|PROSITE documentation PDOC00389|
Isocitrate dehydrogenase (IDH) [1,2] is an important enzyme of carbohydrate metabolism which catalyzes the oxidative decarboxylation of isocitrate into α-ketoglutarate. IDH is either dependent on NAD+ (EC 184.108.40.206) or on NADP+ (EC 220.127.116.11). In eukaryotes there are at least three isozymes of IDH: two are located in the mitochondrial matrix (one NAD+-dependent, the other NADP+-dependent), while the third one (also NADP+-dependent) is cytoplasmic. In Escherichia coli the activity of a NADP+-dependent form of the enzyme is controlled by the phosphorylation of a serine residue; the phosphorylated form of IDH is completely inactivated.
3-isopropylmalate dehydrogenase (EC 18.104.22.168) (IMDH) [3,4] catalyzes the third step in the biosynthesis of leucine in bacteria and fungi, the oxidative decarboxylation of 3-isopropylmalate into 2-oxo-4-methylvalerate.
These enzymes are evolutionary related [1,3,4,5]. The best conserved region of these enzymes is a glycine-rich stretch of residues located in the C-terminal section. We have used this region as a signature pattern.Last update:
December 2004 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Hurley J.H. Thorsness P.E. Ramalingam V. Helmers N.H. Koshland D.E. Jr. Stroud R.M.|
|Title||Structure of a bacterial enzyme regulated by phosphorylation, isocitrate dehydrogenase.|
|Source||Proc. Natl. Acad. Sci. U.S.A. 86:8635-8639(1989).|
|2||Authors||Cupp J.R. McAlister-Henn L.|
|Title||NAD(+)-dependent isocitrate dehydrogenase. Cloning, nucleotide sequence, and disruption of the IDH2 gene from Saccharomyces cerevisiae.|
|Source||J. Biol. Chem. 266:22199-22205(1991).|
|3||Authors||Imada K. Sato M. Tanaka N. Katsube Y. Matsuura Y. Oshima T.|
|Title||Three-dimensional structure of a highly thermostable enzyme, 3-isopropylmalate dehydrogenase of Thermus thermophilus at 2.2 A resolution.|
|Source||J. Mol. Biol. 222:725-738(1991).|
|4||Authors||Zhang T. Koshland D.E. Jr.|
|Title||Modeling substrate binding in Thermus thermophilus isopropylmalate dehydrogenase.|
|Source||Protein Sci. 4:84-92(1995).|
|5||Authors||Tipton P.A. Beecher B.S.|
|Title||Tartrate dehydrogenase, a new member of the family of metal-dependent decarboxylating R-hydroxyacid dehydrogenases.|
|Source||Arch. Biochem. Biophys. 313:15-21(1994).|