrous state as demonstrated by electron paramagnetic resonance. FpvC is the first example of a hexahistidine metal site among SBPs in which the Fe 2+ redox state is stabilized under aerobic conditions. Using biophysics methods, we showed that FpvC reversibly bind to a broad range of divalent ions. The structure of a mutant mimicking the apo FpvC reveals a protein in an open state with large conformational changes when compared with the metal-bound FpvC. These results highlight that the canonical metal site in FpvC is distinct from those yet described in SBPs and they provide new insights into the mechanism of PVD-Fe dissociation in P. aeruginosa.

  • Organizational Affiliation

    Institute for Integrative Biology of the Cell (I2BC), CNRS CEA Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Probable adhesion protein294Pseudomonas aeruginosa PAO1Mutation(s): 0 
Gene Names: PA2407
Find proteins for Q9I174 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore Q9I174 
Go to UniProtKB:  Q9I174
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9I174
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.65 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 43.57α = 90
b = 62.69β = 90
c = 90.54γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-07-31
    Type: Initial release
  • Version 1.1: 2019-08-07
    Changes: Data collection, Database references
  • Version 1.2: 2020-01-29
    Changes: Database references