Skip to main content
NCBI home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1980 Oct;77(10):5817–5821. doi: 10.1073/pnas.77.10.5817

Regulation of Rhizobium nitrogen fixation by the unadenylylated glutamine synthetase I system

Robert A Ludwig 1,*
PMCID: PMC350162  PMID: 16592892

Abstract

Rhizobium sp. 32H1 glutamine auxotrophs have a complex phenotype: a highly adenylylated glutamine synthetase [GS; L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] I and an undetectable GS II (GS II-). They are defective in the adenylylation cascade system for GS I. Prototrophic revertants are of two classes: those (3204 type) which retain the adenylylated GS I phenotype but become GS II+, and those (3205 type) which acquire a constitutive unadenylylated GS I but remain GS II-. Like the parent auxotroph, 3204 remains incapable of nitrogen fixation both in culture and in root nodules of Macroptileum atropurpureum. In contrast, 3205 is nitrogenase constitutive. This implies that GS I or associated adenylylation proteins are involved in the control of Rhizobium 32H1 nif gene expression and that GS II is not so involved. Normally, rhizobia fix atmospheric N2 only during symbiosis and, in so doing, only transiently synthesize nitrogenase. Moreover, whereas wild-type strains export ammonium, constitutive strains can assimilate ammonium produced by nitrogenase. This phenotype allows direct selection of nitrogen fixation-defective mutants in Rhizobium.

Keywords: control of gene expression, covalent enzyme modification, legume root nodules

Full text

PDF
5817

Images in this article

5819Image
on p.5819

Selected References

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

  1. Bender R. A., Magasanik B. Autogenous regulation of the synthesis of glutamine synthetase in Klebsiella aerogenes. J Bacteriol. 1977 Oct;132(1):106–112. doi: 10.1128/jb.132.1.106-112.1977. [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 F. J., Turner G. L. Activity of nitrogenase and glutamine synthetase in relation to availability of oxygen in continuous cultures of a strain of cowpea Rhizobium sp. supplied with excess ammonium. Biochim Biophys Acta. 1978 Feb 1;538(3):406–416. doi: 10.1016/0304-4165(78)90402-6. [DOI] [PubMed] [Google Scholar]
  4. 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]
  5. Foor F., Reuveny Z., Magasanik B. Regulation of the synthesis of glutamine synthetase by the PII protein in Klebsiella aerogenes. Proc Natl Acad Sci U S A. 1980 May;77(5):2636–2640. doi: 10.1073/pnas.77.5.2636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Gaillardin C. M., Magasanik B. Involvement of the product of the glnF gene in the autogenous regulation of glutamine synthetase formation in Klebsiella aerogenes. J Bacteriol. 1978 Mar;133(3):1329–1338. doi: 10.1128/jb.133.3.1329-1338.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Garcia E., Bancroft S., Rhee S. G., Kustu S. The product of a newly identified gene, gInF, is required for synthesis of glutamine synthetase in Salmonella. Proc Natl Acad Sci U S A. 1977 Apr;74(4):1662–1666. doi: 10.1073/pnas.74.4.1662. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Keister D. L. Acetylene reduction by pure cultures of Rhizobia. J Bacteriol. 1975 Sep;123(3):1265–1268. doi: 10.1128/jb.123.3.1265-1268.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Ljones T., Burris R. H. ATP hydrolysis and electron transfer in the nitrogenase reaction with different combinations of the iron protein and the molybdenum-iron protein. Biochim Biophys Acta. 1972 Jul 12;275(1):93–101. doi: 10.1016/0005-2728(72)90027-8. [DOI] [PubMed] [Google Scholar]
  10. Ludwig R. A. Control of ammonium assimilation in Rhizobium 32H1. J Bacteriol. 1978 Jul;135(1):114–123. doi: 10.1128/jb.135.1.114-123.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Ludwig R. A. Physiological roles of glutamine synthetases I and II in ammonium assimilation in Rhizobium sp. 32H1. J Bacteriol. 1980 Mar;141(3):1209–1216. doi: 10.1128/jb.141.3.1209-1216.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. 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]
  13. Moore J. V., Dixon B. Metastasis of a transplantable mammary tumour in rats treated with cyclophosphamide and/or irradiation. Br J Cancer. 1977 Aug;36(2):221–226. doi: 10.1038/bjc.1977.181. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Pahel G., Tyler B. A new glnA-linked regulatory gene for glutamine synthetase in Escherichia coli. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4544–4548. doi: 10.1073/pnas.76.9.4544. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Streicher S. L., Shanmugam K. T., Ausubel F., Morandi C., Goldberg R. B. Regulation of nitrogen fixation in Klebsiella pneumoniae: evidence for a role of glutamine synthetase as a regulator of nitrogenase synthesis. J Bacteriol. 1974 Nov;120(2):815–821. doi: 10.1128/jb.120.2.815-821.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Tyler B., Deleo A. B., Magasanik B. Activation of transcription of hut DNA by glutamine synthetase. Proc Natl Acad Sci U S A. 1974 Jan;71(1):225–229. doi: 10.1073/pnas.71.1.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Wittenberg J. B. Facilitated oxygen diffusion. The role of leghemoglobin in nitrogen fixation by bacteroids isolated from soybean root nodules. J Biol Chem. 1974 Jul 10;249(13):4057–4066. [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES