Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1978 Jul;135(1):114–123. doi: 10.1128/jb.135.1.114-123.1978

Control of ammonium assimilation in Rhizobium 32H1.

R A Ludwig
PMCID: PMC224783  PMID: 27498

Abstract

The symbiotic, nitrogen-fixing bacterium Rhizobium sp. 32H1 is a specialized ammonium producer during symbiosis. However, during free-living growth, Rhizobium 32H1 assimilates ammonium very poorly. Two pathways of ammonium assimilation exist in enteric bacteria. One is mediated by glutamate dehydrogenase, and the other is mediated by glutamine synthetase-glutamate synthase. The former pathway is altogether inoperative in Rhizobium 32H1; the latter pathway operates at a slow rate and is under strict negative control by ammonium itself. Rhizobium 32H1 glutamine synthetase activity is modulated by both repression-derepression and reversible adenylylation. For a biochemical process lacking an alternative pathway, such a regulatory pattern exacerbates the very process. This suggests that Rhizobium 32H1 restricts its own ammonium assimilation to maximize the contribution of fixed nitrogen to the host plant during symbiosis.

Full text

PDF
114

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bender R. A., Janssen K. A., Resnick A. D., Blumenberg M., Foor F., Magasanik B. Biochemical parameters of glutamine synthetase from Klebsiella aerogenes. J Bacteriol. 1977 Feb;129(2):1001–1009. doi: 10.1128/jb.129.2.1001-1009.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bender R. A., Magasanik B. Regulatory mutations in the Klebsiella aerogenes structural gene for glutamine synthetase. J Bacteriol. 1977 Oct;132(1):100–105. doi: 10.1128/jb.132.1.100-105.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bergersen J. F., Turner G. L. Nitrogen fixation by the bacteroid fraction of breis of soybean root nodules. Biochim Biophys Acta. 1967 Aug 29;141(3):507–515. doi: 10.1016/0304-4165(67)90179-1. [DOI] [PubMed] [Google Scholar]
  4. Brenchley J. E., Prival M. J., Magasanik B. Regulation of the synthesis of enzymes responsible for glutamate formation in Klebsiella aerogenes. J Biol Chem. 1973 Sep 10;248(17):6122–6128. [PubMed] [Google Scholar]
  5. Brown C. M., Dilworth M. J. Ammonia assimilation by rhizobium cultures and bacteroids. J Gen Microbiol. 1975 Jan;86(1):39–48. doi: 10.1099/00221287-86-1-39. [DOI] [PubMed] [Google Scholar]
  6. Darrow R. A., Knotts R. R. Two forms of glutamine synthetase in free-living root-nodule bacteria. Biochem Biophys Res Commun. 1977 Sep 23;78(2):554–559. doi: 10.1016/0006-291x(77)90214-5. [DOI] [PubMed] [Google Scholar]
  7. Friedrich B., Magasanik B. Urease of Klebsiella aerogenes: control of its synthesis by glutamine synthetase. J Bacteriol. 1977 Aug;131(2):446–452. doi: 10.1128/jb.131.2.446-452.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. KAPLAN N. O. Symposium on multiple forms of enzymes and control mechanisms. I. Multiple forms of enzymes. Bacteriol Rev. 1963 Jun;27:155–169. doi: 10.1128/br.27.2.155-169.1963. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Kingdon H. S., Shapiro B. M., Stadtman E. R. Regulation of glutamine synthetase. 8. ATP: glutamine synthetase adenylyltransferase, an enzyme that catalyzes alterations in the regulatory properties of glutamine synthetase. Proc Natl Acad Sci U S A. 1967 Oct;58(4):1703–1710. doi: 10.1073/pnas.58.4.1703. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  11. Ludwig R. A., Signer E. R. Glutamine synthetase and control of nitrogen fixation in Rhizobium. Nature. 1977 May 19;267(5608):245–248. doi: 10.1038/267245a0. [DOI] [PubMed] [Google Scholar]
  12. Meers J. L., Tempest D. W., Brown C. M. 'Glutamine(amide):2-oxoglutarate amino transferase oxido-reductase (NADP); an enzyme involved in the synthesis of glutamate by some bacteria. J Gen Microbiol. 1970 Dec;64(2):187–194. doi: 10.1099/00221287-64-2-187. [DOI] [PubMed] [Google Scholar]
  13. Miller R. E., Stadtman E. R. Glutamate synthase from Escherichia coli. An iron-sulfide flavoprotein. J Biol Chem. 1972 Nov 25;247(22):7407–7419. [PubMed] [Google Scholar]
  14. Roon R. J., Even H. L., Larimore F. Glutamate synthase: properties of the reduced nicotinamide adenine dinucleotide-dependent enzyme from Saccharomyces cerevisiae. J Bacteriol. 1974 Apr;118(1):89–95. doi: 10.1128/jb.118.1.89-95.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Shapiro B. M., Ginsburg A. Effects of specific divalent cations on some physical and chemical properties of glutamine synthetase from Escherichia coli. Taut and relaxed enzyme forms. Biochemistry. 1968 Jun;7(6):2153–2167. doi: 10.1021/bi00846a018. [DOI] [PubMed] [Google Scholar]
  16. Shapiro B. M., Stadtman E. R. 5'-adenylyl-O-tyrosine. The novel phosphodiester residue of adenylylated glutamine synthetase from Escherichia coli. J Biol Chem. 1968 Jul 10;243(13):3769–3771. [PubMed] [Google Scholar]
  17. Shapiro B. M., Stadtman E. R. The regulation of glutamine synthesis in microorganisms. Annu Rev Microbiol. 1970;24:501–524. doi: 10.1146/annurev.mi.24.100170.002441. [DOI] [PubMed] [Google Scholar]
  18. Tronick S. R., Ciardi J. E., Stadtman E. R. Comparative biochemical and immunological studies of bacterial glutamine synthetases. J Bacteriol. 1973 Sep;115(3):858–868. doi: 10.1128/jb.115.3.858-868.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES