1887

Abstract

The operon of K12 comprises structural genes for the two enzymes, IMP dehydrogenase and GMP synthetase, required for the biosynthesis of GMP from IMP. The specific activities of these enzymes were measured in various purine auxotrophs. -and mutants (guanine-specific) were derepressed under conditions of growth limitation by guanine but were repressed by excess guanine. This suggests that formation of the enzymes is normally controlled by a guanine nucleotide. Derepression of the operon in purine-starved mutants depended on the type of mutant and on whether adenine or guanine was provided. A strain (adenine-specific) and strains with early blocks in purine biosynthesis ( and ) did not derepress. or strains [5′-phosphoribosyl-5-aminoimidazole (AIR)-accumulating] derepressed only 4-fold. The operon was repressed in strains [5′-phosphoribosyl-5-amino-4-imidazolecarboxamide (AICAR)-accumulating] grown with limiting guanine or hypoxanthine, but derepressed by growth with limiting adenine. Two mutants ( and ) which can neither synthesize AMP and GMP , nor interconvert them, were isolated. The specific activity of IMP dehydrogenase in one of these strains grown with different concentrations of guanine and adenine revealed that adenine induces the operon whereas guanine represses it. Intracellular purine nucleotide pools were measured in a mutant repressed (guanine-grown) and derepressed (adenine-grown) for IMP dehydrogenase. The guanylate pool was similar under the two growth conditions; however, the adenylate pool of the adenine-grown bacteria was two to three times greater than that of the guanine-grown cells. A dual mechanism for regulating expression of the operon, involving induction by AMP and repression by GMP, is proposed.

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1981-03-01
2021-07-27
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References

  1. Dalal F.R., Gots R.E., Gots J.S. 1966; Mechanism of adenine inhibition in adenine-sensitive mutants of Salmonella typhimurium . Journal of Bacteriology 91:507–513
    [Google Scholar]
  2. Davidson J.N. 1976 The Biochemistry of the Nucleic Acids, 8th edn.. London: Chapman & Hall.;
    [Google Scholar]
  3. Davis B.D., Mingioli E.S. 1950; Mutants of Escherichia coli requiring methionine or vitamin B12. Journal of Bacteriology 60:17–28
    [Google Scholar]
  4. Gilbert H.J., Lowe C.R., Drabble W.T. 1979; Inosine 5′-monophosphate dehydrogenase of Escherichia coli: purification by affinity chromatography, subunit structure and inhibition by guanosine 5′ monophosphate. Biochemical Journal 183:481–494
    [Google Scholar]
  5. Gots J.S., Gollub E.G. 1957; Sequential blockade in adenine biosynthesis by genetic loss of an apparent bifunctionaldeacylase. Proceedings of the National Academy of Sciences of the United States of America 43:826–834
    [Google Scholar]
  6. Hochstadt-Ozer J., Stadtman E.R. 1971a; The regulation of purine utilization in bacteria. I. Purification of adenine phosphoribosyltransferase from Escherichia coli K12 and control of activity by nucleotides. Journal of Biological Chemistry 246:5294–5303
    [Google Scholar]
  7. Hochstadt-Ozer J., Stadtman E.R. 1971b; The regulation of purine utilization in bacteria. II. Adenine phosphoribosyltransferase in isolated membrane preparations and its role in transport of adenine across the membrane. Journal of Biological Chemistry 246:5304–5311
    [Google Scholar]
  8. Jackman L.E., Hochstadt J. 1976; Regulation of purine utilization in bacteria. VI. Characterisation of hypoxanthine and guanine uptake into isolated membrane vesicles from Salmonella typhimurium . Journal of Bacteriology 126:312–326
    [Google Scholar]
  9. Kelln R.A., Kinahan J.J., Foltermann K.F., O’Donovan G.A. 1975; Pyrimidine biosynthetic enzymes of Salmonella typhimurium, repressed specifically by growth in the presence of cytidine. Journal of Bacteriology 124:764–774
    [Google Scholar]
  10. Knowles C.J. 1977; Microbial metabolic regulation by adenine nucleotide pool. Symposia of the Society for General Microbiology 27:241–283
    [Google Scholar]
  11. Kuramitsu H.K., Udaka S., Moyed H.S. 1964; Induction of inosine 5′ monophosphate dehydrogenase and xanthosine 5′-monophosphate aminase by ribosyl-4-amino-5-imidazolecarboxamide in purine-requiring mutants of Escherichia coli B. Journal of Biological Chemistry 239:3425–3430
    [Google Scholar]
  12. Lambden P.R. 1972 Gene-enzyme relationships in the purine pathway of Escherichia coli. Ph.D. thesis: University of Southamptom.;
    [Google Scholar]
  13. Lambden P.R., Drabble W.T. 1973; The gua operon of Escherichia coli K-12: evidence for polarity from guaB to guaA . Journal of Bacteriology 115:992–1002
    [Google Scholar]
  14. Levitzki A. 1978 Quantitative Aspects of Allosteric Mechanisms. Berlin: Springer-Verlag.;
    [Google Scholar]
  15. Luria S.E. 1960 In The Bacteria 1 pp. 18–19 Edited by Gunsalus I. C., Stanier R. Y. New York: Academic Press.;
    [Google Scholar]
  16. Mager J., Magasanik B. 1960; Guanosine 5′-monophosphate reductase and its role in the interconversion of purine nucleotides. Journal of Biological Chemistry 235:1474–1478
    [Google Scholar]
  17. Mosteller R.E., Goldstein R.V. 1975; Unusual sensitivity of Escherichia coli to adenine or adenine plus histidine. Journal of Bacteriology 123:750–751
    [Google Scholar]
  18. Nazar R.N., Lawford H.G., Wong J.T. 1970; An improved procedure for extraction and analysis of cellular nucleotides. Analytical Biochemistry 35:305–313
    [Google Scholar]
  19. Neuhard J., Munch-Peterson A. 1966; The acid-soluble nucleotide pool in thymine-requiring mutants of Escherichia coli during thymine starvation. II. Changes in the amounts of deoxycytidine triphosphate and deoxyadenosine triphosphate in Escherichia coli 15 TAU . Biochimica et biophysica acta 114:61–71
    [Google Scholar]
  20. Nierlich D.P., Magasanik B. 1971; Control by feedback repression of the enzymes of purine biosynthesis in Aerobacter aerogenes . Biochemica et biophysica acta 230:349–361
    [Google Scholar]
  21. Nijkamp H.J.J. 1969; Regulatory role of adenine nucleotides in the biosynthesis of guanosine 5′-monophosphate. Journal of Bacteriology 100:585–593
    [Google Scholar]
  22. Nijkamp H.J.J., Dehaan P.G. 1967; Genetic and biochemical studies of the guanosine 5′-mono-phosphate pathway in Escherichia coli . Biochimica et biophysica acta 145:31–40
    [Google Scholar]
  23. Spencer M.E., Guest J.R. 1973; Isolation and properties of fumaratereductase mutants of Escherichia coli . Journal of Bacteriology 114:563–570
    [Google Scholar]
  24. Watson M.D. 1977 The biochemical genetics of purine nucleotide synthesis in Escherichia coli. Ph.D.thesis: University of Southampton.;
    [Google Scholar]
  25. Watson M.D., Drabble W.T. 1975; Relationship between purine nucleotide biosynthesis and requirement for thiamine in Escherichia coli K12. Proceedings of the Society for General Microbiology 2:44–45
    [Google Scholar]
  26. Wyngaarden J.B., Greenland R.A. 1963; The inhibition of succinyladenylatekinosynthetase of Escherichia coli by adenosine and guanosine 5′-monophosphates. Journal of Biological Chemistry 238:1054–1057
    [Google Scholar]
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