Gene Symbol: leuB
Description: 3-isopropylmalate dehydrogenase, NAD(+)-dependent
Alias: ECK0075, JW5807
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Wallon G, Kryger G, Lovett S, Oshima T, Ringe D, Petsko G. Crystal structures of Escherichia coli and Salmonella typhimurium 3-isopropylmalate dehydrogenase and comparison with their thermophilic counterpart from Thermus thermophilus. J Mol Biol. 1997;266:1016-31 pubmed publisher
    ..The mutation in the hydrophobic core of T. thermophilus IPMDH resulted in a cavity of 32 A3, but no significant effect on the activity and thermostability of the mutant was observed...
  2. Kirino H, Aoki M, Aoshima M, Hayashi Y, Ohba M, Yamagishi A, et al. Hydrophobic interaction at the subunit interface contributes to the thermostability of 3-isopropylmalate dehydrogenase from an extreme thermophile, Thermus thermophilus. Eur J Biochem. 1994;220:275-81 pubmed
    We cloned and sequenced the leuB gene encoding 3-isopropylmalate dehydrogenase from Escherichia coli K-12 (JM103). Errors (33 residues) were found and corrected in the sequence previously reported for the leuB gene of Thermus thermophilus...
  3. Gráczer E, Varga A, Melnik B, Semisotnov G, Zavodszky P, Vas M. Symmetrical refolding of protein domains and subunits: example of the dimeric two-domain 3-isopropylmalate dehydrogenases. Biochemistry. 2009;48:1123-34 pubmed publisher
    ..The high similarity of time courses (both in biphasicity and in their rates) strongly suggests cooperative folding of the domains during formation of the native three-dimensional structure of IPMDH. ..
  4. Magyar C, Szilagyi A, Zavodszky P. Relationship between thermal stability and 3-D structure in a homology model of 3-isopropylmalate dehydrogenase from Escherichia coli. Protein Eng. 1996;9:663-70 pubmed
    ..The comparison proved that most of the structural features underlying the stability differences between the two enzymes were predicted correctly. ..
  5. Gráczer E, Varga A, Hajdú I, Melnik B, Szilagyi A, Semisotnov G, et al. Rates of unfolding, rather than refolding, determine thermal stabilities of thermophilic, mesophilic, and psychrotrophic 3-isopropylmalate dehydrogenases. Biochemistry. 2007;46:11536-49 pubmed
    ..On the basis of our observations, folding rates appear to be dictated by global structural characteristics (such as native topology, i.e., contact order) rather than by thermodynamic stability. ..
  6. Wright B, Minnick M. Reversion rates in a leuB auxotroph of Escherichia coli K-12 correlate with ppGpp levels during exponential growth. Microbiology. 1997;143 ( Pt 3):847-54 pubmed
    ..as two spoT transductants of the relA- strain, were examined with respect to ppGpp levels and reversion rates of a leuB- allele under nine different conditions...
  7. 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. ..
  8. Reimers J, Schmidt K, Longacre A, Reschke D, Wright B. Increased transcription rates correlate with increased reversion rates in leuB and argH Escherichia coli auxotrophs. Microbiology. 2004;150:1457-66 pubmed
    Escherichia coli auxotrophs of leuB and argH were examined to determine if higher rates of transcription in derepressed genes were correlated with increased reversion rates...
  9. Lunzer M, Golding G, Dean A. Pervasive cryptic epistasis in molecular evolution. PLoS Genet. 2010;6:e1001162 pubmed publisher
    ..This demonstrates that epistatic interactions can occur between distant (>20Å) sites. Phylogenetic analysis shows that incompatible mutations were fixed in different lineages. ..

More Information


  1. Davis M, Calvo J. Isolation and characterization of lambda pleu bacteriophages. J Bacteriol. 1977;129:1078-90 pubmed
    ..One type (e.g., lambda pleu9) transduces leuD, leuC, and leuB strains to prototrophy. The other type (e.g., lambda pleu 13) transduces leuA strains to prototrophy...
  2. Hajdú I, Szilagyi A, Kardos J, Zavodszky P. A link between hinge-bending domain motions and the temperature dependence of catalysis in 3-isopropylmalate dehydrogenase. Biophys J. 2009;96:5003-12 pubmed publisher
  3. Wright B, Longacre A, Reimers J. Hypermutation in derepressed operons of Escherichia coli K12. Proc Natl Acad Sci U S A. 1999;96:5089-94 pubmed
    ..A quantitative correlation was established between leuB mRNA abundance and leuB- reversion rates...
  4. Wallon G, Yamamoto K, Kirino H, Yamagishi A, Lovett S, Petsko G, et al. Purification, catalytic properties and thermostability of 3-isopropylmalate dehydrogenase from Escherichia coli. Biochim Biophys Acta. 1997;1337:105-12 pubmed
    ..At 40 degrees C the K(m) of E. coli IPMDH was 105 microM for IPM and 321 microM for NAD, the kcat was 69 s-1. The half denaturation temperature was 64 degrees C, which was 20 degrees C lower than that of the thermophile enzyme. ..
  5. Wright B. The effect of the stringent response on mutation rates in Escherichia coli K-12. Mol Microbiol. 1996;19:213-9 pubmed
    ..Reversion rates of leuB- and argH- were significantly higher in the relA+ than in the relA- strain, and the reversion rates in both strains ..
  6. Hare R, Walker S, Dorman T, Greene J, Guzman L, Kenney T, et al. Genetic footprinting in bacteria. J Bacteriol. 2001;183:1694-706 pubmed
    ..In addition, the ability of recombinant proteins to complement mutagenized hosts has been evaluated by genetic footprinting using a bacteriophage lambda transposon delivery system. ..
  7. Yang H, Kessler D. Genetic analysis of the leucine region in Escherichia coli B-r: gene-enzyme assignments. J Bacteriol. 1974;117:63-72 pubmed
    ..These studies have identified four genes in the leucine region having the same order as found in Salmonella typhimurium: ara... leuDCBA. ..
  8. Somers J, Amzallag A, Middleton R. Genetic fine structure of the leucine operon of Escherichia coli K-12. J Bacteriol. 1973;113:1268-72 pubmed
    ..1.1). It is concluded that the gross structure of the leucine operon in E. coli is closely similar to, if not identical with, the gross structure of the leucine operon in Salmonella typhimurium. ..