Ketol-acid reductoisomerase
| ketol-acid reductoisomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 Ketol-acid reductoisomerase tetramer, Alicyclobacillus acidocaldarius | |||||||||
| Identifiers | |||||||||
| EC no. | 1.1.1.86 | ||||||||
| CAS no. | 9075-02-9 | ||||||||
| 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 | ||||||||
| |||||||||
In enzymology, a ketol-acid reductoisomerase (EC 1.1.1.86) is an enzyme that catalyzes the chemical reaction
- (R)-2,3-dihydroxy-3-methylbutanoate + NADP+ (S)-2-hydroxy-2-methyl-3-oxobutanoate + NADPH + H+
Thus, the two substrates of this enzyme are (R)-2,3-dihydroxy-3-methylbutanoate and NADP+, whereas its 3 products are (S)-2-hydroxy-2-methyl-3-oxobutanoate, NADPH, and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is (R)-2,3-dihydroxy-3-methylbutanoate:NADP+ oxidoreductase (isomerizing). Other names in common use include dihydroxyisovalerate dehydrogenase (isomerizing), acetohydroxy acid isomeroreductase, ketol acid reductoisomerase, alpha-keto-beta-hydroxylacyl reductoisomerase, 2-hydroxy-3-keto acid reductoisomerase, acetohydroxy acid reductoisomerase, acetolactate reductoisomerase, dihydroxyisovalerate (isomerizing) dehydrogenase, isomeroreductase, and reductoisomerase. This enzyme participates in valine, leucine and isoleucine biosynthesis and pantothenate and coa biosynthesis.
Structural studies
[edit]As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1NP3, 1QMG, 1YRL, and 1YVE.
References
[edit]- Arfin SM, Umbarger HE (1969). "Purification and properties of the acetohydroxy acid isomeroreductase of Salmonella typhimurium". J. Biol. Chem. 244 (5): 1118–27. doi:10.1016/S0021-9258(18)91816-8. PMID 4388025.
- Hill RK, Sawada S, Arfin SM (1979). "Stereochemistry of valine and isoleucine biosynthesis. IV Synthesis, configuration, and enzymatic specificity of alpha-acetolactate and alpha-aceto-alpha-hydroxybutyrate". Bioorg. Chem. 8 (2): 175–189. doi:10.1016/0045-2068(79)90003-8.
- Kiritani K, Narise S, Wagner RP (1966). "The reductoisomerase of Neurospora crassa". J. Biol. Chem. 241 (9): 2047–2051. doi:10.1016/S0021-9258(18)96664-0.
- Satyanarayana T, Radhakrishnan AN (1965). "Biosynthesis of valine and isoleucine in plants. 3. Reductoisomerase of Phaseolus radiatus". Biochim. Biophys. Acta. 110 (2): 380–8. doi:10.1016/s0926-6593(65)80045-5. PMID 5866387.
