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Iron–sulfur clusters are molecular ensembles of iron and sulfide. They are most often discussed in the context of the biological role for iron–sulfur proteins , which are pervasive. [ 2 ] Many Fe–S clusters are known in the area of organometallic chemistry and as precursors to synthetic analogues of the biological clusters.
Iron–sulfur proteins are proteins characterized by the presence of iron–sulfur clusters containing sulfide-linked di-, tri-, and tetrairon centers in variable oxidation states. Iron–sulfur clusters are found in a variety of metalloproteins , such as the ferredoxins , as well as NADH dehydrogenase , hydrogenases , coenzyme Q – cytochrome ...
The assembly of iron–sulfur clusters cluster begins with the production of the equivalent of a sulfur (sulfur atoms per se are not found in nature). The required sulfur atom is obtained from free cysteine by the action of so-called cysteine desulfurases. One prominent desulfurase is called IscS, a pyridoxal phosphate-dependent enzyme.
Cubane clusters are common throughout bioinorganic chemistry. Ferredoxins containing [Fe 4 S 4] iron–sulfur clusters are pervasive in nature. [1] The four iron atoms and four sulfur atoms form an alternating arrangement at the corners. The whole cluster is typically anchored by coordination of the iron atoms, usually with cysteine residues.
In 1979, Trumpower's team isolated the "oxidation factor" from bovine mitochondria and showed it was a reconstitutively-active form of the Rieske iron-sulfur protein. [2] It is a unique [2Fe-2S] cluster in that one of the two Fe atoms is coordinated by two histidine residues rather than two cysteine residues.
They participate in electron-transfer sequences. The core structure for the [Fe 4 S 4] cluster is a cube with alternating Fe and S vertices. These clusters exist in two oxidation states with a small structural change. Two families of [Fe 4 S 4] clusters are known: the ferredoxin (Fd) family and the high-potential iron–suflur protein (HiPIP ...
The active site of Mo nitrogenase is the M-cluster, a metal-sulfur cluster containing a carbide at its core. Within the biosynthesis of M-cluster, radical SAM enzyme NifB has been recognized to catalyze a carbon insertion reaction, leading to formation of a Mo/homocitrate-free precursor of M-cluster. [35]
It is an iron-sulfur transferase that contains binding sites for and clusters. ISCU contains a transit peptide , 4 beta strands , 4 alpha helixes , and 4 turns. [ 8 ] [ 9 ] Alternative splicing results in transcript variants encoding different protein isoforms that localize either to the cytosol or to the mitochondrion .