Synonyms: a 4Fe-4S iron-sulfur cluster, a 4Fe-4S center, a 4Fe-4S cluster, a 4Fe-4S iron-sulfur center, a Fe4S4 iron-sulfur center, a [4Fe-4S] iron-sulfur center, [4Fe-4S], 4Fe-4S
|Superclasses:||a cofactor → a prosthetic group → a metal-sulfur cluster → an iron-sulfur cluster|
Iron-sulfur centers consist of nonheme iron complexed to sulfur in several ways. Iron-sulfur clusters are prosthetic groups of many proteins, which function as intracellular electron carriers with a low reduction potential. In addition to their roles in electron transfer reactions, iron-sulfur clusters are also known to participate in the activation of substrates, the stabilization of radicals and structures, the protection of proteins from enzymes and the storage of iron and sulfur. In addition, they act as sensors of iron, dioxygen, the superoxide ion, and possibly nitric oxide, and participate in gene expression [Park06].
[4Fe-4S] iron-sulfur clusters feature four iron ions and four sulfide ions placed at the vertices of a cubane-type structure. The Fe centers are typically further coordinated by cysteinyl ligands.
Two main types of [4Fe-4S] iron-sulfur clusters are low-potential (bacterial-type) clusters and high-potential (HiPIP) clusters. The bacterial clusters shift between the oxidation states +1 and +2, while the HiPIP clusters shift between the oxidation states +2 and +3.
In some enzymes the [4Fe-4S] iron-sulfur clusters bind substrates and are thus classified as enzyme cofactors. For example, in radical SAM enzymes the cluster binds and reduces S-adenosylmethionine, generate a radical that interacts with the enzyme's substrate.
Chemical Formula: S4Fe4
Molecular Weight: 351.63 Daltons
Monoisotopic Molecular Weight: 351.62805116 Daltons
Standard Gibbs Free Energy of Change Formation (ΔfG'° in kcal/mol): 0.0 [Latendresse13]
Reactions known to consume the compound:
Enzymes activated by a [4Fe-4S] iron-sulfur cluster, sorted by the type of activation, are:Activator (Allosteric) of: tetrathionate reductase [Hensel99] Activator (Mechanism unknown) of: 5-thyminyl-5,6-dihydrothymine lyase [Rebeil01]
This compound has been characterized as a cofactor or prosthetic group of the following enzymes: carbon-phosphorous lyase, quinolinate synthase, formate dehydrogenase N, coproporphyrinogen III dehydrogenase, 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate synthase, biotin synthase, citrate hydro-lyase (cis-aconitate-forming), D-threo-isocitrate hydro-lyase (cis-aconitate-forming), (2R,3S)-2-methylisocitrate hydro-lyase, citrate hydro-lyase, D-threo-isocitrate hydro-lyase, succinate:quinone oxidoreductase, lipoyl synthase, 2,3-dihydroxy-3-methylvalerate hydro-lyase, 2,3-dihydroxy-isovalerate dehydratase, fumarate reductase, dimethyl sulfoxide reductase, NADH:ubiquinone oxidoreductase (H+-transporting), serine deaminase, L-serine deaminase, L-serine deaminase, sulfite reductase, menaquinol:nitrate oxidoreductase, hydrogen:menaquinone oxidoreductase, lysine 2,3-aminomutase, 23S rRNA m5U1939 methyltransferase, ubiquinol:nitrate oxidoreductase (periplasmic), 2,4-dienoyl-CoA reductase, fumarase A, tRNA m2A37 methyltransferase, 23S rRNA m2A2503 methyltransferase, protein methylthiotransferase, ribonucleoside triphosphate reductase activase, N-acetyl-phophinothricyl-L-alanyl-L-alanine P-methyltransferase, N-acetyl-phophinothricin P-methyltransferase, N-acetyl-demethylphophinothricin P-methyltransferase, N-acetyl-demethylphophinothricin-L-alanyl-L-leucine P-methyltransferase, 2-hydroxyethylphosphonate methylase, 5-hydroxybenzimidazole synthase, L-cluster synthase, L-tryptophan C2-methyltranferase, glutamate 2,3-aminomutase, 2-naphthoyl-CoA reductase, coenzyme F420H2 oxidase, cytosyl-β-D-glucuronate decarboxylase, pre-heme d1 synthase, heme synthase, 2-(3-amino-3-carboxypropyl)histidine synthase, methylene tetrahydrofolate reductase, 6-hydroxymethyl-7,8-dihydropterin 7,9-dimethyltransferase, hydrogen sulfide:ferredoxin oxidoreductase, 4-hydroxyphenylacetate decarboxylase, aminodeoxyfutalosine synthase, fumarate reductase, precorrin-3B synthase, dehypoxanthinylfutalosine cyclase, dehypoxanthinylfutalosine cyclase, tRNA-4-demethylwyosine synthase, tRNA-4-demethylwyosine synthase, 2-oxoacid:ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, 2-oxoglutarate:ferredoxin oxidoreductase, cobalt-precorrin 3 synthase, cobalt-cofactor III methyltransferase, hydrogen dehydrogenase [NAD(P)+], 2-deoxy-scyllo-inosamine dehydrogenase, daidzein reductase, (2R,3R)-3-methylornithine synthase, [Co(II) trimethylamine-specific corrinoid protein] reductase, [Co(II) dimethylamine-specific corrinoid protein] reductase, [Co(II) methylamine-specific corrinoid protein] reductase, pyruvate dehydrogenase (NADP+), corrinoid protein:5-methyltetrahydrosarcinapterin methyltransferase, dTDP-4-amino-4,6-dideoxy-D-glucose deaminase, cyclic pyranopterin monophosphate synthase, 23S rRNA (adenine2503-C8)-methyltransferase, hydrogenase, pyruvate flavodoxin oxidoreductase, nitrogenase, formylmethanofuran dehydrogenase, adenylylsulfate reductase, 2-oxoglutarate:ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, hydrogenase, nitrogenase, ferredoxin-thioredoxin reductase, pyruvate:ferredoxin oxidoreductase, Ech hydrogenase, polysulfide reductase, sulfide dehydrogenase, dissimilatory sulfite reductase, dissimilatory sulfite reductase, adenylylsulfate reductase, APS reductase, dissimilatory sulfite reductase, 2-oxobutanoate:ferredoxin oxidoreductase, β-methyl-D-malate hydro-lyase (2-methylmaleate-forming), carbon-monoxide dehydrogenase, benzoyl-CoA reductase, 7-carboxy-7-deazaguanine synthase, oxalate oxidoreductase, dimethylamine dehydrogenase, electron transfer flavoprotein-ubiquinone oxidoreductase, 4-hydroxybutyryl-CoA dehydratase, dihydrothymine dehydrogenase, dihydrouracil dehydrogenase, glutamate-tyrosine ligase, 5-thyminyl-5,6-dihydrothymine lyase, phosphomethylpyrimidine synthase, precorrin 3B synthase, 2,5-dichlorophenol reductive dehalogenase, pyruvate synthase, homoaconitate hydratase, dimethylsulfide dehydrogenase, 4-hydroxybutyryl-CoA dehydratase, (2S)-2-isopropylmalate hydro-lyase (2-isopropylmaleate-forming), nitrite reductase, nitrate reductase, nitrate reductase, nitrate reductase, ferredoxin--nitrate reductase, nitrate reductase, trimethylamine dehydrogenase, acetylene hydratase, light-independent protochlorophyllide reductase, 131-oxo- magnesium-protoporphyrin IX monomethyl ester cyclase, dissimilatory sulfite reductase, acetyl-CoA decarbonylase/synthase, benzoyl-CoA 2,3-epoxidase, phenylacetyl-CoA dehydrogenase, CoB-CoM heterodisulfide reductase, ethylbenzene dehydrogenase, ethylbenzene dehydrogenase
Park06: Park YJ, Yoo CB, Choi SY, Lee HB (2006). "Purifications and characterizations of a ferredoxin and its related 2-oxoacid:ferredoxin oxidoreductase from the hyperthermophilic archaeon, Sulfolobus solfataricus P1." J Biochem Mol Biol 39(1);46-54. PMID: 16466637
Rebeil01: Rebeil R, Nicholson WL (2001). "The subunit structure and catalytic mechanism of the Bacillus subtilis DNA repair enzyme spore photoproduct lyase." Proc Natl Acad Sci U S A 98(16);9038-43. PMID: 11470912
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