Figure3. Two conformations of the Rieske Iron-sulfur Protein (Stereo pair). Cytochrome b (salmon) and the Rieske protein in the cytochrome b position (blue) are from PDB entry 3BCC. Cytochrome c1 (orange) and the Rieske protein in cyt c1 position (yellow) are from our unsubmitted beef P6522 structure (2). Stigmatellin (green) marks the position of the Qo site, and the hemes of cytochrome b and cytchrome c1 are red. The ironsulfur cluster in each position is shown as large red and yellow balls, and H161 is solid blue (b position) or yellow (c1 position).