3ELL

Structure of the hemophore from Pseudomonas aeruginosa (HasAp)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.166 

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This is version 1.1 of the entry. See complete history


Literature

Structural characterization of the hemophore HasAp from Pseudomonas aeruginosa: NMR spectroscopy reveals protein-protein interactions between Holo-HasAp and hemoglobin.

Alontaga, A.Y.Rodriguez, J.C.Schonbrunn, E.Becker, A.Funke, T.Yukl, E.T.Hayashi, T.Stobaugh, J.Moenne-Loccoz, P.Rivera, M.

(2009) Biochemistry 48: 96-109

  • DOI: 10.1021/bi801860g
  • Primary Citation of Related Structures:  
    3ELL

  • PubMed Abstract: 
  • Pseudomonas aeruginosa secretes a 205 residue long hemophore (full-length HasAp) that is subsequently cleaved at the C'-terminal domain to produce mainly a 184 residue long truncated HasAp that scavenges heme [Letoffé, S., Redeker, V., and Wandersman, C. (1998) Mol ...

    Pseudomonas aeruginosa secretes a 205 residue long hemophore (full-length HasAp) that is subsequently cleaved at the C'-terminal domain to produce mainly a 184 residue long truncated HasAp that scavenges heme [Letoffé, S., Redeker, V., and Wandersman, C. (1998) Mol. Microbiol. 28, 1223-1234]. HasAp has been characterized by X-ray crystallography and in solution by NMR spectroscopy. The X-ray crystal structure of truncated HasAp revealed a polypeptide alphabeta fold and a ferriheme coordinated axially by His32 and Tyr75, with the side chain of His83 poised to accept a hydrogen bond from the Tyr75 phenolic acid group. NMR investigations conducted with full-length HasAp showed that the carboxyl-terminal tail (21 residues) is disordered and conformationally flexible. NMR spectroscopic investigations aimed at studying a complex between apo-HasAp and human methemoglobin were stymied by the rapid heme capture by the hemophore. In an effort to circumvent this problem NMR spectroscopy was used to monitor the titration of 15N-labeled holo-HasAp with hemoglobin. These studies allowed identification of a specific area on the surface of truncated HasAp, encompassing the axial ligand His32 loop that serves as a transient site of interaction with hemoglobin. These findings are discussed in the context of a putative encounter complex between apo-HasAp and hemoglobin that leads to efficient hemoglobin-heme capture by the hemophore. Similar experiments conducted with full-length 15N-labeled HasAp and hemoglobin revealed a transient interaction site in full-length HasAp similar to that observed in the truncated hemophore. The spectral perturbations observed while investigating these interactions, however, are weaker than those observed for the interactions between hemoglobin and truncated HasAp, suggesting that the disordered tail in the full-length HasAp must be proteolyzed in the extracellular milieu to make HasAp a more efficient hemophore.


    Organizational Affiliation

    Ralph N. Adams Institute for Bioanalytical Chemistry and Department of Chemistry, University of Kansas, Lawrence, Kansas 66047, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
HasAp (Heme acquisition protein HasAp)A, B184Pseudomonas aeruginosaMutation(s): 0 
Gene Names: hasApPA3407hasAFC629_08005NCTC10662_05191PERCYII40_1730
UniProt
Find proteins for O69756 (Pseudomonas aeruginosa)
Explore O69756 
Go to UniProtKB:  O69756
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM (Subject of Investigation/LOI)
Query on HEM

Download Ideal Coordinates CCD File 
C [auth A], D [auth B]PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.189 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.166 
  • Space Group: P 31
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 47.7α = 90
b = 47.7β = 90
c = 141.29γ = 120
Software Package:
Software NamePurpose
CrystalCleardata collection
CNSrefinement
CrystalCleardata reduction
XDSdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-01-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance