O43837 · IDH3B_HUMAN
- ProteinIsocitrate dehydrogenase [NAD] subunit beta, mitochondrial
- GeneIDH3B
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids385 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Plays a structural role to facilitate the assembly and ensure the full activity of the enzyme catalyzing 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.
Activity regulation
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.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | isocitrate dehydrogenase complex (NAD+) | |
Cellular Component | mitochondrial matrix | |
Cellular Component | mitochondrion | |
Cellular Component | nucleus | |
Molecular Function | electron transfer activity | |
Molecular Function | isocitrate dehydrogenase (NAD+) activity | |
Molecular Function | magnesium ion binding | |
Molecular Function | NAD binding | |
Biological Process | isocitrate metabolic process | |
Biological Process | tricarboxylic acid cycle |
Keywords
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameIsocitrate dehydrogenase [NAD] subunit beta, mitochondrial
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionO43837
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
Disease & Variants
Involvement in disease
Retinitis pigmentosa 46 (RP46)
- Note
- DescriptionA retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.
- See alsoMIM:612572
Natural variants in RP46
Variant ID | Position(s) | Change | Description | |
---|---|---|---|---|
VAR_054851 | 132 | L>P | in RP46; dbSNP:rs137853020 |
Features
Showing features for natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_022660 | 3 | in dbSNP:rs3178817 | |||
Sequence: A → V | ||||||
Natural variant | VAR_054851 | 132 | in RP46; dbSNP:rs137853020 | |||
Sequence: L → P | ||||||
Natural variant | VAR_049781 | 166 | in dbSNP:rs11542741 | |||
Sequence: Q → H | ||||||
Natural variant | VAR_056005 | 360 | in dbSNP:rs8296 | |||
Sequence: T → A |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 467 variants from UniProt as well as other sources including ClinVar and dbSNP.
Keywords
- Disease
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for transit peptide, chain, modified residue (large scale data), modified residue.
Type | ID | Position(s) | Source | Description | |||
---|---|---|---|---|---|---|---|
Transit peptide | 1-34 | UniProt | Mitochondrion | ||||
Sequence: MAALSGVRWLTRALVSAGNPGAWRGLSTSAAAHA | |||||||
Chain | PRO_0000014444 | 35-385 | UniProt | Isocitrate dehydrogenase [NAD] subunit beta, mitochondrial | |||
Sequence: ASRSQAEDVRVEGSFPVTMLPGDGVGPELMHAVKEVFKAAAVPVEFQEHHLSEVQNMASEEKLEQVLSSMKENKVAIIGKIHTPMEYKGELASYDMRLRRKLDLFANVVHVKSLPGYMTRHNNLDLVIIREQTEGEYSSLEHESARGVIECLKIVTRAKSQRIAKFAFDYATKKGRGKVTAVHKANIMKLGDGLFLQCCEEVAELYPKIKFETMIIDNCCMQLVQNPYQFDVLVMPNLYGNIIDNLAAGLVGGAGVVPGESYSAEYAVFETGARHPFAQAVGRNIANPTAMLLSASNMLRHLNLEYHSSMIADAVKKVIKVGKVRTRDMGGYSTTTDFIKSVIGHLQTKGS | |||||||
Modified residue (large scale data) | 173 | PRIDE | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue | 199 | UniProt | N6-acetyllysine | ||||
Sequence: K |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Interaction
Subunit
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.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | O43837-2 | IDH3A PRO_0000014436 P50213 | 2 | EBI-725399, EBI-25820746 |
Protein-protein interaction databases
Miscellaneous
Structure
Sequence & Isoforms
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
This entry describes 3 isoforms produced by Alternative splicing.
O43837-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- NameB
- Length385
- Mass (Da)42,184
- Last updated2007-05-01 v2
- Checksum7324E6CC30A68EE2
O43837-2
- NameA
- Differences from canonical
- 361-385: RDMGGYSTTTDFIKSVIGHLQTKGS → SDMGGYATCHDFTEAVIAALPHP
O43837-3
- NameC
- Differences from canonical
- 1-177: MAALSGVRWLTRALVSAGNPGAWRGLSTSAAAHAASRSQAEDVRVEGSFPVTMLPGDGVGPELMHAVKEVFKAAAVPVEFQEHHLSEVQNMASEEKLEQVLSSMKENKVAIIGKIHTPMEYKGELASYDMRLRRKLDLFANVVHVKSLPGYMTRHNNLDLVIIREQTEGEYSSLEHE → MKMGERWSSLFPFPVSPSCCFLLTQ
Computationally mapped potential isoform sequences
There are 4 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A0D9SG66 | A0A0D9SG66_HUMAN | IDH3B | 145 | ||
A0A0D9SET9 | A0A0D9SET9_HUMAN | IDH3B | 83 | ||
A0A087X2E5 | A0A087X2E5_HUMAN | IDH3B | 376 | ||
A0A087WZN1 | A0A087WZN1_HUMAN | IDH3B | 387 |
Features
Showing features for alternative sequence, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_041335 | 1-177 | in isoform C | |||
Sequence: MAALSGVRWLTRALVSAGNPGAWRGLSTSAAAHAASRSQAEDVRVEGSFPVTMLPGDGVGPELMHAVKEVFKAAAVPVEFQEHHLSEVQNMASEEKLEQVLSSMKENKVAIIGKIHTPMEYKGELASYDMRLRRKLDLFANVVHVKSLPGYMTRHNNLDLVIIREQTEGEYSSLEHE → MKMGERWSSLFPFPVSPSCCFLLTQ | ||||||
Sequence conflict | 127-130 | in Ref. 6; CAB43266 | ||||
Sequence: SYDM → RTLV | ||||||
Sequence conflict | 250 | in Ref. 2; BAA91971 | ||||
Sequence: I → V | ||||||
Alternative sequence | VSP_002462 | 361-385 | in isoform A | |||
Sequence: RDMGGYSTTTDFIKSVIGHLQTKGS → SDMGGYATCHDFTEAVIAALPHP | ||||||
Sequence conflict | 385 | in Ref. 1; AAD09340 | ||||
Sequence: S → SNL |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U49283 EMBL· GenBank· DDBJ | AAB94295.1 EMBL· GenBank· DDBJ | mRNA | ||
AF023265 EMBL· GenBank· DDBJ | AAD09339.1 EMBL· GenBank· DDBJ | mRNA | ||
AF023266 EMBL· GenBank· DDBJ | AAD09340.1 EMBL· GenBank· DDBJ | mRNA | ||
AK001905 EMBL· GenBank· DDBJ | BAA91971.1 EMBL· GenBank· DDBJ | mRNA | ||
AK315641 EMBL· GenBank· DDBJ | BAG38008.1 EMBL· GenBank· DDBJ | mRNA | ||
AL049712 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
CH471133 EMBL· GenBank· DDBJ | EAX10579.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471133 EMBL· GenBank· DDBJ | EAX10580.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471133 EMBL· GenBank· DDBJ | EAX10582.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471133 EMBL· GenBank· DDBJ | EAX10583.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC001960 EMBL· GenBank· DDBJ | AAH01960.1 EMBL· GenBank· DDBJ | mRNA | ||
AL050094 EMBL· GenBank· DDBJ | CAB43266.1 EMBL· GenBank· DDBJ | mRNA |