4Fe4S centers from ferredoxin

Two 4Fe.4S iron sulfur centers ferredoxin

Note 4 cysteine ligands on each center

Half-cell reaction:
4Fe4S ==> 4Fe4S⁺ + e^-

Midpoint redox potential: E_{m, pH 7} = -400 - -600 mV
No. of electrons: z=1
No. of protons: n=0 or 1, depending on protein, pH, pK

©Copyright 1996, Antony Crofts, University of Illinois at Urbana-Champaign, a-crofts@uiuc.edu