Unusual structures and unknown roles of FeS clusters in metalloenzymes seen from a resonance Raman spectroscopic perspective

The universe of known biological FeS clusters is constantly enlarging. Besides the conventional, well described [2Fe–2S], [3Fe–4S] and cubane [4Fe–4S] clusters, novel, unprecedented structures are emerging. They include unusually coordinated clusters, with additional sulfur atoms, e.g., [4Fe–5S], [5Fe–5S], [4Fe–4S]-5S-[4Fe–4S], [8Fe–7S], [8Fe–9S] and [8Fe–8S–C] and heteronuclear clusters, e.g., [Ni–4Fe–4S], [2Ni–4Fe–4S], [4Fe–4S]-[2Ru],...