The binding of the ferric uptake regulation protein to a DNA fragment

Using proton NMR, we have studied the binding of a DNA fragment in double-stranded form to the ferric uptake regulation protein, Fur. We have also looked at the binding of [Cr(CN)6]3- to Fur with a view to testing whether binding is due to electrostatic interaction between Fur and the negative surface of the DNA. No competition at the DNA binding site was observed. Additionally, we have examined the binding of manganese ions to Fur in the presence of the DNA fragment and go on to discuss the likely way in which the Fur.DNA complex responds to metal-ion binding to Fur.