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 

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:  

  • 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 i ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Iron-regulated surface determinant E
A
260Staphylococcus aureus (strain N315)Mutation(s): 0 
Gene Names: isdE (sirF)
Find proteins for Q7A652 (Staphylococcus aureus (strain N315))
Go to UniProtKB:  Q7A652
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A
PROTOPORPHYRIN IX CONTAINING FE
HEME
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 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 64.219α = 90.00
b = 64.219β = 90.00
c = 144.993γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data collection
DENZOdata reduction
SCALEPACKdata scaling
MOLREPphasing
PDB_EXTRACTdata extraction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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