3LI2

Closed Conformation of HtsA Complexed with Staphyloferrin A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.168 

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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:  
    3LHS, 3LI2

  • 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 synthesizes and secretes SA into its environment to scavenge iron ...

    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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Ferrichrome ABC transporter lipoproteinA, B296Staphylococcus aureus subsp. aureus str. NewmanMutation(s): 0 
Gene Names: htsANWMN_2078
UniProt
Find proteins for A0A0H3K9U6 (Staphylococcus aureus (strain Newman))
Explore A0A0H3K9U6 
Go to UniProtKB:  A0A0H3K9U6
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SF8 (Subject of Investigation/LOI)
Query on SF8

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

Download Ideal Coordinates CCD File 
E [auth A], F [auth A], G [auth A], H [auth A]ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download Ideal Coordinates CCD File 
I [auth A]ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
FE
Query on FE

Download Ideal Coordinates CCD File 
C [auth A], J [auth B]FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
SF8 PDBBind:  3LI2 Kd: 1 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.168 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.28α = 90
b = 148.6β = 117.14
c = 52.27γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

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