The structure of the ferric siderophore binding protein FhuD complexed with gallichrome

Nat Struct Biol. 2000 Apr;7(4):287-91. doi: 10.1038/74048.


Siderophore binding proteins play a key role in the uptake of iron in many gram-positive and gram-negative bacteria. FhuD is a soluble periplasmic binding protein that transports ferrichrome and other hydroxamate siderophores. The crystal structure of FhuD from Escherichia coli in complex with the ferrichrome homolog gallichrome has been determined at 1.9 ¿ resolution, the first structure of a periplasmic binding protein involved in the uptake of siderophores. Gallichrome is held in a shallow pocket lined with aromatic groups; Arg and Tyr side chains interact directly with the hydroxamate moieties of the siderophore. FhuD possesses a novel fold, suggesting that its mechanisms of ligand binding and release are different from other structurally characterized periplasmic ligand binding proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / classification
  • Bacterial Outer Membrane Proteins / metabolism
  • Binding Sites
  • Carrier Proteins / chemistry*
  • Carrier Proteins / classification
  • Carrier Proteins / metabolism*
  • Crystallography, X-Ray
  • Escherichia coli / chemistry*
  • Escherichia coli Proteins*
  • Ferrichrome / analogs & derivatives*
  • Ferrichrome / metabolism*
  • Gallic Acid / metabolism*
  • Ligands
  • Membrane Proteins / chemistry*
  • Membrane Proteins / classification
  • Membrane Proteins / metabolism*
  • Membrane Transport Proteins*
  • Models, Molecular
  • Molecular Sequence Data
  • Periplasmic Binding Proteins*
  • Protein Folding
  • Protein Structure, Secondary
  • Receptors, Virus / chemistry
  • Receptors, Virus / classification
  • Receptors, Virus / metabolism
  • Structure-Activity Relationship


  • Bacterial Outer Membrane Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • FhuA protein, E coli
  • Ligands
  • Membrane Proteins
  • Membrane Transport Proteins
  • Periplasmic Binding Proteins
  • Receptors, Virus
  • fhuD protein, E coli
  • Ferrichrome
  • gallichrome
  • Gallic Acid

Associated data

  • PDB/1EFD