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. 1996 Feb;178(4):985–993. doi: 10.1128/jb.178.4.985-993.1996

Control of hemA expression in Rhodobacter sphaeroides 2.4.1: regulation through alterations in the cellular redox state.

J H Zeilstra-Ryalls 1, S Kaplan 1
PMCID: PMC177757  PMID: 8576072

Abstract

Rhodobacter sphaeroides 2.4.1 has the ability to synthesize a variety of tetrapyrroles, reflecting the metabolic versatility of this organism and making it capable of aerobic, anaerobic, photosynthetic, and diazotrophic growth. The hemA and hemT genes encode isozymes that catalyze the formation of 5-aminolevulinic acid, the first step in the biosynthesis of all tetrapyrroles present in R. sphaeroides 2.4.1. As part of our studies of the regulation and expression of these genes, we developed a genetic selection that uses transposon mutagenesis to identify loci affecting the aerobic expression of the hemA gene. In developing this selection, we found that sequences constituting an open reading frame immediately upstream of hemA positively affect hemA transcription. Using a transposon-based selection for increased hemA expression in the absence of the upstream open reading frame, we isolated three independent mutants. We have determined that the transposon insertions in these strains map to three different loci located on chromosome 1. One of the transposition sites mapped in the vicinity of the recently identified R. sphaeroides 2.4.1 homolog of the anaerobic regulatory gene fnr. By marker rescue and DNA sequence analysis, we found that the transposition site was located between the first two genes of the cco operon in R. sphaeroides 2.4.1, which encodes a cytochrome c terminal oxidase. Examination of the phenotype of the mutant strain revealed that, in addition to increased aerobic expression of hemA, the transposition event also conferred an oxygen-insensitive development of the photosynthetic membranes. We propose that the insertion of the transposon in cells grown in the presence of high oxygen levels has led to the generation of a cellular redox state resembling either reduced oxygen or anaerobiosis, thereby resulting in increased expression of hemA, as well as the accumulation of spectral complex formation. Several models are presented to explain these findings.

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Selected References

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  1. Allen L. N., Hanson R. S. Construction of broad-host-range cosmid cloning vectors: identification of genes necessary for growth of Methylobacterium organophilum on methanol. J Bacteriol. 1985 Mar;161(3):955–962. doi: 10.1128/jb.161.3.955-962.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Choudhary M., Mackenzie C., Nereng K. S., Sodergren E., Weinstock G. M., Kaplan S. Multiple chromosomes in bacteria: structure and function of chromosome II of Rhodobacter sphaeroides 2.4.1T. J Bacteriol. 1994 Dec;176(24):7694–7702. doi: 10.1128/jb.176.24.7694-7702.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Davis J., Donohue T. J., Kaplan S. Construction, characterization, and complementation of a Puf- mutant of Rhodobacter sphaeroides. J Bacteriol. 1988 Jan;170(1):320–329. doi: 10.1128/jb.170.1.320-329.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Donohue T. J., McEwan A. G., Kaplan S. Cloning, DNA sequence, and expression of the Rhodobacter sphaeroides cytochrome c2 gene. J Bacteriol. 1986 Nov;168(2):962–972. doi: 10.1128/jb.168.2.962-972.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dryden S. C., Kaplan S. Identification of cis-acting regulatory regions upstream of the rRNA operons of Rhodobacter sphaeroides. J Bacteriol. 1993 Oct;175(20):6392–6402. doi: 10.1128/jb.175.20.6392-6402.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dryden S. C., Kaplan S. Localization and structural analysis of the ribosomal RNA operons of Rhodobacter sphaeroides. Nucleic Acids Res. 1990 Dec 25;18(24):7267–7277. doi: 10.1093/nar/18.24.7267. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Eraso J. M., Kaplan S. Oxygen-insensitive synthesis of the photosynthetic membranes of Rhodobacter sphaeroides: a mutant histidine kinase. J Bacteriol. 1995 May;177(10):2695–2706. doi: 10.1128/jb.177.10.2695-2706.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Eraso J. M., Kaplan S. prrA, a putative response regulator involved in oxygen regulation of photosynthesis gene expression in Rhodobacter sphaeroides. J Bacteriol. 1994 Jan;176(1):32–43. doi: 10.1128/jb.176.1.32-43.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Fanica-Gaignier M., Clement-Metral J. D. ATP inhibition of aminolevulinate (ALA) synthetase activity in Rhodopseudomonas spheroides Y. Biochem Biophys Res Commun. 1971 Jul 2;44(1):192–198. doi: 10.1016/s0006-291x(71)80177-8. [DOI] [PubMed] [Google Scholar]
  10. García-Horsman J. A., Barquera B., Rumbley J., Ma J., Gennis R. B. The superfamily of heme-copper respiratory oxidases. J Bacteriol. 1994 Sep;176(18):5587–5600. doi: 10.1128/jb.176.18.5587-5600.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. García-Horsman J. A., Berry E., Shapleigh J. P., Alben J. O., Gennis R. B. A novel cytochrome c oxidase from Rhodobacter sphaeroides that lacks CuA. Biochemistry. 1994 Mar 15;33(10):3113–3119. doi: 10.1021/bi00176a046. [DOI] [PubMed] [Google Scholar]
  12. Gomelsky M., Kaplan S. appA, a novel gene encoding a trans-acting factor involved in the regulation of photosynthesis gene expression in Rhodobacter sphaeroides 2.4.1. J Bacteriol. 1995 Aug;177(16):4609–4618. doi: 10.1128/jb.177.16.4609-4618.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Gray K. A., Grooms M., Myllykallio H., Moomaw C., Slaughter C., Daldal F. Rhodobacter capsulatus contains a novel cb-type cytochrome c oxidase without a CuA center. Biochemistry. 1994 Mar 15;33(10):3120–3127. doi: 10.1021/bi00176a047. [DOI] [PubMed] [Google Scholar]
  14. Guerry P., van Embden J., Falkow S. Molecular nature of two nonconjugative plasmids carrying drug resistance genes. J Bacteriol. 1974 Feb;117(2):619–630. doi: 10.1128/jb.117.2.619-630.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Kahn D., David M., Domergue O., Daveran M. L., Ghai J., Hirsch P. R., Batut J. Rhizobium meliloti fixGHI sequence predicts involvement of a specific cation pump in symbiotic nitrogen fixation. J Bacteriol. 1989 Feb;171(2):929–939. doi: 10.1128/jb.171.2.929-939.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Keen N. T., Tamaki S., Kobayashi D., Trollinger D. Improved broad-host-range plasmids for DNA cloning in gram-negative bacteria. Gene. 1988 Oct 15;70(1):191–197. doi: 10.1016/0378-1119(88)90117-5. [DOI] [PubMed] [Google Scholar]
  17. Khoroshilova N., Beinert H., Kiley P. J. Association of a polynuclear iron-sulfur center with a mutant FNR protein enhances DNA binding. Proc Natl Acad Sci U S A. 1995 Mar 28;92(7):2499–2503. doi: 10.1073/pnas.92.7.2499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Lazazzera B. A., Bates D. M., Kiley P. J. The activity of the Escherichia coli transcription factor FNR is regulated by a change in oligomeric state. Genes Dev. 1993 Oct;7(10):1993–2005. doi: 10.1101/gad.7.10.1993. [DOI] [PubMed] [Google Scholar]
  19. Lee J. K., Kaplan S. cis-acting regulatory elements involved in oxygen and light control of puc operon transcription in Rhodobacter sphaeroides. J Bacteriol. 1992 Feb;174(4):1146–1157. doi: 10.1128/jb.174.4.1146-1157.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Lin E. C., Iuchi S. Regulation of gene expression in fermentative and respiratory systems in Escherichia coli and related bacteria. Annu Rev Genet. 1991;25:361–387. doi: 10.1146/annurev.ge.25.120191.002045. [DOI] [PubMed] [Google Scholar]
  21. Meinhardt S. W., Kiley P. J., Kaplan S., Crofts A. R., Harayama S. Characterization of light-harvesting mutants of Rhodopseudomonas sphaeroides. I. Measurement of the efficiency of energy transfer from light-harvesting complexes to the reaction center. Arch Biochem Biophys. 1985 Jan;236(1):130–139. doi: 10.1016/0003-9861(85)90612-5. [DOI] [PubMed] [Google Scholar]
  22. Michalski W. P., Nicholas D. J. Inhibition of bacteriochlorophyll synthesis in Rhodobacter sphaeroides subsp. denitrificans grown in light under denitrifying conditions. J Bacteriol. 1987 Oct;169(10):4651–4659. doi: 10.1128/jb.169.10.4651-4659.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Neidle E. L., Kaplan S. Expression of the Rhodobacter sphaeroides hemA and hemT genes, encoding two 5-aminolevulinic acid synthase isozymes. J Bacteriol. 1993 Apr;175(8):2292–2303. doi: 10.1128/jb.175.8.2292-2303.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sabaty M., Kaplan S. mgpS, a complex regulatory locus involved in the transcriptional control of the puc and puf operons in Rhodobacter sphaeroides 2.4.1. J Bacteriol. 1996 Jan;178(1):35–45. doi: 10.1128/jb.178.1.35-45.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Schlüter A., Rüberg S., Krämer M., Weidner S., Priefer U. B. A homolog of the Rhizobium meliloti nitrogen fixation gene fixN is involved in the production of a microaerobically induced oxidase activity in the phytopathogenic bacterium Agrobacterium tumefaciens. Mol Gen Genet. 1995 Apr 20;247(2):206–215. doi: 10.1007/BF00705651. [DOI] [PubMed] [Google Scholar]
  26. Suwanto A., Kaplan S. Physical and genetic mapping of the Rhodobacter sphaeroides 2.4.1 genome: genome size, fragment identification, and gene localization. J Bacteriol. 1989 Nov;171(11):5840–5849. doi: 10.1128/jb.171.11.5840-5849.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Tai T. N., Havelka W. A., Kaplan S. A broad-host-range vector system for cloning and translational lacZ fusion analysis. Plasmid. 1988 May;19(3):175–188. doi: 10.1016/0147-619x(88)90037-6. [DOI] [PubMed] [Google Scholar]
  28. Thöny-Meyer L., Beck C., Preisig O., Hennecke H. The ccoNOQP gene cluster codes for a cb-type cytochrome oxidase that functions in aerobic respiration of Rhodobacter capsulatus. Mol Microbiol. 1994 Nov;14(4):705–716. doi: 10.1111/j.1365-2958.1994.tb01308.x. [DOI] [PubMed] [Google Scholar]
  29. Varga A. R., Kaplan S. Synthesis and stability of reaction center polypeptides and implications for reaction center assembly in Rhodobacter sphaeroides. J Biol Chem. 1993 Sep 15;268(26):19842–19850. [PubMed] [Google Scholar]
  30. Wraight C. A., Lueking D. R., Fraley R. T., Kaplan S. Synthesis of photopigments and electron transport components in synchronous phototrophic cultures of Rhodopseudomonas sphaeroides. J Biol Chem. 1978 Jan 25;253(2):465–471. [PubMed] [Google Scholar]
  31. Zeilstra-Ryalls J. H., Kaplan S. Aerobic and anaerobic regulation in Rhodobacter sphaeroides 2.4.1: the role of the fnrL gene. J Bacteriol. 1995 Nov;177(22):6422–6431. doi: 10.1128/jb.177.22.6422-6431.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Zeilstra-Ryalls J. H., Kaplan S. Regulation of 5-aminolevulinic acid synthesis in Rhodobacter sphaeroides 2.4.1: the genetic basis of mutant H-5 auxotrophy. J Bacteriol. 1995 May;177(10):2760–2768. doi: 10.1128/jb.177.10.2760-2768.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]

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