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ESCHERICHIA COLI FERRIC HYDROXAMATE UPTAKE RECEPTOR (FHUA) IN COMPLEX DELTA TWO-ALBOMYCIN
Structural highlights
FunctionFHUA_ECOLI This receptor binds the ferrichrome-iron ligand. It interacts with the TonB protein, which is responsible for energy coupling of the ferrichrome-promoted iron transport system. Acts as a receptor for bacteriophage T5 as well as T1, phi80 and colicin M. Binding of T5 triggers the opening of a high conductance ion channel. Can also transport the antibiotic albomycin.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedOne alternative method for drug delivery involves the use of siderophore-antibiotic conjugates. These compounds represent a specific means by which potent antimicrobial agents, covalently linked to iron-chelating siderophores, can be actively transported across the outer membrane of gram-negative bacteria. These "Trojan Horse" antibiotics may prove useful as an efficient means to combat multi-drug-resistant bacterial infections. Here we present the crystallographic structures of the natural siderophore-antibiotic conjugate albomycin and the siderophore phenylferricrocin, in complex with the active outer membrane transporter FhuA from Escherichia coli. To our knowledge, this represents the first structure of an antibiotic bound to its cognate transporter. Albomycins are broad-host range antibiotics that consist of a hydroxamate-type iron-chelating siderophore, and an antibiotically active, thioribosyl pyrimidine moiety. As observed with other hydroxamate-type siderophores, the three-dimensional structure of albomycin reveals an identical coordination geometry surrounding the ferric iron atom. Unexpectedly, this antibiotic assumes two conformational isomers in the binding site of FhuA, an extended and a compact form. The structural information derived from this study provides novel insights into the diverse array of antibiotic moieties that can be linked to the distal portion of iron-chelating siderophores and offers a structural platform for the rational design of hydroxamate-type siderophore-antibiotic conjugates. Crystal structure of the antibiotic albomycin in complex with the outer membrane transporter FhuA.,Ferguson AD, Braun V, Fiedler HP, Coulton JW, Diederichs K, Welte W Protein Sci. 2000 May;9(5):956-63. PMID:10850805[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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