The competition between chemistry and biology in assembling iron-sulfur derivatives. Molecular structures and electrochemistry. Part V. {[Fe4S4](SCysγ)4} proteins

Continuing our systematic approach to update structure/electrochemistry of the different classes of iron sulfur clusters harbored by metalloproteins (Part I, {Fe(Cys)(4)} core, Coord. Chem. Rev., 257 (2013) 1777-1805; Part II, ([Fe2S2](Cys)(4)} core, Coord. Chem. Rev., 280 (2014) 54-83; Part III, {[Fe2S2](Cys)(3)(X)} (X = Asp, Arg, His) and {[Fe2S2](Cys)(2)(His)(2)} cores, Coord. Chem. Rev., 306 (2016) 420-442 and Part IV, {[Fe3S4](Cys)(3)} core, in Metals Systems for a Sustainable Chemistry, Part 2, Inorg. Chim. Acta, 455 (2017) 319-328), we deal here with proteins containing redox-active {[Fe4S4](S-Cys(gamma))(4)} centers. Given that more than one hundred of native enzymes harboring such iron-sulfur clusters have been structurally characterized in the bacterial, archaeal and eukaryan kingdoms of life (to which an high number of structurally characterized mutants have to be added), beyond those ferredoxins clearly deputed to simple electron transfer processes (high-potential and low-potential ferredoxins), we have subdivided the remaining enzymes according to their multiple biological functions. As usual we point out those proteins which still lack electrochemical investigation in that it is often of help in elucidating the pathway mechanism responsive of the pertinent functions. Finally we have also examined structure and electrochemistry of synthetic analogs of {[Fe4S4](S-Cys(gamma))(4)} proteins. (C) 2016 Elsevier B.V. All rights reserved.