Isocitrate dehydrogenase
| Isocitrate dehydrogenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Crystallographic structure of E. coli isocitrate dehydrogenase. There are three active sites. Three isocitrates, one isocitrate in the binding site for NADP+. | |||||||||
| Identifiers | |||||||||
| EC no. | 1.1.1.42 | ||||||||
| CAS no. | 9028-48-2 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
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| isocitrate dehydrogenase (NAD+) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.1.1.41 | ||||||||
| CAS no. | 9001-58-5 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| Monomeric isocitrate dehydrogenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
crystal structure of the monomeric isocitrate dehydrogenase in complex with isocitrate and mn | |||||||||
| Identifiers | |||||||||
| Symbol | IDH | ||||||||
| Pfam | PF03971 | ||||||||
| Pfam clan | CL0270 | ||||||||
| InterPro | IPR004436 | ||||||||
| SCOP2 | 1ofg / SCOPe / SUPFAM | ||||||||
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Isocitrate dehydrogenase (IDH) (EC 1.1.1.42) and (EC 1.1.1.41) is an enzyme that catalyzes the oxidative decarboxylation of isocitrate, producing alpha-ketoglutarate (α-ketoglutarate) and CO2. This is a two-step process, which involves oxidation of isocitrate (a secondary alcohol) to oxalosuccinate (a ketone), followed by the decarboxylation of the carboxyl group beta to the ketone, forming alpha-ketoglutarate. In humans, IDH exists in three isoforms: IDH3 catalyzes the third step of the citric acid cycle while converting NAD+ to NADH in the mitochondria. The isoforms IDH1 and IDH2 catalyze the same reaction outside the context of the citric acid cycle and use NADP+ as a cofactor instead of NAD+. They localize to the cytosol as well as the mitochondrion and peroxisome.