Fe4S4 and Fe3S4 Ferredoxins
The ferredoxins may be further subdivided into low-potential (bacterial-type) and high-potential (HiPIP) ferredoxins.
Low- and high-potential ferredoxins are related by the following redox scheme:
The formal oxidation numbers of the iron ions can be or in low-potential ferredoxins. The oxidation numbers of the iron ions in high-potential ferredoxins can be or .
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