Fig. 1.

Iron-binding sites of low-(FEHR/FE0 data) and high-iron (FE30) content DpsA protein are compared. (A and C) Isolated ion-binding sites of the DpsA ferritin displayed without the protein backbone. The FOC, NI, and NII centers are encircled or boxed. The ion- and sulfate-binding sites only of the H. salinarum ferritin are displayed; iron sites are rendered in red, magnesium in yellow, sodium in blue, and sulfate in yellow/magenta. (B) Ribbon model of the quaternary high-iron structure (FE30) of the ferritin dodecamer as viewed down the threefold axis. Each of the four trimers related by twofold symmetry is in a different color. Figs. 1, 2, 3 were made with molscript (33), raster3d (34), and dino (http://cobra.mih.unibas.ch/dino/intro.php).