Gene Symbol: ilvC
Description: ketol-acid reductoisomerase, NAD(P)-binding
Alias: ECK3766, JW3747
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Rane M, Calvo K. Reversal of the nucleotide specificity of ketol acid reductoisomerase by site-directed mutagenesis identifies the NADPH binding site. Arch Biochem Biophys. 1997;338:83-9 pubmed
    ..3 microM and 7.2 min for the wild-type enzyme. By altering these four amino acids, the specificity constants for NADH and NADPH are almost exactly reversed in the mutant relative to the wild type. ..
  2. Brandes N, Rinck A, Leichert L, Jakob U. Nitrosative stress treatment of E. coli targets distinct set of thiol-containing proteins. Mol Microbiol. 2007;66:901-14 pubmed
    ..Of the 10 proteins that we identified, six (AtpA, AceF, FabB, GapA, IlvC, TufA) have been shown to harbour functionally important thiol groups and are encoded by genes that are considered ..
  3. McCourt J, Tyagi R, Guddat L, Biou V, Duggleby R. Facile crystallization of Escherichia coli ketol-acid reductoisomerase. Acta Crystallogr D Biol Crystallogr. 2004;60:1432-4 pubmed
    ..Thus, the enzyme is remarkably easy to crystallize. Most of the crystals diffract poorly but several data sets were collected at better than 3.2 A resolution; attempts to phase them are currently in progress. ..
  4. Tyagi R, Duquerroy S, Navaza J, Guddat L, Duggleby R. The crystal structure of a bacterial class II ketol-acid reductoisomerase: domain conservation and evolution. Protein Sci. 2005;14:3089-100 pubmed
    ..This contrasts with P. aeruginosa KARI, which forms a dodecamer, and spinach KARI, a dimer. In the E. coli KARI tetramer, a novel subunit-to-subunit interacting surface is formed by a symmetrical pair of bulbous protrusions. ..
  5. Schulz A, Spönemann P, Kocher H, Wengenmayer F. The herbicidally active experimental compound Hoe 704 is a potent inhibitor of the enzyme acetolactate reductoisomerase. FEBS Lett. 1988;238:375-8 pubmed
    ..The inhibition was time-dependent and competitive with the enzyme's substrate, acetolactate. This report establishes acetolactate reductoisomerase as a new target for a herbicidal compound. ..
  6. Tyagi R, Lee Y, Guddat L, Duggleby R. Probing the mechanism of the bifunctional enzyme ketol-acid reductoisomerase by site-directed mutagenesis of the active site. FEBS J. 2005;272:593-602 pubmed
    ..Our mechanism explains why the two activities must occur in a single active site without release of a 2-ketoacid and provides a rationale for the requirement for NADPH by the isomerase. ..
  7. Opel M, Hatfield G. DNA supercoiling-dependent transcriptional coupling between the divergently transcribed promoters of the ilvYC operon of Escherichia coli is proportional to promoter strengths and transcript lengths. Mol Microbiol. 2001;39:191-8 pubmed vitro transcription system to demonstrate transcriptional coupling between the divergently transcribed ilvY and ilvC promoters of the ilvYC operon of Escherichia coli...
  8. Brinkmann Chen S, Flock T, Cahn J, Snow C, Brustad E, McIntosh J, et al. General approach to reversing ketol-acid reductoisomerase cofactor dependence from NADPH to NADH. Proc Natl Acad Sci U S A. 2013;110:10946-51 pubmed publisher
    ..High-resolution structures of a wild-type/variant pair reveal the molecular basis of the cofactor switch. ..
  9. Aldea M, Maples V, Kushner S. Generation of a detailed physical and genetic map of the ilv-metE-udp region of the Escherichia coli chromosome. J Mol Biol. 1988;200:427-38 pubmed

More Information


  1. Wek R, Hatfield G. Nucleotide sequence and in vivo expression of the ilvY and ilvC genes in Escherichia coli K12. Transcription from divergent overlapping promoters. J Biol Chem. 1986;261:2441-50 pubmed
    The ilvC gene of Escherichia coli K12 encodes acetohydroxy acid isomeroreductase, the second enzyme in the parallel isoleucine-valine biosynthetic pathway...
  2. Gray J, Calhoun D. Absence of significant membrane localization of the proteins coded by the ilvGEDAC genes of Escherichia coli K-12. J Bacteriol. 1982;151:119-26 pubmed
    ..In this work, the identity of the ilvC gene product, alpha-acetohydroxy acid isomeroreductase, was confirmed by demonstrating its induction by the ..
  3. Island M, Wei B, Kadner R. Structure and function of the uhp genes for the sugar phosphate transport system in Escherichia coli and Salmonella typhimurium. J Bacteriol. 1992;174:2754-62 pubmed
  4. Hill C, Duggleby R. Purified recombinant Escherichia coli ketol-acid reductoisomerase is unsuitable for use in a coupled assay of acetohydroxyacid synthase activity due to an unexpected side reaction. Protein Expr Purif. 1999;15:57-61 pubmed
    ..Although relatively slow, this side reaction is high enough to prohibit the use of this enzyme in a coupled assay for acetohydroxyacid synthase. ..
  5. Aulabaugh A, Schloss J. Oxalyl hydroxamates as reaction-intermediate analogues for ketol-acid reductoisomerase. Biochemistry. 1990;29:2824-30 pubmed
    ..In the absence of Mg2+ or Mn2+, IpOHA does not exhibit time-dependent inhibition of the reductoisomerase.(ABSTRACT TRUNCATED AT 250 WORDS) ..
  6. Opel M, Arfin S, Hatfield G. The effects of DNA supercoiling on the expression of operons of the ilv regulon of Escherichia coli suggest a physiological rationale for divergently transcribed operons. Mol Microbiol. 2001;39:1109-15 pubmed
    ..As DNA supercoiling-dependent transcriptional coupling between the promoters of other divergently transcribed operons is investigated, additional global gene regulatory mechanisms and physiological roles are sure to emerge. ..
    ..The significance of these findings with respect to the valine-sensitivity of E. coli K-12 and the regulation of the biosynthesis of isoleucine and valine by this organism are discussed. ..
  8. Ratzkin B, Arfin S, Umbarger H. Isoleucine and valine metabolism in Escherichia coli. 18. Induction of acetohydroxy acid isomeroreductase. J Bacteriol. 1972;112:131-41 pubmed
    ..Induction of isomeroreductase was enhanced by including glucose in the medium. This effect was shown to be due in part to the lowering of the pH of the medium, which presumably made inducer entry more rapid. ..
  9. Baez M, Patin D, Calhoun D. Deletion mapping of the ilvGOEDAC genes of Escherichia coli K-12. Mol Gen Genet. 1979;169:289-97 pubmed
    ..The order of ilv genes in the phage, and hence the order in the host chromosome, was found to be ilvG-ilvO-ilvEDA-ilvC. Lysogens containing lambdadilv phage were constructed for dominance analysis of regulatory mutations in the ilvO ..
  10. Baylor N, Williams A, Cofie N. Molecular characterization of ilvC specialized transducing phages of Escherichia coli K-12. Mol Gen Genet. 1983;191:347-52 pubmed
    A series of lambda defective ilvC specialized transducing phage has been isolated which carry regions of isoleucine and valine structural and regulatory genes derived from the ilv cluster at minute 83 on the linkage map of the chromosome ..
  11. Wek R, Hatfield G. Transcriptional activation at adjacent operators in the divergent-overlapping ilvY and ilvC promoters of Escherichia coli. J Mol Biol. 1988;203:643-63 pubmed
    The ilvC gene encodes acetohydroxy acid isomeroreductase (EC, the second enzyme in the parallel isoleucine-valine biosynthetic pathway...
  12. Biel A, Umbarger H. Mutations in the ilvY gene of Escherichia coli K-12 that cause constitutive expression of ilvC. J Bacteriol. 1981;146:718-24 pubmed
    A derivative of Escherichia coli K-12 bearing an ilvC-lac fusion has been studied. beta-Galactosidase formation in this strain is under the control of the ilvC promoter and is therefore induced by the acetohydroxy acids...
  13. Yang C, Shapiro B, Hung S, Mjolsness E, Hatfield G. A mathematical model for the branched chain amino acid biosynthetic pathways of Escherichia coli K12. J Biol Chem. 2005;280:11224-32 pubmed
    ..This model simulates the results of experimental measurements. ..
  14. Pledger W, Umbarger H. Isoleucine and valine metabolism in Escherichia coli. XXI. Mutations affecting derepression and valine resistance. J Bacteriol. 1973;114:183-94 pubmed
    ..2.1.16, l-threonine hydro-lyase (deaminating) and loss of isomeroreductase activity. ..
  15. Bastian S, Liu X, Meyerowitz J, Snow C, Chen M, Arnold F. Engineered ketol-acid reductoisomerase and alcohol dehydrogenase enable anaerobic 2-methylpropan-1-ol production at theoretical yield in Escherichia coli. Metab Eng. 2011;13:345-52 pubmed publisher
    ..Our results show how engineering cofactor dependence can overcome a critical obstacle to next-generation biofuel commercialization...
  16. Wong S, Lonhienne T, Winzor D, Schenk G, Guddat L. Bacterial and plant ketol-acid reductoisomerases have different mechanisms of induced fit during the catalytic cycle. J Mol Biol. 2012;424:168-79 pubmed publisher
    ..Support is thereby provided for the idea that plant and bacterial KARIs have evolved different mechanisms of induced fit to prepare the active site for catalysis. ..
  17. Island M, Kadner R. Interplay between the membrane-associated UhpB and UhpC regulatory proteins. J Bacteriol. 1993;175:5028-34 pubmed
    ..The constitutive behavior of all but one of these uhpB alleles was dependent on the presence of active forms of both UhpA and UhpC, which suggests that UhpB and UhpC act jointly as a complex in the signaling process. ..
  18. Chunduru S, Mrachko G, Calvo K. Mechanism of ketol acid reductoisomerase--steady-state analysis and metal ion requirement. Biochemistry. 1989;28:486-93 pubmed
    ..In the forward reaction direction, the deuterium kinetic isotope effect on V/K is 1.07 when acetolactate is the substrate and 1.39 when 3-hydroxy-3-methyl-2-oxobutyrate is the substrate. ..