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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.
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.
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 ...
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 ...
Iron sulfide or Iron sulphide can refer to range of chemical compounds composed of iron and sulfur. ... Iron-sulfur clusters, includes both synthetic and biological ...
The high reduction potential of the N2 cluster and the relative proximity of the other clusters in the chain enable efficient electron transfer over long distance in the protein (with transfer rates from NADH to N2 iron-sulfur cluster of about 100 μs). [12] [13] The equilibrium dynamics of Complex I are primarily driven by the quinone redox cycle.
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.
Initially, SDHA oxidizes succinate via deprotonation at the FAD binding site, forming FADH 2 and leaving fumarate, loosely bound to the active site, free to exit the protein. Electrons from FADH 2 are transferred to the SDHB subunit iron clusters [2Fe-2S],[4Fe-4S],[3Fe-4S] and tunnel along the [Fe-S] relay until they reach the [3Fe-4S] iron ...