The Role of Divalent Transition Metal Ions in the Binding of Fur Dimer to DNA: Binding of Mn²⁺ and Co²⁺ to EC Fur dimer-DNA Complex

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other transition metal ions at elevated concentrations. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA but Zinc plays a structural role and does not activate Fur to bind DNA.