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.

Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.26133-0
2003-04-01
2020-09-21
Loading full text...

Full text loading...

/deliver/fulltext/micro/149/4/mic1491011.html?itemId=/content/journal/micro/10.1099/mic.0.26133-0&mimeType=html&fmt=ahah

References

  1. Björklund S., Skog S., Tribukait B., Thelander L.. 1990; S-phase-specific expression of mammalian ribonucleotide reductase R1 and R2 subunit mRNAs. Biochemistry29:5452–5458
    [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 Lett273:212–216
    [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 Chem273:4329–4337
    [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 Bacteriol135:429–435
    [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 Chem276:40647–40651
    [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 Microbiol28:1307–1314
    [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. Microbiology147:1709–1718
    [Google Scholar]
  8. Jordan A., Reichard P.. 1998; Ribonucleotide reductases. Annu Rev Biochem67:71–98
    [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 Microbiol19:777–790
    [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 Chem271:8779–8785
    [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 Bacteriol181:3974–3980
    [Google Scholar]
  12. Hanke H.. 2001; Iron and metal regulation in bacteria. Curr Opin Microbiol4:172–177
    [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 Chem275:25365–25371
    [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 Immun65:4273–4280
    [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 Bacteriol183:7260–7272
    [Google Scholar]
  16. Miller J. M.. 1972; Experiments in Molecular Genetics Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  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 Chem276:18031–18037
    [Google Scholar]
  18. Oka T., Udagawa K., Kinoshita S.. 1968; Unbalanced growth death due to depletion of Mn2+ in Brevibacterium ammoniagenes . J Bacteriol96:1760–1767
    [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 A96:10887–10892
    [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 Chem277:12507–12515
    [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;
    [Google Scholar]
  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 . Gene145:69–73
    [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 Commun102:1276–1282
    [Google Scholar]
  24. Schmitt M. P.. 1997; Transcription of the Corynebacterium diphtheriae hmuO gene is regulated by iron and heme. Infect Immun65:4634–4641
    [Google Scholar]
  25. Schwarzer A., Pühler A.. 1991; Manipulation of Corynebacterium glutamicum by gene disruption and replacement. Bio/Technology9:84–87
    [Google Scholar]
  26. Stubbe J., van der Donk W.. 1995; Ribonucleotide reductases: radical enzymes with suicidal tendencies. Chem Biol2:793–801
    [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 Chem275:2463–2471
    [Google Scholar]
  28. Torrents E., Jordan A., Karlsson M., Gibert I.. 2000b; Occurrence of multiple ribonucleotide reductase classes in γ -proteobacteria species. Curr Microbiol41:346–351
    [Google Scholar]
  29. Willing A., Follmann H., Auling G.. 1998; Ribonucleotide reductase of Brevibacterium ammoniagenes is a manganese enzyme. Eur J Biochem170:603–611
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.26133-0
Loading
/content/journal/micro/10.1099/mic.0.26133-0
Loading

Data & Media loading...

Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error