... their ability to function in vivo[24]. However, the conservation of the site ligands,together with their importance for the properties of the protein in vitro, in heme binding and in oligomeriza-tion, ... affects the second hemesite, resulting in a loss of low-spin binding and an increase in high-spin heme (Fig. 1C, D).Taken together, the UV-visible and EPR data indi-cate that His46 is a key ligand ... proteins and in the wider Fur families, representedby Fur itself, the Zur and Mur regulators, and PerR,which respond to zinc, manganese and peroxide stress,respectively [33,34]. In these proteins,...