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Protein

Isocitrate dehydrogenase [NAD] subunit alpha, mitochondrial

Gene

IDH3A

Organism
Mesocricetus auratus (Golden hamster)
Status
Reviewed-Annotation score: Annotation score: 3 out of 5-Experimental evidence at protein leveli

Functioni

Catalytic subunit of the enzyme which catalyzes the decarboxylation of isocitrate (ICT) into alpha-ketoglutarate. The heterodimer composed of the alpha (IDH3A) and beta (IDH3B) subunits and the heterodimer composed of the alpha (IDH3A) and gamma (IDH3G) subunits, have considerable basal activity but the full activity of the heterotetramer (containing two subunits of IDH3A, one of IDH3B and one of IDH3G) requires the assembly and cooperative function of both heterodimers.By similarity

Catalytic activityi

Isocitrate + NAD+ = 2-oxoglutarate + CO2 + NADH.By similarity

Cofactori

Mg2+By similarity, Mn2+By similarityNote: Divalent metal cations; Mn2+ or Mg2+. Activity higher in presence of Mn2+ than of Mg2+. Binds 1 Mg2+ or Mn2+ ion per subunit.By similarity

Enzyme regulationi

The heterotetramer and the heterodimer composed of IDH3A and IDH3G subunits can be allosterically activated by citrate (CIT) or/and ADP, and the two activators can act independently or synergistically. The heterodimer composed of IDH3A and IDH3B subunits cannot be allosterically regulated and the allosteric regulation of the heterotetramer is through the IDH3G subunit and not the IDH3B subunit. The IDH3G subunit contains the allosteric site which consists of a CIT-binding site and an ADP-binding site, and the binding of CIT and ADP causes conformational changes at the allosteric site which are transmitted to the active site in the catalytic subunit (IDH3A) through a cascade of conformational changes at the heterodimer interface, leading to stabilization of the isocitrate-binding at the active site and thus activation of the enzyme. ATP can activate the heterotetramer and the heterodimer composed of IDH3A and IDH3G subunits at low concentrations but inhibits their activities at high concentrations, whereas ATP exhibits only inhibitory effect on the heterodimer composed of IDH3A and IDH3B subunits.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei64SubstrateBy similarity1
Binding sitei74SubstrateBy similarity1
Binding sitei95SubstrateBy similarity1

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionOxidoreductase
Biological processTricarboxylic acid cycle
LigandMagnesium, Manganese, Metal-binding, NAD

Names & Taxonomyi

Protein namesi
Recommended name:
Isocitrate dehydrogenase [NAD] subunit alpha, mitochondrialBy similarity (EC:1.1.1.41)
Alternative name(s):
Isocitric dehydrogenase subunit alphaBy similarity
NAD(+)-specific ICDH subunit alphaBy similarity
Gene namesi
Name:IDH3ABy similarity
OrganismiMesocricetus auratus (Golden hamster)
Taxonomic identifieri10036 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaCricetidaeCricetinaeMesocricetus
Proteomesi
  • UP000189706 Componenti: Genome assembly

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Mitochondrion

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_0000394308‹1 – ›134Isocitrate dehydrogenase [NAD] subunit alpha, mitochondrialAdd BLAST›134

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei37N6-succinyllysineBy similarity1
Modified residuei50PhosphothreonineBy similarity1

Keywords - PTMi

Phosphoprotein

Proteomic databases

PRIDEiP86225.

Interactioni

Subunit structurei

Heterooligomer of subunits alpha (IDH3A), beta (IDH3B), and gamma (IDH3G) in the apparent ratio of 2:1:1. The heterodimer containing one IDH3A and one IDH3B subunit and the heterodimer containing one IDH3A and one IDH3G subunit assemble into a heterotetramer (which contains two subunits of IDH3A, one of IDH3B and one of IDH3G) and further into the heterooctamer.By similarity

Structurei

3D structure databases

ProteinModelPortaliP86225.
SMRiP86225.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Family and domain databases

InterProiView protein in InterPro
IPR024084. IsoPropMal-DH-like_dom.
PfamiView protein in Pfam
PF00180. Iso_dh. 1 hit.
SMARTiView protein in SMART
SM01329. Iso_dh. 1 hit.

Sequencei

Sequence statusi: Fragments.

P86225-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MRPGVAAVAA VRIFDAAKAP IQWEERNVTA IQGPGGKWMI PPEAKGPLKT
60 70 80 90 100
PIAAGHPSMN LLLRKTFDLY ANVRPCVSIE GYKTPYTDVN IVTIRRIAEF
110 120 130
AFEYARDMAN PTALLLSAVM MLRCSDFTEE ICRR
Length:134
Mass (Da):14,881
Last modified:May 18, 2010 - v1
Checksum:i72773443217D96BB
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Non-terminal residuei11
Non-adjacent residuesi12 – 13Curated2
Non-adjacent residuesi45 – 46Curated2
Non-adjacent residuesi54 – 55Curated2
Non-terminal residuei1341

Similar proteinsi

Entry informationi

Entry nameiIDH3A_MESAU
AccessioniPrimary (citable) accession number: P86225
Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 18, 2010
Last sequence update: May 18, 2010
Last modified: September 27, 2017
This is version 31 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Caution

The order of the peptides shown is unknown.Curated

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families