Summary
A comprehensive study of nif expression in Klebsiella pneumoniae at the level of transcription, translation and nitrogenase activity during derepression and repression by NH +4 and O2 revealed that (1) transcription and translation rates remained coupled under all conditions; (2) these rates reached a peak during derepression and then decreased to a low level; (3) the transcription profile of nifLA had two peaks; the first was at 1 h before and the second coincided with that of the other operons; and (4) the peaks of nif transcription coincided with a trough in the profile of stringent regulation of RNA synthesis. Our results provide strong evidence that nif-specific repression by NH +4 and O2 occurs exclusively by transcription inhibition and that repression by O2 is independent of transcriptional regulation of the nifLA operon. We have also found evidence which together with the results of previous work shows that O2 repression of nifA mediated transcription involves the nifL gene product.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ausubel FM, Cannon FC (1981) Molecular genetic analysis of Klebsiella pneumoniae nitrogen fixation (nif) genes. Cold Spring Harbor Sym Quant Biol 45:487–499
Beynon J, Cannon M, Buchanan-Wollaston V, Cannon F (1983) The nif promoters of Klebsiella pneumoniae have a characteristic primary structure. Cell 34:665–671
Buchanan-Wollaston V, Cannon MC, Beynon JL, Cannon FC (1981a) The use of cloned nif (nitrogen fixation) DNA to investigate transcriptional regulation of nif expression in Klebsiella pneumoniae. Mol Gen Genet 184:102–106
Buchanan-Wollaston V, Cannon MC, Beynon JL, Cannon FC (1981b) Role of the nifA gene product in the regulation of nif expression in Klebsiella pneumoniae. Nature 294:776–778
Cannon FC (1980) Genetic studies with diazotrophs. In: Bergerson FJ (ed) Methods for evaluating biological nitrogen fixation. Wiley, Chichester, pp 367–413
Chaney AL, Marbach EP (1962) Modified reagents for determination of urea and ammonia. Clin Chem 8:130–132
Dixon R, Eady RR, Espin G, Hill S, Iaccarino M, Kahn D, Merrick M (1980) Analysis of regulation of Klebsiella pneumoniae nitrogen fixation (nif) gene cluster with gene fusions. Nature 286:128–132
Dixon R, Kennedy C, Merrick M (1981) Genetic control of nitrogen fixation. In: Genetics as a tool in microbiology, Society for General Microbiology symposium 31. Cambridge University Press, Cambridge, pp 161–185
Drummond M, Clements J, Merrick M, Dixon R (1983) Positive control and autogenous regulation of the nifLA promoter in Klebsiella pneumoniae. Nature 301:302–307
Eady RR, Issack R, Kennedy C, Postgate JR, Ratcliffe H (1978) Nitrogenase synthesis in Klebsiella pneumoniae: comparison of ammonium and oxygen regulation. J Gen Microbiol 104:277–285
Espin G, Alvarez-Morales A, Cannon F, Dixon R, Merrick M (1982) Cloning of the glnA, ntrB and ntrC genes of Klebsiella pneumoniae and studies of their role in regulation of the nitrogen fixation (nif) gene cluster. Mol Gen Genet 186:518–524
Filser M, Merrick M, Cannon F (1983) Cloning and characterisation of nifLA regulatory mutations from Klebsiella pneumoniae. Mol Gen Genet 191:435–491
Hill S (1976) The apparent ATP requirement for nitrogen fixation in growing Klebsiella pneumoniae. J Gen Microbiol 95:297–312
Hill S, Kennedy C, Kavanaugh E, Goldberg RB, Hanau R (1981) Nitrogen fixation gene (nifL) involved in oxygen regulation of nitrogenase synthesis in Klebsiella pneumoniae. Nature 290:424–426
Kaluza K, Hennecke H (1981) Regulation of nitrogenase messenger RNA synthesis and stability in Klebsiella pneumoniae. Arch Microbiol 130:38–43
Kaluza K, Hennecke H (1982) The nitrogenase genes of Klebsiella pneumoniae are transcribed into a single polycistronic mRNA subsequent to nifLA expression. FEMS Microbiol Lett 15:57–60
Kennedy C, Cannon F, Cannon M, Dixon R, Hill S, Jensen J, Kumar S, McLean P, Merrick M, Robson R, Postgate J (1981) Recent advances in the genetics and regulation of nitrogen fixation. In: Gibson AH, Newton WE (eds) Current perspectives in nitrogen fixation. Australian Academy of Science, Canberra, pp 146–156
Lowe DJ, Thorneley RNF, Postgate JR (1984) The mechanism of substrate reduction by nitrogenase. In: Veeger C, Newton WE (eds) Advances in nitrogen fixation research. Martinus Nijhoff/Dr W Junk, The Hague, pp 133–138
MacNeil D, Brill WJ (1980) Mutations in nif genes that cause Klebsiella pneumoniae to be derepressed for nitrogenase synthesis in the presence of ammonium. J Bacteriol 144:744–751
MacNeil D, Zhu J, Brill WJ (1981) Regulation of nitrogen fixation in Klebsiella pneumoniae: isolation and characterization of strains with nif-lac fusions. J Bacteriol 145:348–357
MacNeil T, MacNeil D, Roberts GP, Supiano MA, Brill WJ (1978) Fine structure mapping and complementation analysis of nif (nitrogen fixation) genes in Klebsiella pneumoniae. J Bacteriol 136:253–266
Magasanik B (1982) Genetic control of nitrogen assimilation in bacteria. Annu Rev Genet 16:135–168
Merrick M (1983) Nitrogen control of the nif regulon in Klebsiella pneumoniae: involvement of the ntrA gene and analogies between ntrC and nifA. EMBO J 2:39–44
Merrick M, Filser M, Dixon R, Elmerich C, Sibold J, Houmard J (1980) Use of translocatable genetic elements to construct a fine-structure map of the Klebsiella pneumoniae nitrogen fixation (nif) gene cluster. J Gen Microbiol 117:509–520
Merrick M, Hill S, Hennecke H, Hahn M, Dixon R, Kennedy C (1982) Repressor properties of the nifL gene product in Klebsiella pneumoniae. Mol Gen Genet 185:75–81
Ow DW, Ausubel FM (1983) Regulation of nitrogen metabolism by nifA gene product in Klebsiella pneumoniae. Nature 301:307–313
Postgate JR, Cannon FC (1981) The molecular and genetic manipulation of nitrogen fixation genes. Phil Trans Royal Soc London B 292:589–599
Pühler A, Klipp W (1981) Fine-structure analysis of the gene region for N2-fixation (nif) of Klebsiella pneumoniae. In: Bothe H, Trebst A (eds) Biology of inorganic nitrogen and sulphur. Springer-Verlag, Berlin Heidelberg New York, pp 276–286
Riedel GE, Ausubel FM, Cannon FC (1979) Physical map of chromosomal nitrogen fixation (nif) genes of Klebsiella pneumoniae. Proc Natl Acad Sci USA 76:2866–2870
Riedel GE, Brown SE, Ausubel FM (1983) Nitrogen fixation in Klebsiella pneumoniae is inhibited by certain multicopy hybrid nif plasmids. J Bacteriol 153:45–56
Roberts GP, Brill WJ (1980) Gene-product relationships of the nif (nitrogen fixation) regulon of Klebsiella pneumoniae. J Bacteriol 144:210–216
Roberts GP, Brill WJ (1981) Genetics and regulation of nitrogen fixation. Annu Rev Microbiol 35:207–235
Roberts GP, MacNeil T, MacNeil D, Brill WJ (1978) Regulation and characterization of protein products coded by the nif (nitrogen fixation), genes of Klebsiella pneumoniae. J Bacteriol 136:267–279
Sibold L, Elmerich C (1982) Constitutive expression of nitrogen fixation (fix) genes of Klebsiella pneumoniae due to a DNA duplication. EMBO J 1:1551–1558
Southern E (1975) Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol 98:503–517
St John RT, Johnston HM, Seidman C, Garfinkel D, Gordon JK, Shah VK, Brill WJ (1975) Biochemistry and genetics of Klebsiella pneumoniae mutant strains unable to fix N2. J Bacteriol 121:759–765
Author information
Authors and Affiliations
Additional information
Communicated by G.R. Fink
Rights and permissions
About this article
Cite this article
Cannon, M., Hill, S., Kavanaugh, E. et al. A molecular genetic study of nif expression in Klebsiella pneumoniae at the level of transcription, translation and nitrogenase activity. Molec. Gen. Genet. 198, 198–206 (1985). https://doi.org/10.1007/BF00382996
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00382996