Isocitrate dehydrogenase NADP-dependent, monomeric (IPR004436)

Short name: Isocitrate_DH_NADP_mono

Overlapping homologous superfamilies


Family relationships



This family of enzymes catalyses the NADP(+)-dependent oxidative decarboxylation of isocitrate to form 2-oxoglutarate, CO2, and NADPH within the Krebs cycle (EC: Thus this enzyme supplies the cell with a key intermediate in energy metabolism, and precursors for biosynthetic pathways. The activity of this enzyme, which is controlled by phosphorylation, helps regulate carbon flux between the Krebs cycle and the glyoxylate bypass, which is an alternate route that accumulates carbon for biosynthesis when acetate is the sole carbon source for growth [PMID: 7836312]. The phosphorylation state of this enzyme is controlled by isocitrate dehydrogenase kinase/phosphatase. This family has been found in a number of bacterial species including Azotobacter vinelandii, Corynebacterium glutamicum, Rhodomicrobium vannielii, and Neisseria meningitidis.

The structure of isocitrate dehydrogenase from Azotobacter vinelandii (P16100) has been determined [PMID: 12467571]. This molecule consists of two distinct domains, a small domain and a large domain, with a folding topology similar to that of dimeric isocitrate dehydrogenase from Escherichia coli (P08200). The structure of the large domain repeats a motif observed in the dimeric enzyme. Such a fusional structure by domain duplication enables a single polypeptide chain to form a structure at the catalytic site that is homologous to the dimeric enzyme, the catalytic site of which is located at the interface of two identical subunits.

GO terms

Biological Process

GO:0055114 oxidation-reduction process
GO:0006099 tricarboxylic acid cycle

Molecular Function

GO:0004450 isocitrate dehydrogenase (NADP+) activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.