ILV3 encodes mitochondrial dihydroxy-acid dehydratase (DHAD, EC 4.2.1.9) of Saccharomyces cerevisiae, an IlvD/EDD-family enzyme carrying one [2Fe-2S] cluster per subunit and Mg2+. In the mitochondrial matrix it dehydrates 2,3-dihydroxyisovalerate to 2-oxoisovalerate and 2,3-dihydroxy-3-methylvalerate to (S)-3-methyl-2-oxopentanoate, the third step shared by valine and isoleucine biosynthesis and the source of the 2-oxoisovalerate used for leucine synthesis. Because it depends on mitochondrial Fe/S cluster assembly, Ilv3 activity collapses under iron limitation, lowering alpha-isopropylmalate and thereby Leu3-dependent transcription (e.g. of LEU1); Ilv3 activity is widely used as a reporter of mitochondrial [2Fe-2S] biogenesis. ilv3 mutants require isoleucine and valine.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MODIFY | Summary: InterPro (IPR020558, DHAD/6-phosphogluconate dehydratase signature) mapped to root 'catalytic activity'; uninformative for an assayed dihydroxy-acid dehydratase. Proposed replacements: dihydroxy-acid dehydratase activity Supporting Evidence: PMID:20008079 the activity of Ilv3 was virtually undetectable in wild-type cells upon iron depletion |
| GO:0004160 dihydroxy-acid dehydratase activity | EXP PMID:20008079 Iron regulation through the back door: iron-dependent metabo... | ACCEPT | Summary: Ilv3 dihydroxy-acid dehydratase activity was measured in mitochondria and found to be lost under iron limitation (Fe/S-dependent). Core MF. Supporting Evidence: PMID:20008079 the activity of Ilv3 was virtually undetectable in wild-type cells upon iron depletion PMID:20008079 Branched-chain amino acid biosynthesis contains two iron-dependent enzymes, the Fe/S proteins Ilv3 (mitochondrial dihydroxy-acid dehydratase) and Leu1 |
| GO:0004160 dihydroxy-acid dehydratase activity | EXP PMID:27532773 Role of Nfu1 and Bol3 in iron-sulfur cluster transfer to mit... | ACCEPT | Summary: Melber et al. assayed Ilv3 activity in purified mitochondria of wild type and nfu1 mutants; activity independent of Nfu1, consistent with a [2Fe-2S] enzyme. Supporting Evidence: PMID:27532773 Ilv3 activity assay using wild-type and nfu1Ξ purified mitochondria along with wild-type overexpressing Ilv3 as a control PMID:27532773 Thus, Nfu1 does not appear to be important for the function of the [2Fe-2S] Ilv3 enzyme. |
| GO:0004160 dihydroxy-acid dehydratase activity | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA from PTN000470221 (IlvD family); Ilv3 is itself an experimental source. Correct, core. Supporting Evidence: PMID:20008079 the activity of Ilv3 was virtually undetectable in wild-type cells upon iron depletion |
| GO:0004160 dihydroxy-acid dehydratase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (ARBA, IPR004404, RHEA:24809/27694, EC 4.2.1.9); correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0004160 dihydroxy-acid dehydratase activity | IMP PMID:14124940 GENETIC AND BIOCHEMICAL ANALYSIS OF ISOLEUCINE-VALINE MUTANT... | ACCEPT | Summary: Kakar & Wagner 1964 correlated ilv3 isoleucine-valine auxotrophs with loss of dihydroxy-acid dehydratase. Only the title is cached; classical gene-enzyme assignment, defer to curator. Supporting Evidence: PMID:14124940 GENETIC AND BIOCHEMICAL ANALYSIS OF ISOLEUCINE-VALINE MUTANTS OF YEAST file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0004160 dihydroxy-acid dehydratase activity | ISS GO_REF:0000024 | ACCEPT | Summary: Sequence-similarity transfer from E. coli IlvD (P05791), used by UniProt for the isoleucine-branch substrate; consistent with direct assays on Ilv3. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt Evidence={ECO:0000250|UniProtKB:P05791}; |
| GO:0004160 dihydroxy-acid dehydratase activity | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways BRANCHED-CHAIN-AA-SYN-PWY-1 (superpathway of branched chain amino acid biosynthesis). Ilv3 dehydrates 2,3-dihydroxy-acids to 2-keto acids (step 3/4); MF correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0004160 dihydroxy-acid dehydratase activity | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways ILEUSYN-PWY-1 (L-isoleucine biosynthesis I (from threonine)). Ilv3 dehydrates (2R,3R)-2,3-dihydroxy-3-methylpentanoate in this branch; correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0004160 dihydroxy-acid dehydratase activity | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways VALSYN-PWY (L-valine biosynthesis). Ilv3 dehydrates 2,3-dihydroxyisovalerate to 2-oxoisovalerate; correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0005739 mitochondrion | EXP PMID:20008079 Iron regulation through the back door: iron-dependent metabo... | ACCEPT | Summary: Ilv3 activity was determined in isolated mitochondria; the paper describes Ilv3 as the mitochondrial DHAD. Supporting Evidence: PMID:20008079 Branched-chain amino acid biosynthesis contains two iron-dependent enzymes, the Fe/S proteins Ilv3 (mitochondrial dihydroxy-acid dehydratase) and Leu1 |
| GO:0005739 mitochondrion | EXP PMID:22954227 Cytosolic re-localization and optimization of valine synthes... | ACCEPT | Summary: Brat et al. needed to delete the mitochondrial targeting sequence to relocate Ilv3 to the cytosol, showing the native enzyme is in the mitochondrial matrix. Supporting Evidence: PMID:22954227 Isobutanol production could be improved by re-locating the valine biosynthesis enzymes Ilv2, Ilv5 and Ilv3 from the mitochondrial matrix into the cytosol PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:0005739 mitochondrion | HDA PMID:14576278 The proteome of Saccharomyces cerevisiae mitochondria. | ACCEPT | Summary: Ilv3 detected in the mass-spectrometric proteome of highly purified mitochondria (Sickmann et al.); consistent with its N-terminal targeting and low-throughput data. Supporting Evidence: PMID:14576278 The proteins of highly pure yeast mitochondria were separated by several independent methods and analyzed by tandem MS file:yeast/ILV3/ILV3-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion |
| GO:0005739 mitochondrion | HDA PMID:16823961 Toward the complete yeast mitochondrial proteome: multidimen... | ACCEPT | Summary: Ilv3 detected in the PROMITO multidimensional mitochondrial proteome; consistent with its N-terminal targeting and low-throughput data. Supporting Evidence: PMID:16823961 A total of 851 different proteins (PROMITO dataset) were identified file:yeast/ILV3/ILV3-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion |
| GO:0005739 mitochondrion | HDA PMID:24769239 Quantitative variations of the mitochondrial proteome and ph... | ACCEPT | Summary: Ilv3 detected in the quantitative proteome of isolated mitochondria under fermentative/respiratory growth; consistent with its N-terminal targeting and low-throughput data. Supporting Evidence: PMID:24769239 we performed an overall quantitative proteomic and phosphoproteomic study of isolated mitochondria file:yeast/ILV3/ILV3-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion |
| GO:0005739 mitochondrion | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA (PTN001077098, Ilv3 as source); fungal DHADs are mitochondrial. Correct. Supporting Evidence: PMID:20008079 Branched-chain amino acid biosynthesis contains two iron-dependent enzymes, the Fe/S proteins Ilv3 (mitochondrial dihydroxy-acid dehydratase) and Leu1 |
| GO:0005739 mitochondrion | IEA GO_REF:0000044 | ACCEPT | Summary: UniProt subcellular location mapped to GO; correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt SUBCELLULAR LOCATION: Mitochondrion |
| GO:0005829 cytosol | RCA GO_REF:0000123 | REMOVE | Summary: is_active_in cytosol from YeastPathways BRANCHED-CHAIN-AA-SYN-PWY-1 (superpathway of branched chain amino acid biosynthesis). YeastPathways defaults its reactions to the cytosol; for Ilv3 this contradicts the experimental location. Ilv3 resides in the mitochondrial matrix; only engineered presequence-less versions are cytosolic. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol PMID:22954227 Isobutanol production could be improved by re-locating the valine biosynthesis enzymes Ilv2, Ilv5 and Ilv3 from the mitochondrial matrix into the cytosol |
| GO:0005829 cytosol | RCA GO_REF:0000123 | REMOVE | Summary: is_active_in cytosol from YeastPathways ILEUSYN-PWY-1 (L-isoleucine biosynthesis I (from threonine)). YeastPathways defaults its reactions to the cytosol; for Ilv3 this contradicts the experimental location. Native Ilv3 is a mitochondrial matrix Fe/S enzyme. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol PMID:20008079 Branched-chain amino acid biosynthesis contains two iron-dependent enzymes, the Fe/S proteins Ilv3 (mitochondrial dihydroxy-acid dehydratase) and Leu1 |
| GO:0005829 cytosol | RCA GO_REF:0000123 | REMOVE | Summary: is_active_in cytosol from YeastPathways VALSYN-PWY (L-valine biosynthesis). YeastPathways defaults its reactions to the cytosol; for Ilv3 this contradicts the experimental location. Valine biosynthesis is compartmentalised in the matrix. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:0009082 branched-chain amino acid biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA; correct, Ilv3 catalyses the shared third step of Ile and Val synthesis (and supplies 2-oxoisovalerate for Leu). Supporting Evidence: PMID:20008079 Synthesis of alpha-isopropylmalate involves the iron-sulfur protein Ilv3, which is inactivated under iron deficiency PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:0009082 branched-chain amino acid biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro IPR004404 mapping; correct. Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
| GO:0009082 branched-chain amino acid biosynthetic process | IMP PMID:14124940 GENETIC AND BIOCHEMICAL ANALYSIS OF ISOLEUCINE-VALINE MUTANT... | ACCEPT | Summary: ilv3 mutants are isoleucine-valine auxotrophs (title-only cache; classical result). Defer to curator. Supporting Evidence: PMID:14124940 GENETIC AND BIOCHEMICAL ANALYSIS OF ISOLEUCINE-VALINE MUTANTS OF YEAST |
| GO:0009082 branched-chain amino acid biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways BRANCHED-CHAIN-AA-SYN-PWY-1 (superpathway of branched chain amino acid biosynthesis). Ilv3 catalyses a shared step of Ile/Val (and Leu precursor) synthesis. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:0009099 L-valine biosynthetic process | IEA GO_REF:0000041 | ACCEPT | Summary: UniPathway (L-valine biosynthesis step 3/4); correct. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:0009099 L-valine biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways VALSYN-PWY (L-valine biosynthesis). Correct: Ilv3 produces 2-oxoisovalerate, the valine precursor. Supporting Evidence: PMID:22954227 The anabolic reactions are part of valine biosynthesis and are located in the mitochondrial matrix, whereas the Ehrlich pathway reactions take place in the cytosol |
| GO:1901705 L-isoleucine biosynthetic process | RCA GO_REF:0000123 | ACCEPT | Summary: RCA from YeastPathways ILEUSYN-PWY-1 (L-isoleucine biosynthesis I (from threonine)). Correct: Ilv3 produces (S)-3-methyl-2-oxopentanoate, the isoleucine precursor (step 3/4). Supporting Evidence: file:yeast/ILV3/ILV3-uniprot.txt RecName: Full=Dihydroxy-acid dehydratase, mitochondrial |
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Download this section (compressed HTML)Experiment: Measure Ilv3 activity and 55Fe incorporation in isolated mitochondria from strains lacking individual late ISC factors (Isa1/Isa2, Iba57, Bol1, Grx5).
Hypothesis: Ilv3 [2Fe-2S] cluster insertion requires a specific late-acting ISC targeting factor distinct from Nfu1/Bol3.
Dihydroxyacid dehydratase; putative 2Fe-2S protein; catalyzes third step in the common pathway leading to biosynthesis of branched-chain amino acids
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