1887

Abstract

Ribonucleotide reductases (RNRs) are a family of complex enzymes that play an essential role in all organisms because they catalyse synthesis of deoxyribonucleotides required for DNA replication and repair. Three different classes of RNR have been described according to their metal cofactors and organic radicals. Class Ib RNR is encoded in four different genes (, , and ) organized in an operon. The authors previously cloned and sequenced the genes encoding the active class Ib RNR of and showed that these genes are clustered in an atypical region, which differs from that of other known class Ib enzymes because of an intergenic sequence (1171 bp) present between and . This study investigated the transcriptional organization and regulation of this region by RT-PCR. Three different and independent mRNA were found (, and an ORF present in the intergenic region), each one being transcribed from its own promoter and being essential for normal growth. The ratio of to mRNA was 9·1, as determined by competitive RT-PCR; the expression of both and was found to be dependent on the culture growth phase, and was induced in the presence of hydroxyurea, manganese and hydrogen peroxide. This is believed to be the first direct evidence for a manganese-dependent transcriptional regulation of genes. These results suggest a common and coordinated regulation of the different genes, despite their being transcribed from independent promoters.

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2003-04-01
2019-10-17
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References

  1. Björklund, S., Skog, S., Tribukait, B. & Thelander, L. ( 1990; ). S-phase-specific expression of mammalian ribonucleotide reductase R1 and R2 subunit mRNAs. Biochemistry 29, 5452–5458.[CrossRef]
    [Google Scholar]
  2. Breidbach, T., Krauth-Siegelb, R. L. & Steverdinga, D. ( 2000; ). Ribonucleotide reductase is regulated via the R2 subunit during the life cycle of Trypanosoma brucei. FEBS Lett 273, 212–216.
    [Google Scholar]
  3. Fieschi, F., Torrents, E., Toulokhonova, L., Jordan, A., Hellman, U., Barbe, J., Gibert, I., Karsson, M. & Sjöberg, B. M. ( 1998; ). The manganese-containing ribonucleotide reductase of Corynebacterium ammoniagenes is a class Ib enzyme. J Biol Chem 273, 4329–4337.[CrossRef]
    [Google Scholar]
  4. Filpula, D. & Fuchs, J. A. ( 1978; ). Regulation of the synthesis of ribonucleoside diphosphate reductase in Escherichia coli: specific activity of the enzyme in relationship to perturbations of DNA replication. J Bacteriol 135, 429–435.
    [Google Scholar]
  5. Guittet, O., Hakansson, P., Voevodskaya, N., Fridd, S., Graslund, A., Arakawa, H., Nakamura, Y. & Thelander, L. ( 2001; ). Mammalian p53R2 protein forms an active ribonucleotide reductase in vitro with the R1 protein, which is expressed both in resting cells in response to DNA damage and in proliferating cells. J Biol Chem 276, 40647–40651.[CrossRef]
    [Google Scholar]
  6. Jacobson, B. A. &, Fuchs. J. A. ( 1998; ). A 45 bp inverted repeat is required for cell cycle regulation of the Escherichia coli nrd operon. Mol Microbiol 28, 1307–1314.[CrossRef]
    [Google Scholar]
  7. Jakubovics, N. S. & Jenkinson, H. F. ( 2001; ). Out of the iron age: new insights into the critical role of manganese homeostasis in bacteria. Microbiology 147, 1709–1718.
    [Google Scholar]
  8. Jordan, A & Reichard, P. ( 1998; ). Ribonucleotide reductases. Annu Rev Biochem 67, 71–98.[CrossRef]
    [Google Scholar]
  9. Jordan, A., Aragall, E., Gibert, I. & Barbe, J. ( 1996a; ). Promoter identification and expression analysis of Salmonella typhimurium and Escherichia coli nrdEF operons encoding one of two class I ribonucleotide reductases present in both bacteria. Mol Microbiol 19, 777–790.[CrossRef]
    [Google Scholar]
  10. Jordan, A., Pontis, E., Åslund, F., Hellman, U., Gibert, I. & Reichard, P. ( 1996b; ). The ribonucleotide reductase system of Lactococcus lactis: characterization of an NrdEF system and a new electron transport protein. J Biol Chem 271, 8779–8785.[CrossRef]
    [Google Scholar]
  11. Jordan, A., Torrents, E., Sala, I., Hellman, U., Gibert, I. & Reichard, P. ( 1999; ). Ribonucleotide reduction in Pseudomonas species: simultaneous presence of active enzymes from different classes. J Bacteriol 181, 3974–3980.
    [Google Scholar]
  12. Hanke, H. ( 2001; ). Iron and metal regulation in bacteria. Curr Opin Microbiol 4, 172–177.[CrossRef]
    [Google Scholar]
  13. Huque, Y., Fieschi, F., Torrents, E., Gibert, I., Eliasson, R., Reichard, P., Sahlin, M. & Sjöberg, B. M. ( 2000; ). The active form of the R2F protein of class Ib ribonucleotide reductase from Corynebacterium ammoniagenes is a diferric protein. J Biol Chem 275, 25365–25371.[CrossRef]
    [Google Scholar]
  14. Lee, J. H., Wang, T., Ault, K., Liu, J., Schmitt, P. & Holmes, R. K. ( 1997; ). Identification and characterization of three new promoter/operators from Corynebacterium diphtheriae that are regulated by the diphtheria toxin repressor (DtxR) and iron. Infect Immun 65, 4273–4280.
    [Google Scholar]
  15. Masalha, M., Borovok, I., Schreiber, R., Aharonowitz, Y. & Cohen, G. ( 2001; ). Analysis of transcription of the Staphylococcus aureus aerobic class Ib and anaerobic class III ribonucleotide reductase genes in response to oxygen. J Bacteriol 183, 7260–7272.[CrossRef]
    [Google Scholar]
  16. Miller, J. M. ( 1972; ). Experiments in Molecular Genetics. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  17. Monje-Casas, F., Jurado, F., Prieto-Álamo, M. J., Holmgren, A. & Pueyo, C. ( 2001; ). Expression analysis of the nrdHIEF operon from Escherichia coli. J Biol Chem 276, 18031–18037.[CrossRef]
    [Google Scholar]
  18. Oka, T., Udagawa, K. & Kinoshita, S. ( 1968; ). Unbalanced growth death due to depletion of Mn2+ in Brevibacterium ammoniagenes. J Bacteriol 96, 1760–1767.
    [Google Scholar]
  19. Posey, J. E., Hardham, J. M., Norris, S. J. & Gherardini, F. C. ( 1999; ). Chararactization of a manganese-dependent regulatory protein, TroR, from Treponema pallidum. Proc Natl Acad Sci U S A 96, 10887–10892.[CrossRef]
    [Google Scholar]
  20. Rigali, S., Derouaux, A., Giannotta, F. & Dusart, J. ( 2002; ). Subdivision of the helix-turn-helix GntR family of bacterial regulators in the FadR, HutC, MocR, and YtrA subfamilies. J Biol Chem 277, 12507–12515.[CrossRef]
    [Google Scholar]
  21. Sambrook, J., Fritsch, E. F. & Maniatis, T. ( 1989; ). Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory.
  22. Schäfer, A., Tauch, A., Jäger, W., Kalinowski, J., Thierbach, G. & Pühler, A. ( 1994; ). Small mobilizable multi-purpose cloning vectors derived from the Escherichia coli pK18 and pK19: selection of defined deletion in the chromosome of Corynebacterium glutamicum. Gene 145, 69–73.[CrossRef]
    [Google Scholar]
  23. Schimpff-Weiland, G., Follmann, H. & Auling, G. ( 1981; ). A new manganese-activated ribonucleotide reductase found in gram-positive bacteria. Biochem Biophys Res Commun 102, 1276–1282.[CrossRef]
    [Google Scholar]
  24. Schmitt, M. P. ( 1997; ). Transcription of the Corynebacterium diphtheriae hmuO gene is regulated by iron and heme. Infect Immun 65, 4634–4641.
    [Google Scholar]
  25. Schwarzer, A. & Pühler, A. ( 1991; ). Manipulation of Corynebacterium glutamicum by gene disruption and replacement. Bio/Technology 9, 84–87.[CrossRef]
    [Google Scholar]
  26. Stubbe, J. & van der Donk, W. ( 1995; ). Ribonucleotide reductases: radical enzymes with suicidal tendencies. Chem Biol 2, 793–801.[CrossRef]
    [Google Scholar]
  27. Torrents, E., Buist, G., Liu, A., Eliasson, R., Kok, J., Gibert, I., Graslund, A. & Reichard, P. ( 2000a; ). The anaerobic (class III) ribonucleotide reductase from Lactococcus lactis. Catalytic properties and allosteric regulation of the pure enzyme system. J Biol Chem 275, 2463–2471.[CrossRef]
    [Google Scholar]
  28. Torrents, E., Jordan, A., Karlsson, M. & Gibert, I. ( 2000b; ). Occurrence of multiple ribonucleotide reductase classes in γ-proteobacteria species. Curr Microbiol 41, 346–351.[CrossRef]
    [Google Scholar]
  29. Willing, A., Follmann, H. & Auling, G. ( 1998; ). Ribonucleotide reductase of Brevibacterium ammoniagenes is a manganese enzyme. Eur J Biochem 170, 603–611.
    [Google Scholar]
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