Name = aconitase 1, soluble
caption =

width =
HGNCid = 117
Symbol = ACO1
AltSymbols = IREB1
EntrezGene = 48
OMIM = 100880
RefSeq = NM_002197
UniProt = P21399
ECnumber =
Chromosome = 9
Arm = p
Band = 21.1
LocusSupplementaryData =
Name = aconitase 2, mitochondrial
caption =

width =
HGNCid = 118
Symbol = ACO2
AltSymbols =
EntrezGene = 50
OMIM = 100850
RefSeq = NM_001098
UniProt = Q99798
ECnumber =
Chromosome = 22
Arm = q
Band = 13.2
LocusSupplementaryData =

Aconitase (aconitate hydratase; EC [] ) is an enzyme that catalyses the stereo-specific isomerization of citrate to isocitrate via "cis"-aconitate in the tricarboxylic acid cycle, a non-redox-active process.


By contrast with the majority of iron-sulfur proteins that function as electron carriers, the iron-sulfur cluster of aconitase reacts directly with an enzyme substrate. Aconitase has an active [Fe4S4] 2+ cluster, which may convert to an inactive [Fe3S4] + form. Three cysteine (Cys) residues have been shown to be ligands of the [Fe4S4] centre. In the active state, the labile iron ion of the [Fe4S4] cluster is not coordinated by Cys but by water molecules.

The iron-responsive element binding protein (IRE-BP) and 3-isopropylmalate dehydratase (α-isopropylmalate isomerase; EC [] ), an enzyme catalysing the second step in the biosynthesis of leucine, are known aconitase homologues. Iron regulatory elements (IREs) constitute a family of 28-nucleotide, non-coding, stem-loop structures that regulate iron storage, heme synthesis and iron uptake. They also participate in ribosome binding and control the mRNA turnover (degradation). The specific regulator protein, the IRE-BP, binds to IREs in both 5' and 3' regions, but only to RNA in the apo form, without the Fe-S cluster. Expression of IRE-BP in cultured cells has revealed that the protein functions either as an active aconitase, when cells are iron-replete, or as an active RNA-binding protein, when cells are iron-depleted. Mutant IRE-BPs, in which any or all of the three Cys residues involved in Fe-S formation are replaced by serine, have no aconitase activity, but retain RNA-binding properties.

Aconitase is inhibited by fluoroacetate, therefore fluoroacetate is poisonous.



External links

* [ 7ACN] - PDB structure of pig aconitase in complex with [Fe4S4] cluster and isocitrate
* [ 1L5J] - PDB structure of "Escherichia coli" aconitase complexed with [Fe3S4] cluster and aconitate
* [ IPR000573] - [ InterPro] entry for aconitase

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  • Aconitase — Abb.1: Tertiärstruktur der mAc des Rinds, Bos taurus, mit gebundenem α Methylis …   Deutsch Wikipedia

  • aconitase — ⇒ACONITASE, subst. fém. CHIM. Enzyme permettant la transformation de l acide aconitique en acide citrique : • De nombreux acides intermédiaires ont été identifiés chez les plantes, où certains même s accumulent en importantes quantités (acides… …   Encyclopédie Universelle

  • aconitase — aconitase. См. аконитатгидратаза. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Aconitase —   [lateinisch] die, / n, zu den Hydratasen zählendes Enzym, das bei der Isomerisierung der Zitronensäure zu Isozitronensäure am Beginn des Zitronensäurezyklus als Katalysator wirkt …   Universal-Lexikon

  • Aconitase — Aconitate hydratase Structure de l aconitase (PDB 1ACO) …   Wikipédia en Français

  • aconitase — Enzyme of the tricarboxylic acid cycle that catalyses isomerisation of citrate/isocitrate. Isoforms are found both in mitochondrial matrix and cytoplasm …   Dictionary of molecular biology

  • aconitase — noun Aconitate hydratase, an enzyme that catalyses the stereospecific isomerization of citrate to isocitrate via cis aconitate in the tricarboxylic acid cycle …   Wiktionary

  • aconitase — SYN: aconitate hydratase. * * * acon·i·tase ə kän ə .tās n an enzyme occurring in many animal and plant tissues that accelerates the conversion of citric acid first into aconitic acid and then into isocitric acid * * * acon·i·tase (ə… …   Medical dictionary

  • aconitase — acon·i·tase …   English syllables

  • aconitase — əˈkänəˌtās noun ( s) Etymology: aconitic + ase : an enzyme occurring in many animal and plant tissues that accelerates the conversion of citric acid first into aconitic acid and then into isocitric acid …   Useful english dictionary

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