Search results
Results From The WOW.Com Content Network
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 ...
Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted. The National Space Science Data Center (NSSDC) site has been known to host copyrighted content. Its photo gallery FAQ states that all of the images in the photo gallery are in the public domain "Unless otherwise noted."
Abell 2744, nicknamed Pandora's Cluster, is a giant galaxy cluster resulting from the simultaneous pile-up of at least four separate, smaller galaxy clusters that took place over a span of 350 million years, and is located approximately 4 billion light years from Earth. [1] The galaxies in the cluster make up less than five percent of its mass. [1]
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.
Air_&_Space_sulfur_lamps.JPG (414 × 279 pixels, file size: 34 KB, MIME type: image/jpeg) This is a file from the Wikimedia Commons . Information from its description page there is shown below.