3LI2

Closed Conformation of HtsA Complexed with Staphyloferrin A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.165 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The Staphylococcus aureus siderophore receptor HtsA undergoes localized conformational changes to enclose staphyloferrin A in an arginine-rich binding pocket.

Grigg, J.C.Cooper, J.D.Cheung, J.Heinrichs, D.E.Murphy, M.E.

(2010) J.Biol.Chem. 285: 11162-11171

  • DOI: 10.1074/jbc.M109.097865
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Staphylococcus aureus uses several efficient iron acquisition strategies to overcome iron limitation. Recently, the genetic locus encoding biosynthetic enzymes for the iron chelating molecule, staphyloferrin A (SA), was determined. S. aureus synthesi ...

    Staphylococcus aureus uses several efficient iron acquisition strategies to overcome iron limitation. Recently, the genetic locus encoding biosynthetic enzymes for the iron chelating molecule, staphyloferrin A (SA), was determined. S. aureus synthesizes and secretes SA into its environment to scavenge iron. The membrane-anchored ATP binding cassette-binding protein, HtsA, receives the ferric-chelate for import into the cell. Recently, we determined the apoHtsA crystal structure, the first siderophore receptor from gram-positive bacteria to be structurally characterized. Herein we present the x-ray crystal structure of the HtsA-ferric-SA complex. HtsA adopts a class III binding protein fold composed of separate N- and C-terminal domains bridged by a single alpha-helix. Recombinant HtsA can efficiently sequester ferric-SA from S. aureus culture supernatants where it is bound within the pocket formed between distinct N- and C-terminal domains. A basic patch composed mainly of six Arg residues contact the negatively charged siderophore, securing it within the pocket. The x-ray crystal structures from two different ligand-bound crystal forms were determined. The structures represent the first structural characterization of an endogenous alpha-hydroxycarboxylate-type siderophore-receptor complex. One structure is in an open form similar to apoHtsA, whereas the other is in a more closed conformation. The conformational change is highlighted by isolated movement of three loops within the C-terminal domain, a domain movement unique to known class III binding protein structures.


    Organizational Affiliation

    Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ferrichrome ABC transporter lipoprotein
A, B
296Staphylococcus aureus (strain Newman)Mutation(s): 0 
Find proteins for A0A0H3K9U6 (Staphylococcus aureus (strain Newman))
Go to UniProtKB:  A0A0H3K9U6
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

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Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
SF8
Query on SF8

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Download CCD File 
A, B
(2R)-2-(2-{[(1R)-1-carboxy-4-{[(3S)-3,4-dicarboxy-3-hydroxybutanoyl]amino}butyl]amino}-2-oxoethyl)-2-hydroxybutanedioic acid
Staphyloferrin A
C17 H24 N2 O14
VJSIXUQLTJCRCS-DFQXCPINSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A, B
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
SF8Kd: ~1 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.165 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 52.280α = 90.00
b = 148.600β = 117.14
c = 52.270γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance