Wheel and Deal in the Mitochondrial Inner Membranes: The Tale of Cytochrome c and Cardiolipin

Figure 3

Proposed model for the interaction of cytochrome c with cardiolipin at pH values above 7. (a) Upper: structure of free Cc showing the foldon units (in red scale, PDB 1AKK [100]). Lower: the Cc-CL interaction promotes unfolding of the metalloprotein and dissociation of the axial ligand M80, thus increasing accessibility to the heme crevice. (b) Upper: structural comparison of free (in red scale, PDB 1AKK [100]) and CL-bound Cc (in blue scale, PDB 2N3B [115]). Lower: interaction of Cc with CL yields a slight difference in dynamics at the level of the Ω-loops and helix-I. The different foldon units of Cc are colored as a gradient from the most stable (dark colors) to the weakest region (light colors). The heme group is in green, and the iron atom in orange.

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