title: The structure of the ferric siderophore binding protein FhuD complexed with gallichrome.
abstract: 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.
authors.affiliation: Department of Biological Sciences, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, Canada T2N 1N4.
authors.forename: T E
authors.initials: TE
authors.lastname: Clarke
authors.forename: S Y
authors.initials: SY
authors.lastname: Ku
authors.forename: D R
authors.initials: DR
authors.lastname: Dougan
authors.forename: H J
authors.initials: HJ
authors.lastname: Vogel
authors.forename: L W
authors.initials: LW
authors.lastname: Tari
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D005291:Ferrichrome / Q000031:analogs & derivatives* / Q000378:metabolism*; D005707:Gallic Acid / Q000378:metabolism*; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D033902:Periplasmic Binding Proteins; D017510:Protein Folding; D017433:Protein Structure, Secondary; D011991:Receptors, Virus / Q000737:chemistry / Q000145:classification / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C050900:FhuA protein, E coli; D008024:Ligands; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033902:Periplasmic Binding Proteins; D011991:Receptors, Virus; C069969:fhuD protein, E coli; D005291:Ferrichrome; C407026:gallichrome; D005707:Gallic Acid