2O68

Crystal Structure of Haemophilus influenzae Q58L mutant FbpA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The role of the synergistic phosphate anion in iron transport by the periplasmic iron-binding protein from Haemophilus influenzae.

Khan, A.G.Shouldice, S.R.Tari, L.W.Schryvers, A.B.

(2007) Biochem J 403: 43-48

  • DOI: 10.1042/BJ20061589
  • Primary Citation of Related Structures:  
    2O69, 2O68

  • PubMed Abstract: 
  • The acquisition of iron from transferrin by Gram-negative bacterial pathogens is dependent on a periplasmic ferric-ion-binding protein, FbpA. FbpA shuttles iron from the outer membrane to an inner membrane transport complex. A bound phosphate anion c ...

    The acquisition of iron from transferrin by Gram-negative bacterial pathogens is dependent on a periplasmic ferric-ion-binding protein, FbpA. FbpA shuttles iron from the outer membrane to an inner membrane transport complex. A bound phosphate anion completes the iron co-ordination shell of FbpA and kinetic studies demonstrate that the anion plays a critical role in iron binding and release in vitro. The present study was initiated to directly address the hypothesis that the synergistic anion is required for transport of iron in intact cells. A series of site-directed mutants in the anion-binding amino acids of the Haemophilus influenzae FbpA (Gln-58, Asn-175 and Asn-193) were prepared to provide proteins defective in binding of the phosphate anion. Crystal structures of various mutants have revealed that alteration of the C-terminal domain ligands (Asn-175 or Asn-193) but not the N-terminal domain ligand (Gln-58) abrogated binding of the phosphate anion. The mutant proteins were introduced into H. influenzae to evaluate their ability to mediate iron transport. All of the single site-directed mutants (Q58L, N175L and N193L) were capable of mediating iron acquisition from transferrin and from limiting concentrations of ferric citrate. The results suggest that the transport of iron by FbpA is not dependent on binding of phosphate in the synergistic anion-binding site.


    Organizational Affiliation

    Department of Microbiology and Infectious Diseases, University of Calgary, Calgary, AB, Canada T2N 4N1.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Iron-utilization periplasmic proteinA309Haemophilus influenzaeMutation(s): 1 
Gene Names: fbpAfbphitA
Find proteins for P35755 (Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd))
Explore P35755 
Go to UniProtKB:  P35755
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
FE
Query on FE

Download CCD File 
A
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.771α = 90
b = 75.736β = 90
c = 33.953γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
XFITdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-04-03
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance