Structure of the SBP FpvC from pseudomonas aeruginosa in complex with Fe(II)

Experimental Data Snapshot

  • Resolution: 2.75 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.192 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


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
Adhesion protein
A, B
294Pseudomonas aeruginosaMutation(s): 0 
Gene Names: psaAC0044_17990CAZ10_34375DZ962_30765NCTC13719_02701PAMH19_5875
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
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 2.75 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.192 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.01α = 90
b = 44.19β = 95.06
c = 179.76γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

View Full Validation Report

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: 2019-09-25
    Changes: Data collection, Database references, Source and taxonomy
  • Version 1.3: 2020-01-29
    Changes: Database references