2Q8Q

Crystal Structure of S. aureus IsdE complexed with heme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Heme Coordination by Staphylococcus aureus IsdE.

Grigg, J.C.Vermeiren, C.L.Heinrichs, D.E.Murphy, M.E.

(2007) J Biol Chem 282: 28815-28822

  • DOI: 10.1074/jbc.M704602200
  • Primary Citation of Related Structures:  
    2Q8P, 2Q8Q

  • PubMed Abstract: 
  • Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S ...

    Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single alpha-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met(78) and His(229). Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His(229) is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.


    Organizational Affiliation

    Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Iron-regulated surface determinant EA260Staphylococcus aureus subsp. aureus N315Mutation(s): 0 
Gene Names: isdAisdEsirFSA0980
UniProt
Find proteins for Q7A652 (Staphylococcus aureus (strain N315))
Explore Q7A652 
Go to UniProtKB:  Q7A652
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.205 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.219α = 90
b = 64.219β = 90
c = 144.993γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-07-31
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Source and taxonomy, Version format compliance
  • Version 1.2: 2017-10-18
    Changes: Refinement description