Characterization of the DNA- and metal-binding properties of Vibrio anguillarum fur reveals conservation of a structural Zn2(+) ion

The ferric uptake regulator, Fur, represses iron uptake and siderophore bio synthetic genes under iron-replete conditions. Here we report in vitro solu tion studies on Vibrio anguillarum Fur binding to the consensus 19-bp Esche richia coli iron box in the presence of several divalent metals. We found t hat V. anguillarum Fur binds the iron box in the presence of Mn2+, Co2+, Cd 2+, and to a lesser extent Ni2+ but, unlike E. coli Fur, not in the presenc e of Zn2+. We also found that V. anguillarum Fur contains a structural zinc ion that is necessary yet alone is insufficient for DNA binding.