Ketol-acid reductoisomerase

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ketol-acid reductoisomerase
4tsk.jpg
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
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PMC articles
PubMed articles
NCBI proteins

In enzymology, ketol-acid reductoisomerase (EC 1.1.1.86) is an enzyme that catalyzes the chemical reaction

 
 
 
H+
Ketol-acid reductoisomerase
 
H+
 
 

The two substrates of this enzyme are (R)-2,3-dihydroxy-3-methylbutanoic acid and oxidised nicotinamide adenine dinucleotide phosphate (NADP+). Its products are acetolactic acid, NADPH, and a proton. [1] [2] [3] [4] [5]

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

As of late 2007, 4 structures have been solved for this class of enzymes, with PDB accession codes 1NP3, 1QMG, 1YRL, and 1YVE.

References

  1. Enzyme 1.1.1.86 at KEGG Pathway Database.
  2. 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.
  3. 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.
  4. 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 .
  5. 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.