TonB interacts with BtuF, the Escherichia coli periplasmic binding protein for cyanocobalamin.

By its direct contact with outer membrane receptor BtuB, the cytoplasmic membrane transducer TonB delivers energy that mediates cyanocobalamin uptake in Escherichia coli. This activity has been generally proposed to be the role of TonB in cyanocobalamin uptake. We now report the discovery and characterization of interactions between TonB and periplasmic binding protein BtuF.

The limitations of point of care testing for pandemic influenza: what clinicians and public health professionals need to know.

As the world prepares for the next influenza pandemic, governments have made significant funding commitments to vaccine development and antiviral stockpiling. While these are essential components to pandemic response, rapid and accurate diagnostic testing remains an often neglected cornerstone of pandemic influenza preparedness. Clinicians and Public Health Practitioners need to understand the benefits and drawbacks of different influenza tests in both seasonal and pandemic settings.

Interactions between TonB from Escherichia coli and the periplasmic protein FhuD.

For uptake of ferrichrome into bacterial cells, FhuA, a TonB-dependent outer membrane receptor of Escherichia coli, is required. The periplasmic protein FhuD binds and transfers ferrichrome to the cytoplasmic membrane-associated permease FhuB/C. We exploited phage display to map protein-protein interactions in the E.

Phage display reveals multiple contact sites between FhuA, an outer membrane receptor of Escherichia coli, and TonB.

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 biophysical studies established that TonB binds to FhuA through multiple regions of interaction.