Figure 5. Structural model of the StOFOR2-StFd complex.

(a) Structure of the complex with two ferredoxin molecules (StFd, blue) in the biological homodimer form. (b) Close-up view of the interactions and electron transfer pathway involving the TPP cofactor, [4Fe-4S] cluster in StOFOR2, and clusters I and II in StFd. The N-terminal Zn²⁺-binding domain of StFd is shown in light blue. A Zn²⁺ ion is shown as a red sphere. The residues involved in a possible interaction between StOFOR2 and StFd are shown in cyan.