Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1992 Jun;174(12):3884–3888. doi: 10.1128/jb.174.12.3884-3888.1992

Regulation of nitrogenase-2 in Azotobacter vinelandii by ammonium, molybdenum, and vanadium.

S Jacobitz 1, P E Bishop 1
PMCID: PMC206095  PMID: 1597411

Abstract

Under diazotrophic conditions in the absence of molybdenum and in the presence of vanadium, Azotobacter vinelandii reduces N2 to NH4+ by using nitrogenase-2, a V-containing enzyme complex encoded by vnfH (the gene for dinitrogenase reductase-2), and vnfDGK (the genes for dinitrogenase-2 subunits). Accumulation of the vnfHorfFd and vnfDGK transcripts occurred under Mo-deficient conditions in the presence and absence of V; however, in the case of vnfDGK, the protein products only accumulated in the presence of V. This suggests that V is required for translation of the vnfDGK transcripts. In addition, expression of vnfH-lacZ and vnfD-lacZ transcriptional fusions was only partially repressed in the presence of NH4+. Transcripts hybridizing with vnfH (1.4 and 1.0 kb), vnfDG (3.4 and 1.8 kb), and vnfK (3.4 kb) were detected in RNA extracted from wild-type cells cultured with NH4+ in the presence or absence of V. However, nitrogenase-2 subunits were not detected in extracts of cells derepressed for nitrogenase-2 in the presence of NH4+. These results indicate that this nitrogen source acts at the posttranscriptional level as well as at the transcriptional level. vnf transcripts were not detected in the presence of Mo (with or without NH4+).

Full text

PDF
3886

Images in this article

3886Image
on p.3886

Selected References

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

  1. Bishop P. E., Hawkins M. E., Eady R. R. Nitrogen fixation in molybdenum-deficient continuous culture by a strain of Azotobacter vinelandii carrying a deletion of the structural genes for nitrogenase (nifHDK). Biochem J. 1986 Sep 1;238(2):437–442. doi: 10.1042/bj2380437. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bishop P. E., Jarlenski D. M., Hetherington D. R. Evidence for an alternative nitrogen fixation system in Azotobacter vinelandii. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7342–7346. doi: 10.1073/pnas.77.12.7342. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bishop P. E., Jarlenski D. M., Hetherington D. R. Expression of an alternative nitrogen fixation system in Azotobacter vinelandii. J Bacteriol. 1982 Jun;150(3):1244–1251. doi: 10.1128/jb.150.3.1244-1251.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chisnell J. R., Premakumar R., Bishop P. E. Purification of a second alternative nitrogenase from a nifHDK deletion strain of Azotobacter vinelandii. J Bacteriol. 1988 Jan;170(1):27–33. doi: 10.1128/jb.170.1.27-33.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Collins J. J., Roberts G. P., Brill W. J. Posttranscriptional control of Klebsiella pneumoniae nif mRNA stability by the nifL product. J Bacteriol. 1986 Oct;168(1):173–178. doi: 10.1128/jb.168.1.173-178.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Contreras A., Drummond M., Bali A., Blanco G., Garcia E., Bush G., Kennedy C., Merrick M. The product of the nitrogen fixation regulatory gene nfrX of Azotobacter vinelandii is functionally and structurally homologous to the uridylyltransferase encoded by glnD in enteric bacteria. J Bacteriol. 1991 Dec;173(24):7741–7749. doi: 10.1128/jb.173.24.7741-7749.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. DE WITT C. W., ROWE J. A. N,O-Diacetylneuraminic acid and N-acetylneuraminic acid in Escherichia coli. Nature. 1959 Aug 1;184(Suppl 6):381–382. doi: 10.1038/184381b0. [DOI] [PubMed] [Google Scholar]
  8. Drummond M. H., Contreras A., Mitchenall L. A. The function of isolated domains and chimaeric proteins constructed from the transcriptional activators NifA and NtrC of Klebsiella pneumoniae. Mol Microbiol. 1990 Jan;4(1):29–37. doi: 10.1111/j.1365-2958.1990.tb02012.x. [DOI] [PubMed] [Google Scholar]
  9. Jacobson M. R., Premakumar R., Bishop P. E. Transcriptional regulation of nitrogen fixation by molybdenum in Azotobacter vinelandii. J Bacteriol. 1986 Aug;167(2):480–486. doi: 10.1128/jb.167.2.480-486.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Joerger R. D., Bishop P. E. Nucleotide sequence and genetic analysis of the nifB-nifQ region from Azotobacter vinelandii. J Bacteriol. 1988 Apr;170(4):1475–1487. doi: 10.1128/jb.170.4.1475-1487.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Joerger R. D., Jacobson M. R., Bishop P. E. Two nifA-like genes required for expression of alternative nitrogenases by Azotobacter vinelandii. J Bacteriol. 1989 Jun;171(6):3258–3267. doi: 10.1128/jb.171.6.3258-3267.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Joerger R. D., Jacobson M. R., Premakumar R., Wolfinger E. D., Bishop P. E. Nucleotide sequence and mutational analysis of the structural genes (anfHDGK) for the second alternative nitrogenase from Azotobacter vinelandii. J Bacteriol. 1989 Feb;171(2):1075–1086. doi: 10.1128/jb.171.2.1075-1086.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Joerger R. D., Loveless T. M., Pau R. N., Mitchenall L. A., Simon B. H., Bishop P. E. Nucleotide sequences and mutational analysis of the structural genes for nitrogenase 2 of Azotobacter vinelandii. J Bacteriol. 1990 Jun;172(6):3400–3408. doi: 10.1128/jb.172.6.3400-3408.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Joerger R. D., Premakumar R., Bishop P. E. Tn5-induced mutants of Azotobacter vinelandii affected in nitrogen fixation under Mo-deficient and Mo-sufficient conditions. J Bacteriol. 1986 Nov;168(2):673–682. doi: 10.1128/jb.168.2.673-682.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Joerger R. D., Wolfinger E. D., Bishop P. E. The gene encoding dinitrogenase reductase 2 is required for expression of the second alternative nitrogenase from Azotobacter vinelandii. J Bacteriol. 1991 Jul;173(14):4440–4446. doi: 10.1128/jb.173.14.4440-4446.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Krol A. J., Hontelez J. G., Roozendaal B., van Kammen A. On the operon structure of the nitrogenase genes of Rhizobium leguminosarum and Azotobacter vinelandii. Nucleic Acids Res. 1982 Jul 24;10(14):4147–4157. doi: 10.1093/nar/10.14.4147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Messing J., Gronenborn B., Müller-Hill B., Hans Hopschneider P. Filamentous coliphage M13 as a cloning vehicle: insertion of a HindII fragment of the lac regulatory region in M13 replicative form in vitro. Proc Natl Acad Sci U S A. 1977 Sep;74(9):3642–3646. doi: 10.1073/pnas.74.9.3642. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. O'Farrell P. H. High resolution two-dimensional electrophoresis of proteins. J Biol Chem. 1975 May 25;250(10):4007–4021. [PMC free article] [PubMed] [Google Scholar]
  19. Page W. J., von Tigerstrom M. Optimal conditions for transformation of Azotobacter vinelandii. J Bacteriol. 1979 Sep;139(3):1058–1061. doi: 10.1128/jb.139.3.1058-1061.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Santero E., Toukdarian A., Humphrey R., Kennedy C. Identification and characterization of two nitrogen fixation regulatory regions, nifA and nfrX, in Azotobacter vinelandii and Azotobacter chroococcum. Mol Microbiol. 1988 May;2(3):303–314. doi: 10.1111/j.1365-2958.1988.tb00033.x. [DOI] [PubMed] [Google Scholar]
  21. Simon R., Quandt J., Klipp W. New derivatives of transposon Tn5 suitable for mobilization of replicons, generation of operon fusions and induction of genes in gram-negative bacteria. Gene. 1989 Aug 1;80(1):161–169. doi: 10.1016/0378-1119(89)90262-x. [DOI] [PubMed] [Google Scholar]
  22. Strandberg G. W., Wilson P. W. Formation of the nitrogen-fixing enzyme system in Azotobacter vinelandii. Can J Microbiol. 1968 Jan;14(1):25–31. doi: 10.1139/m68-005. [DOI] [PubMed] [Google Scholar]
  23. Wolfinger E. D., Bishop P. E. Nucleotide sequence and mutational analysis of the vnfENX region of Azotobacter vinelandii. J Bacteriol. 1991 Dec;173(23):7565–7572. doi: 10.1128/jb.173.23.7565-7572.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES