Figure 6 - full size

 

Figure 6.
Figure 6. C^a superposition of the plug domains in FecA, FepA and FhuA. The structures of FecA[apo] (gold), FepA (magenta) and unliganded FhuA (light blue) were used for the superposition. The TonB box motifs of FecA[apo] and FepA are circled.

The above figure is reprinted by permission from Elsevier: J Mol Biol (2003, 332, 353-368) copyright 2003.