Crystal structures have been solved for two bacterial outer membrane proteins, FhuA and FepA, which mediate active transport of chelated iron. Analysis of ligand-induced changes in the structure of FhuA has provided our first structural insights into an active transport mechanism for a complex solute.

Spectroscopic analyses of fluorophore-labeled Escherichia coli FepA described dynamic actions of its surface loops during binding and transport of ferric enterobactin (FeEnt). When FeEnt bound to fluoresceinated FepA, in living cells or outer membrane fragments, quenching of fluorophore emissions reflected conformational motion of the external vestibular loops. We reacted Cys sulfhydryls in sev...

objective: escherichia coli o157:h7 is a gram-negative rod-shaped bacterium. e coli o157:h7 is an enterohemorrhagic (ehec) strain of the bacterium escherichia coli and a cause of foodborne illness. infection often leads to bloody diarrhea by producing a toxin called shiga toxin, which damages the intestines, and occasionally leads to kidney failure, especially in young children and elderly peop...

Yersinia enterocolitica is well equipped for siderophore piracy, encompassing the utilization of siderophores such as ferrioxamine, ferrichrome, and ferrienterochelin. In this study, we report on the molecular and functional characterization of the Yersinia fep-fes gene cluster orthologous to the Escherichia coli ferrienterochelin transport genes (fepA, fepDGC, and fepB) and the esterase gene f...

The ferric hydroxamate uptake receptor FhuA from Escherichia coli transports siderophores across the outer membrane (OM). TonB-ExbB-ExbD transduces energy from the cytoplasmic membrane to the OM by contacts between TonB and OM receptors that contain the Ton box, a consensus sequence near the N terminus. Although the Ton box is a region of known contact between OM receptors and TonB, our biophys...

Department of Chemistry, Massachusetts I 02139, USA. E-mail: [email protected]; Fax: † Electronic supplementary information (E employed in this study, iron content o characterization of GlcEnt–Amp/Amx 7–1 search for iroN sequence. Figures of HP glucosylation of Ent-PEG3-N3 11, optical a 7–10, additional antimicrobial activity a assays for FepA and IroN recognition, assays, Lcn2 effect on antibacte...