1887

Abstract

possesses 2-oxoacid dehydrogenase (EC 1.2.4.4) similar to that found in mammalian cells. The activity is readily detected in cells which have been cultured in a minimal medium containing a branched-chain amino acid. Mutants defective in lipoamide dehydrogenase also lack 2-oxoacid dehydrogenase and are thus unable to catabolize branched-chain amino acids: 2-oxoacids accumulate in the cultures of these cells. The 2-oxoacid dehydrogenase activity is distinct from both 2-oxoglutarate dehydrogenase and pyruvate dehydrogenase, because it could not be detected in assay conditions which permitted the measurement of 2-oxoglutarate dehydrogenase and vice versa. In addition, a strain lacking 2-oxoglutarate dehydrogenase (::) retained 2-oxoacid dehydrogenase as did a mutant specifically lacking pyruvate dehydrogenase (::Tn). In complex media the specific activity of this enzyme is highest in YEP (yeast extract-peptone)-glycerol and lowest in YEP-acetate and YEP-fructose. 2-Oxoacid dehydrogenase could not be detected in cells which had been transferred to sporulation medium. These results suggest that in the catabolism of branched-chain amino acids occurs via 2-oxoacid dehydrogenase, not via the ‘Ehrlich Pathway’.

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1992-10-01
2024-10-03
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References

  1. Cooper T. G. 1982 Nitrogen metabolism in Saccharomyces cerevisiae . In The Molecular Biology of the Yeast Saccharomyces cerevisiae. Metabolism and Gene Expression, pp. 211–287 Edited by Strathern J. N., , Jones E. W., & person-group-type="editor"> Broach J. R. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  2. Dawes I. W. 1989; Complex regulation of gene expression in Saccharomyces cerevisiae and the implications for biotechnology. Australian Journal of Biotechnology 3:117–124
    [Google Scholar]
  3. Dickinson J. R., & Williams A. S. 1986; A genetic and biochemical analysis of the role of gluconeogenesis in sporulation of Saccharo-myces cerevisiae . Journal of General Microbiology 132:2605–2610
    [Google Scholar]
  4. Dickinson J. R., , Ambler R. P., & Dawes I. W. 1985; Abnormal amino acid metabolism in mutants of Saccharomyces cerevisiae affected in initiation of sporulation. European Journal of Biochemistry 148:405–406
    [Google Scholar]
  5. Dickinson J. R., , Roy D. J., & Dawes I. W. 1986; A mutation affecting lipoamide dehydrogenase, pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase activities in Saccharomyces cerevisiae . Molecular and General Genetics 204:103–107
    [Google Scholar]
  6. Ehrlich F. 1904; Über das natiirliche Isomere des Leucins. Berichte der Deutschen Chemischen Gesellschaft 37:1809–1840
    [Google Scholar]
  7. Fast D. 1973; Sporulation synchrony in yeast. Journal of Bacteriology 116:200–210
    [Google Scholar]
  8. Kikuchi G. 1973; Glycine cleavage system. Composition, reaction mechanism, and physiological significance. Molecular and Cellular Biochemistry l:169–187
    [Google Scholar]
  9. Lowe P. N., , Hogdson J. A., & Perham R. N. 1983; Dual role of a single multienzyme complex in the oxidative decarboxylation of pyruvate and branched-chain 2-oxo acids in Bacillus subtilis . Biochemical Journal 215:133–140
    [Google Scholar]
  10. Neubauer O., & Fromherz K. 1911; Über den Abbau der Aminosauren bei der Hefegarung. Hoppe-Seyler's Zeitschrift filr Physiologische Chemie 70:326–350
    [Google Scholar]
  11. Ogur M., , Liu T. N., , Cheung I., , Paulavicius I., , Wales W., , Mehnert D., & Blaise D. 1977; 'Active' one-carbon-generation in Saccharomyces cerevisiae . Journal of Bacteriology 129:926–933
    [Google Scholar]
  12. Repetto B., & Tzagoloff A. 1989; Structure and regulation of KGDl, the structural gene for yeast α-Ketoglutarate dehydrogenase. Molecular and Cellular Biology 9:2695–2705
    [Google Scholar]
  13. Ross J., , Reid G. A., & Dawes I. W. 1988; The nucleotide sequence of the LPDJ gene encoding lipoamide dehydrogenase in Saccharo-myces cerevisiae: comparison between eukaryotic and prokaryotic sequences for related enzymes and identification of potential upstream control sites. Journal of General Microbiology 134:1131–1139
    [Google Scholar]
  14. Roy D. J., & Dawes I. W. 1987; Cloning and characterization of the gene encoding lipoamide dehydrogenase in Saccharomyces cerevisiae . Journal of General Microbiology 133:925–933
    [Google Scholar]
  15. Sentheshanmuganathan S. 1960; The mechanism of the formation of higher alcohols from amino acids by Saccharomyces cerevisiae . Biochemical Journal 14, 568–576
    [Google Scholar]
  16. Steensma H. Y., , Holterman L., , Dekker I., , Van Sluis C. A., & Wenzel T. J. 1990; Molecular cloning of the gene for the Ela subunit of the pyruvate dehydrogenase complex from Saccharomyces cerevisiae . European Journal of Biochemistry 191:769–774
    [Google Scholar]
  17. Sykes P. J, , Burns G., , Menard J., , Hatter K., & Sokatch J. R. 1987; Molecular cloning of genes encoding branched-chain keto acid dehydrogenase of Pseudomonas putida . Journal of Bacteriology 169:1619–1625
    [Google Scholar]
  18. Woodward J. R., & Cirillo V. P. 1977; Amino add transport in nitrogen-starved cells of Saccharomyces cerevisiae . Journal of Bacteriology 130:714–723
    [Google Scholar]
  19. Yeaman S. J. 1986; The mammalian 2-oxoacid dehydrogenases: a complex family. Trends in Biochemical Sciences 11:293–296
    [Google Scholar]
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