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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"iron-sulfur clusters"”.
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Biosynthesis of Iron-Sulfur Clusters
It is not known whether biosynthesis of [Fe-S] clusters occurs through a spontaneous self-assembly process or an enzymatic process. However, in the <I>Azotobacter</I> <I>vinelandii</I> nitrogenase system, it has been proposed that NifS and NifU are involved in the mobilization of sulfur and iron …
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Assembly of Iron-Sulfur Clusters In Vivo
Iron-sulfur [Fe-S] clusters are protein cofactors that facilitate various life-sustaining biological processes. Their in vivo assembly is accomplished by three different systems known to date. These are: the NIF system which provides [Fe-S] clusters for nitrogenase and other nitrogen-fixing …
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Biogenesis of iron-sulfur clusters and intracellular iron metabolism
Iron-sulfur ([Fe-S]) clusters represent one of natures most diverse and ubiquitous protein prosthetic groups. [Fe-S] proteins are integral for diverse biological processes. Reconstitution of apo-proteins can occur by exogenously adding excess iron and sulfide. However, due to the toxicity of iron …
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Biogenesis and Redox Transition of Iron-sulfur Clusters in Proteins
Iron-sulfur proteins comprise one of the most ubiquitous and conserved classes of proteins in biology. The diverse functions of iron-sulfur clusters in proteins range from electron transfer to redox signaling. The assembly of iron-sulfur clusters in cells requires a complex protein system and …
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Investigations of Iron–Nitrogen Bonding at Synthetic Iron–Sulfur Clusters
… chemistry of nitrogenous ligands at high-spin iron is investigated through the synthesis and characterization of a terminal imido complex of a cuboidal tetra(μ3-sulfido)tetrairon (Fe4S4) cluster. Structural, spectroscopic, and computational studies establish a dynamic interplay between Fe–N, …
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Synthesis of Isotopically Labeled Fe and S-alkylated Iron-Sulfur Clusters
… methods of synthesizing alkylated [Fe₄S₄] clusters that can serve as models of organometallic intermediates in RS enzyme catalysis. These clusters are competent for radical release and, upon oxidation, undergo an alkyl migration process to yield S-alkylated clusters. A cluster species …
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The metabolism of iron-sulfur clusters during hydrogen peroxide stress in escherichia coli
… H2O2 directly oxidizes their solvent-exposed clusters in a Fenton-like reaction. The oxidized cluster then degrades to a catalytically inactive [3Fe-4S] form. In vitro experiments indicate that H2O2 accepts two consecutive electrons during the oxidation event; as a consequence, hydroxyl …
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Electrochemical Transformation of Alkanes, Carbon Dioxide and Protons at Iron-Porphyrins and Iron-Sulfur Clusters
… generation of hydrogen using iron-sulfur cluster. Chapter 1 gives a general overview of the electrochemical techniques which underpin the work presenedt in this thesis. Chapter 2 reports the chemical and electrocatalytic oxidation of hydrocarbons to alcohols and epoxides by …
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Structural insight into the assembly of iron-sulfur clusters and their function in radical generation
… addresses two emerging areas in the study of iron-sulfur cluster biochemistry: bioassembly of iron-sulfur clusters, and their involvement in initiation of radical chemistry. The structure of a cysteine desulfurase involved in cluster bioassembly in the cyanobacterium Synechocystis PCC sp. 6803 …
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The Roles of Peroxynitrite and Superoxide in Oxidative Damage to E. Coli
… only the dehydratase enzymes containing these iron-sulfur clusters were significantly affected by peroxynitrite challenge. These iron-sulfur clusters could be repaired, and both iron storage proteins and iron import seem to be necessary for efficient repair. This enzyme inactivation led to an …
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Protein Specificity Dictates Proper Sulfur Transfer in the Biosynthesis of Thio-cofactors in Bacteria
Sulfur-containing biomolecules including iron-sulfur clusters, thio-nucleosides, and other thio-cofactors are critical players in several biological processes. The sulfur element present in these molecules is predominantly originated from L-cysteine through activation by cysteine desulfurases and …
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Isolation of in vivo intermediates in iron sulfur cluster biogenesis
Iron-sulfur clusters are simple inorganic cofactors that are ubiquitous in living systems. The assembly of iron sulfur clusters is an essential process and must be carefully controlled in order to limit the release of toxic free iron or sulfide. Thus far there are three known protein systems for …
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Prebiotic photoreduction and polymerization of cysteinyl peptides.
… in the prebiotic synthesis of cofactors, such as iron-sulfur clusters. However, cysteinyl peptides must be reduced in order to coordinate iron-sulfur clusters. Mixtures of ferric ions and cysteinyl peptides leads to the reduction of ferric to ferrous ions and the concomitant formation of disulfide …
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Chemistry related to the actives sites of the [Fe]- and [FeFe]-hydrogenases
… classes of hydrogenase all of which feature iron-containing complexes. The work contained in this thesis has two main focuses: the synthesis and characterization of novel mimics of the [Fe]-hydrogenase active site, and spectroscopic studies on the interaction of iron-sulfur clusters with CO …
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FUNCTIONAL STUDIES OF THE FE-S CLUSTER BIOGENESIS BY SUF SYSTEM
Iron-Sulfur clusters are important metal cofactors for many enzymes. Bacteria have dedicated systems for the maturation and trafficking of Fe-S clusters. The SUF (Sulfur Utilization Factor) system is the only housekeeping system in Gram-positive bacteria; whereas in Gram-negative bacteria, the SUF …
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Characterization of Cyclopropyl Synthases Involved in the Maturation of Ribosomally Synthesized and Posttranslationally Modified Peptides
… Tyr339 is critical for both the coordination of iron-sulfur clusters and chemistry and could be used as a biomarker for the discovery of other cyclopropyl synthases. This novel RiPP modification provided a reaction scope of radical S-adenosylmethionine enzymes.</p>
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Mechanism, inhibition and spectroscopy of isoprenoid biosynthesis enzymes
… 4Fe-4S cluster-containing proteins with a unique iron whose ligand is not a cysteine residue. Continuous-wave and pulsed electron paramagnetic resonance (EPR) experiments, with the help of isotope-labeled substrates, revealed the electronic structures of reaction intermediates and inhibitors bound …
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Genetic and Biochemical Characterization of the Heteromeric Dihydroorotate Dehydrogenase From Bacillus Subtilis
… formed a heteromeric DHOD holoenzyme, an iron-sulfur flavoprotein which was determined by gel filtration to be a tetramer containing 2 mol PyrDI and 2 mol PyrDII. The two subunits were also overexpressed individually and purified. Overexpressed PyrDII formed inclusion bodies and could be …
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Biophysical Investigations of the Cytosolic Iron-Sulfur Cluster Assembly Pathway Late Acting Proteins
The cytosolic iron-sulfur ([Fe-S]) cluster assembly (CIA) pathway matures cytosolic and nuclear iron-sulfur dependent proteins found in eukaryotic cells. [Fe-S] clusters are involved in life-sustaining processes such as: DNA replication and repair, transcription, translation, and nucleotide and …
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Molecular Details Of The Mitochondrial Iron Sulfur Cluster Assembly Pathway
<p>MOLECULAR DETAILS OF THE MITOCHONDRIAL IRON SULFUR CLUSTER ASSEMBLY PATHWAY</p> <p>Iron-sulfur clusters are an important class of prosthetic group involved in electron transfer, enzyme catalysis, and regulation of gene expression. Their biosynthesis requires complex machinery located within the …
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