Abstract
A number of in-frame deletions have been constructed in the Klebsiella pneumoniae regulatory gene nifL. The effects of each nifL mutation on NifA-mediated expression from the nifH promoter of K. pneumoniae have then been assessed with respect to both nitrogen and oxygen control. These experiments indicate that, in contrast to the situation with the homologous regulatory proteins NtrB and NtrC, NifA activity is not impaired in the absence of NifL. We conclude that the only function of NifL is to inactivate NifA in response to an increase in the nitrogen or oxygen status of the cell.
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References
Austin S, Henderson N, Dixon R (1987) Requirements for transcriptional activation in vitro of the nitrogen regulated glnA and nifLA promoters from Klebsiella pneumoniae: dependence on activator concentration. Mol Microbiol 1:92–100
Bergersen FJ, Kennedy C, Hill S (1982) Influence of low oxygen concentration on derepression of nitrogenase in Klebsiella pneumoniae. J Gen Microbiol 128:909–915
Buchanan-Wollaston V, Cannon MC, Beynon J, Cannon FC (1981) The role of the nifA gene product in the transcriptional regulation of nif (nitrogen fixation) expression in Klebsiella pneumoniae. Nature 294:776–778
Dimri GP, Das HK (1988) Transcriptional regulation of nitrogen fixation genes by DNA supercoiling. Mol Gen Genet 212:360–363
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
Drummond M, Wootton J (1987) Sequence of nifL from Klebsiella pneumoniae: mode of action and relationship to two families of regulatory proteins. Mol Microbiol 1:37–44
Drummond M, Whitty P, Wootton J (1986) Sequence and domain relationships of ntrC and nifA from Klebsiella pneumoniae: homologies to other regulatory proteins. EMBO J 5:441–447
Espin G, Alvarez-Morales A, Cannon F, Dixon R, Merrick M (1982) Cloning of the glnA, ntrB and ntrC genes of Klebsiella pneumoniae. 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 191:485–491
Hill S, Kennedy K, Kavanagh E, Goldberg RB, Hanau R (1981) Nitrogen fixation gene (nifL) involved in oxygen regulation of nitrogenase synthesis in K. pneumoniae. Nature 290:424–426
MacFarlane SA, Merrick MJ (1987) Analysis of the Klebsiella pneumoniae ntrB gene by site-directed in vitro mutagenesis. Mol Microbiol 1:133–142
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
Merrick M (1988) Regulation of nitrogen assimilation by bacteria In: Cole JA, Ferguson S (eds) The nitrogen and sulphur cycles. Society for General Microbiology Symposium 42, Cambridge University Press, Cambridge, pp 331–361
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
Ninfa AJ, Magasanik B (1986) Covalent modification of the glnG product NRI by the glnL product NRII regulates transcription of the glnALG operon in Escherichia coli. Proc Natl Acad Sci USA 83:5909–5913
Reidel GE, Brown SE, Ausubel FM (1983) Nitrogen fixation by Klebsiella pneumoniae is inhibited by certain multicopy hybrid nif plasmids. J. Bacteriol 153:45–56
Sibold L, Elmerich C (1982) Constitutive expression of nitrogen fixation (nif) genes of Klebsiella pneumoniae due to a DNA duplication. EMBO J 1:1551–1558
Sibold L, Melck D, Elmerich C (1981) A nif mutant of Klebsiella pneumoniae fixing nitrogen in the presence of ammonia. FEMS Microbiol Letts 10:37–41
Stoker NG, Fairweather NF, Spratt BG (1982) Versatile low-copynumber plasmid vectors for cloning in Escherichia coli. Gene 18:335–341
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Arnott, M., Sidoti, C., Hill, S. et al. Deletion analysis of the nitrogen fixation regulatory gene, nifL of Klebsiella pneumoniae . Arch. Microbiol. 151, 180–182 (1989). https://doi.org/10.1007/BF00414436
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DOI: https://doi.org/10.1007/BF00414436