1887

Abstract

SUMMARY: A pyrimidine-requiring mutant of Neurospora was found to grow on minimal medium when the proportion of CO in the gas-phase (air) was increased to 30% (v/v); arginine prevented growth in 30% CO, but did not prevent growth when pyrimidines were present. An arginine-requiring mutant also grew on minimal medium in the presence of 30% CO. The response of this mutant to CO was annulled by pyrimidines. It is proposed that these mutants have defects in carbamoyl phosphate synthesis. Wild-type Neurospora may have two pathways for making carbamoyl phosphate from CO, one pathway subject to feed-back inhibition or repression by arginine, the other pathway subject to feed-back inhibition or repression by pyrimidines. The pyrimidine mutant may lack an enzyme which produces carbamoyl phosphate for pyrimidine synthesis, and the arginine mutant may lack an enzyme which produces carbamoyl phosphate for arginine synthesis. Thus each mutant may have only one effective mechanism for carbamoyl phosphate synthesis. It is suggested that 30% CO causes increased synthesis of carbamoyl phosphate by the remaining pathway in each mutant, thereby providing sufficient carbamoyl phosphate to overcome the nutritional deficiency. The inhibition of the pyrimidine mutant by arginine, and the inhibition of the arginine mutant by pyrimidines, are explained as feed-back inhibition or repression of the remaining pathway for carbamoyl phosphate synthesis.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-34-1-131
1964-01-01
2024-03-28
Loading full text...

Full text loading...

/deliver/fulltext/micro/34/1/mic-34-1-131.html?itemId=/content/journal/micro/10.1099/00221287-34-1-131&mimeType=html&fmt=ahah

References

  1. Borek E., Waelsch H. 1951; The effect of temperature on the nutritional requirement of micro-organisms. J. biol. Chem 190:191
    [Google Scholar]
  2. Charles H. P. 1962; Response of Neurospora mutants to carbon dioxide. Nature, Lond 195:359
    [Google Scholar]
  3. Davis R. H. 1960; An enzymatic difference among pyr-3 mutants of Neurospor acrassa . Proc. nat. Acad. Sci., Wash 46:677
    [Google Scholar]
  4. Davis R. H. 1961; Suppressor of pyrimidine-8 mutants of Neurospora and its relation to arginine synthesis. Science 134:470
    [Google Scholar]
  5. Davis R. H. 1962; Consequences of a suppressor gene effective with pyrimidine and proline mutants of Neurospora. Genetics 47:351
    [Google Scholar]
  6. Davis R. H., Woodward V. W. 1962; The relationship between gene suppression and aspartate transcarbamylase activity in pyr-3 mutants of Neurospora. Genetics 47:1075
    [Google Scholar]
  7. Doudney C. O., Wagner R. P. 1952; Threonine inhibition in a strain of Neurospora. Proc. not. Acad. Sci., Wash 38:196
    [Google Scholar]
  8. Fairley J. L. 1954; The growth-promoting effect of certain amino acids for pyrimidinelessNeurospora mutants. J. biol. Chem 210:347
    [Google Scholar]
  9. Haldane J. B. S. 1954 The Biochemistry of Genetics London: George Allen and Unwin;
    [Google Scholar]
  10. Houlahan M. B., Mitchell H. K. 1947; A suppressor in Neurospora and its use as evidence for allelism. Proc. not. Acad. Sci., Wash 33:223
    [Google Scholar]
  11. Houlahan M. B., Mitchell H. K. 1948; Evidence for an interrelation in the metabolism of lysine, arginine and pyrimidines in Neurospora. Proc. not. Acad. Sci., Wash 34:465
    [Google Scholar]
  12. Jones M. E., Spector L., Lipmann F. 1955; Carbamyl phosphate, the carbamyl donor in enzymatic citrulline synthesis. J. Amer. Chem. Soc 77:819
    [Google Scholar]
  13. Markert C. L., ller F. 1959; Multiple forms of enzymes: tissue, ontogenetic and species specific patterns. Proc. nat. Acad. Sci., Wash 45:753
    [Google Scholar]
  14. Miller E. J., Harrison J. S. 1950; Growth inhibition of a yeast by uracil, and its reversal by arginine. Nature, Lond 166:1035
    [Google Scholar]
  15. Mitchell M. B., Mitchell H. K. 1952; Observations on the behaviour of suppressors in Neurospora. Proc. nat. Acad. Sci., Wash 38:205
    [Google Scholar]
  16. Pontecorvo G. 1949; Auxanographic techniques in biochemical genetics. J. gen. Microbiol 3:122
    [Google Scholar]
  17. Reissig J. L. 1960; Forward and back mutation in the pyr-3 region of Neurospora. I. Mutations from arginine dependence to prototrophy. Genet. Res 1:356
    [Google Scholar]
  18. Ryan F. J., Beadle G. W., Tatum E. L. 1943; The tube method of measuring the growth rate of Neurospora. Amer. J. Bot 30:784
    [Google Scholar]
  19. Stadtman E. R., Cohen G. N., Lebras G., Szulmajster H. 1961; Feed-back inhibition and repression of aspartokinase activity in Escherichia coli and Saccharomyces cerevisiae . J. biol. Chem 236:2033
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-34-1-131
Loading
/content/journal/micro/10.1099/00221287-34-1-131
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error