Figure 6: A scheme for zinc-dependent changes in the binding mode of Zur on zitB DNA.
From: Zinc-dependent regulation of zinc import and export genes by Zur
A structural model for the Zur2-DNA (25 bp) complex (a) and a model for Zur4-DNA (33 bp) complex (b). The blue regions in DNA represent the 15 bp Zur-box motif. The two figures were prepared with the same DNA orientation, to show the distinct binding modes of dimeric versus tetrameric Zur. (c) A schematic model for the change in the binding mode of Zur on zitB promoter region as zinc level increases. The dimeric Zur with three high-affinity zinc-binding sites occupied by zinc at femtomolar range (Zn3Zur)2 was indicated in red, whereas the oligomers of dimeric Zur with possibly more zinc binding at low-affinity site(s) were presented in purple.
