G Unden

Summary

Affiliation: University of Mainz
Country: Germany

Publications

  1. pmc Escherichia coli possesses two homologous anaerobic C4-dicarboxylate membrane transporters (DcuA and DcuB) distinct from the aerobic dicarboxylate transport system (Dct)
    S Six
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat, Mainz, Germany
    J Bacteriol 176:6470-8. 1994
  2. ncbi request reprint Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significance
    B Wackwitz
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Mol Gen Genet 262:876-83. 1999
  3. ncbi request reprint Alternative respiratory pathways of Escherichia coli: energetics and transcriptional regulation in response to electron acceptors
    G Unden
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Biochim Biophys Acta 1320:217-34. 1997
  4. ncbi request reprint The oxygen-responsive transcriptional regulator FNR of Escherichia coli: the search for signals and reactions
    G Unden
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    Mol Microbiol 25:205-10. 1997
  5. ncbi request reprint Transcriptional regulation of the proton translocating NADH dehydrogenase genes (nuoA-N) of Escherichia coli by electron acceptors, electron donors and gene regulators
    J Bongaerts
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Mol Microbiol 16:521-34. 1995
  6. ncbi request reprint Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications
    Q H Tran
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Eur J Biochem 244:155-60. 1997
  7. pmc Functioning of DcuC as the C4-dicarboxylate carrier during glucose fermentation by Escherichia coli
    E Zientz
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, 55099 Mainz, Germany
    J Bacteriol 181:3716-20. 1999
  8. ncbi request reprint Regulatory O2 tensions for the synthesis of fermentation products in Escherichia coli and relation to aerobic respiration
    S Becker
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    Arch Microbiol 168:290-6. 1997
  9. pmc Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system
    E Zientz
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, 55099 Mainz, Germany
    J Bacteriol 180:5421-5. 1998
  10. pmc O2 as the regulatory signal for FNR-dependent gene regulation in Escherichia coli
    S Becker
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    J Bacteriol 178:4515-21. 1996

Collaborators

Detail Information

Publications36

  1. pmc Escherichia coli possesses two homologous anaerobic C4-dicarboxylate membrane transporters (DcuA and DcuB) distinct from the aerobic dicarboxylate transport system (Dct)
    S Six
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat, Mainz, Germany
    J Bacteriol 176:6470-8. 1994
    ..The anaerobic dicarboxylate transport systems (Dcu) are genetically and functionally distinct from the aerobic system (Dct)...
  2. ncbi request reprint Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significance
    B Wackwitz
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Mol Gen Genet 262:876-83. 1999
    ..This ensures higher ATP yields under conditions where large amounts of ATP are required...
  3. ncbi request reprint Alternative respiratory pathways of Escherichia coli: energetics and transcriptional regulation in response to electron acceptors
    G Unden
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Biochim Biophys Acta 1320:217-34. 1997
    ..Reductive activation could be achieved by cellular reductants in the absence of O2. In addition, O2 may cause destruction and loss of the FeS cluster. It is not known whether this process is required for regulation of FNR function...
  4. ncbi request reprint The oxygen-responsive transcriptional regulator FNR of Escherichia coli: the search for signals and reactions
    G Unden
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    Mol Microbiol 25:205-10. 1997
    ..Only the terminal reductases of respiration, and not the dehydrogenases, are regulated in such a way as to achieve maximal H+/e- ratios and ATP yields...
  5. ncbi request reprint Transcriptional regulation of the proton translocating NADH dehydrogenase genes (nuoA-N) of Escherichia coli by electron acceptors, electron donors and gene regulators
    J Bongaerts
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Mol Microbiol 16:521-34. 1995
    ..A physiological role for the transcriptional stimulation by O2 and nitrate is suggested...
  6. ncbi request reprint Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications
    Q H Tran
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Eur J Biochem 244:155-60. 1997
    ..NADH-->dimethylsulfoxide respiration is also dependent on NADH dehydrogenase I. The consequences for energy conservation by anaerobic respiration with NADH as a donor are discussed...
  7. pmc Functioning of DcuC as the C4-dicarboxylate carrier during glucose fermentation by Escherichia coli
    E Zientz
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, 55099 Mainz, Germany
    J Bacteriol 181:3716-20. 1999
    ..Upon overexpression in a dcuC promoter mutant (dcuC*), DcuC was able to compensate for DcuA and DcuB in fumarate-succinate exchange and fumarate uptake...
  8. ncbi request reprint Regulatory O2 tensions for the synthesis of fermentation products in Escherichia coli and relation to aerobic respiration
    S Becker
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    Arch Microbiol 168:290-6. 1997
    ..Therefore, under microoxic conditions, the pO2 appears to be too high for (mixed acid) fermentation to function and too low for aerobic respiration by quinol oxidase bo...
  9. pmc Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system
    E Zientz
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, 55099 Mainz, Germany
    J Bacteriol 180:5421-5. 1998
    ..The CitAB two-component regulatory system, which is highly similar to DcuSR, had no effect on C4-dicarboxylate regulation of any of the genes...
  10. pmc O2 as the regulatory signal for FNR-dependent gene regulation in Escherichia coli
    S Becker
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    J Bacteriol 178:4515-21. 1996
    ..Non-redox-active, structural O2 analogs like CO, CN-, and N3-, could not mimic the effect of O2 on FNR-regulated genes under anaerobic conditions and did not decrease the inhibitory effect of O2 under aerobic conditions...
  11. ncbi request reprint C4-dicarboxylate carriers and sensors in bacteria
    I G Janausch
    Institut für Mikrobiologie und Weinforschung, Johann Gutenberg Universität Mainz, Germany
    Biochim Biophys Acta 1553:39-56. 2002
    ..In DcuS the periplasmic domain seems to be essential for direct interaction with the C4-dicarboxylates. In signal perception by DctB, interaction of the C4-dicarboxylates with DctB and the DctA carrier plays an important role...
  12. ncbi request reprint LrhA as a new transcriptional key regulator of flagella, motility and chemotaxis genes in Escherichia coli
    D Lehnen
    Institut fur Mikrobiologie and Weinforschung, Johannes Gutenberg Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    Mol Microbiol 45:521-32. 2002
    ..It is suggested that LrhA is a key regulator controlling the transcription of flagellar, motility and chemotaxis genes by regulating the synthesis and concentration of FlhD(2)C(2)...
  13. ncbi request reprint Role of glutathione in the formation of the active form of the oxygen sensor FNR ([4Fe-4S].FNR) and in the control of FNR function
    Q H Tran
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    Eur J Biochem 267:4817-24. 2000
    ..FNR in vitro suggest an important role for glutathione in the de novo assembly of FNR and in the reductive activation of air-oxidized FNR under anaerobic conditions...
  14. ncbi request reprint DctA- and Dcu-independent transport of succinate in Escherichia coli: contribution of diffusion and of alternative carriers
    I G Janausch
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    Arch Microbiol 176:224-30. 2001
    ..In contrast, the efflux of succinate produced during glucose fermentation was not affected in the mutants, demonstrating that, for succinate efflux, a carrier different from, or in addition to, the known Dcu and CitT carriers is used...
  15. ncbi request reprint Control of FNR function of Escherichia coli by O2 and reducing conditions
    G Unden
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    J Mol Microbiol Biotechnol 4:263-8. 2002
    ..According to this model the functional state of FNR is determined by a (rapid) inactivation of FNR by O2, and a slow (constant) reactivation with glutathione as the reducing agent...
  16. ncbi request reprint O2-sensing and O2-dependent gene regulation in facultatively anaerobic bacteria
    G Unden
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Germany
    Arch Microbiol 164:81-90. 1995
    ..O2 seems to affect the site-specific DNA binding of FNR at target genes or the formation of an active transcriptional complex with RNA polymerase...
  17. ncbi request reprint Reactivity of the N-terminal cysteine residues in active and inactive forms of FNR, and O2-responsive, Fe containing transcriptional regulator of Escherichia coli
    S Six
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Germany
    J Inorg Biochem 62:89-102. 1996
    ..In addition, a different type of interaction of Fe(II) with FNR is described. The interaction occurred also in FNR carboxymethylated at approximately three cysteine residues...
  18. pmc Identification of a third secondary carrier (DcuC) for anaerobic C4-dicarboxylate transport in Escherichia coli: roles of the three Dcu carriers in uptake and exchange
    E Zientz
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Federal Republic of Germany
    J Bacteriol 178:7241-7. 1996
    ..Mutants producing only DcuA, DcuB, or DcuC were prepared. In the mutants, DcuA, DcuB, and DcuC were each able to operate in the exchange and uptake mode...
  19. pmc Citrate sensing by the C4-dicarboxylate/citrate sensor kinase DcuS of Escherichia coli: binding site and conversion of DcuS to a C4-dicarboxylate- or citrate-specific sensor
    J Kramer
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    J Bacteriol 189:4290-8. 2007
    ..Sites C2 and C3 are essential for binding of two carboxylic groups of citrate or of C(4)-dicarboxylates; sites C1 and H are required for other essential purposes...
  20. pmc The fnr gene of Bacillus licheniformis and the cysteine ligands of the C-terminal FeS cluster
    A Klinger
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat, Mainz, Germany
    J Bacteriol 180:3483-5. 1998
    ..Transfer of the B. licheniformis gene to an fnr mutant of B. subtilis complemented the ability for synthesis of nitrate reductase during anaerobic growth...
  21. pmc Reduced apo-fumarate nitrate reductase regulator (apoFNR) as the major form of FNR in aerobically growing Escherichia coli
    F Reinhart
    Institut für Mikrobiologie und Weinforschung, Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    J Bacteriol 190:879-86. 2008
    ..ApoFNR from aerobic bacteria contained no disulfide, in contrast to apoFNR formed in vitro by air inactivation, and all Cys residues were in the thiol form...
  22. ncbi request reprint Variations in the energy metabolism of biotechnologically relevant heterofermentative lactic acid bacteria during growth on sugars and organic acids
    T Zaunmüller
    Institut für Mikrobiologie und Weinforschung, Johannes Gutenberg Universitat Mainz, Becherweg 15, 55099 Mainz, Germany
    Appl Microbiol Biotechnol 72:421-9. 2006
    ..Thus, heterofermentative LAB are able to use a variety of unusual fermentation reactions in addition to classical heterofermentation. Most of the reactions are significant for food biotechnology/microbiology...
  23. ncbi request reprint Characterization of the FNR protein of Escherichia coli, an iron-binding transcriptional regulator
    J Green
    Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, U K
    Proc Biol Sci 244:137-44. 1991
    ..A role for iron in FNR-mediated gene expression was confirmed by using cultures in which FNR was inactivated by growth in the presence of the specific chelator, ferrozine, but protected by ferrous iron...
  24. ncbi request reprint Iron content and FNR-dependent gene regulation in Escherichia coli
    F Niehaus
    Institut für Biochimie, Heinrich Heine Universitat, Dusseldorf, F R G
    FEMS Microbiol Lett 68:319-23. 1991
    ..Therefore FNR does not communicate with the iron pool regulating the Fur protein...
  25. ncbi request reprint Oxygen regulated gene expression in Escherichia coli: control of anaerobic respiration by the FNR protein
    G Unden
    Institut fur Biochemie, Heinrich Heine Universitat, Dusseldorf, Germany
    Antonie Van Leeuwenhoek 59:65-76. 1991
    ..The FNR protein in addition contains a potential nucleotide binding domain. The significance and function of this site is not clear...
  26. ncbi request reprint Isolation of intact FNR protein (Mr 30,000) of Escherichia coli
    M Trageser
    Institut fur Mikrobiologie, J W Goethe Universitat, Frankfurt, FRG
    Mol Microbiol 4:21-7. 1990
    ..The N-terminal sequence of FNR (Mr 30,000) was identical to that predicted from the fnr gene starting with the initiating methionine residue and including a four-cysteine cluster (16)Cys-X3-Cys-X2-Cys-X5-Cys(29)...
  27. pmc Transport of C(4)-dicarboxylates in Wolinella succinogenes
    R Ullmann
    Institut fur Mikrobiologie, Johann Wolfgang Goethe Universitat, D 60439 Frankfurt am Main, Germany
    J Bacteriol 182:5757-64. 2000
    ..Dicarboxylate transport via the electrogenic uniport is probably catalyzed by the DctPQM transporter and by a fourth, unknown transporter that may also operate as an electrogenic antiporter...
  28. ncbi request reprint Isolation and characterization of the Fnr protein, the transcriptional regulator of anaerobic electron transport in Escherichia coli
    G Unden
    Eur J Biochem 146:193-9. 1985
    ..Two of the four cysteine residues of the Fnr protein were alkylated by iodoacetic acid and this could have functional significance in rendering the protein redox-sensitive...
  29. ncbi request reprint On the role of cyclic AMP and the Fnr protein in Escherichia coli growing anaerobically
    G Unden
    Arch Microbiol 147:195-200. 1987
    ..This result excluded regulation of the activity of the Fnr protein by a change of concentration or by processing of the protein...
  30. ncbi request reprint Construction and properties of Escherichia coli mutants defective in two genes encoding homologous membrane proteins with putative roles in anaerobic C4-dicarboxylic acid transport
    S Six
    Department of Molecular Biology and Biotechnology, University of Sheffield, U K
    Biochem Soc Trans 21:342S. 1993
  31. ncbi request reprint A third periplasmic transport system for L-arginine in Escherichia coli: molecular characterization of the artPIQMJ genes, arginine binding and transport
    U Wissenbach
    Institut fur Biochemie, Universitat Dusseldorf, Germany
    Mol Microbiol 17:675-86. 1995
    ..It is concluded that the artPIQM artJ genes encode a third arginine-uptake system in addition to the known argT hisJQMP system of Salmonella typhimurium and E. coli and the arginine (-ornithine) carrier (aps) of E. coli...
  32. ncbi request reprint An Escherichia coli mutant containing only demethylmenaquinone, but no menaquinone: effects on fumarate, dimethylsulfoxide, trimethylamine N-oxide and nitrate respiration
    U Wissenbach
    Institut fur Biochemie, Heinrich Heine Universitat, Dusseldorf, Federal Republik of Germany
    Arch Microbiol 158:68-73. 1992
    ..In strain AN70 (ubiE) the lack of ubiquinone (Q) is due to a defect in a specific methylation step of Q biosynthesis. Synthesis of MK from DMK appears to depend on the same gene (ubiE)...
  33. ncbi request reprint Wolinella succinogenes fumarate reductase contains a dihaem cytochrome b
    C Körtner
    Institut fur Mikrobiologie, J W Goethe Universitat, Frankfurt, FRG
    Mol Microbiol 4:855-60. 1990
    ..FrdC was found to be homologous with the cytochrome b (SdhC) of the Bacillus subtilis succinate dehydrogenase, but not with the hydrophobic subunits of the fumarate reductase or succinate dehydrogenase of Escherichia coli...
  34. ncbi request reprint Generation of a proton potential by succinate dehydrogenase of Bacillus subtilis functioning as a fumarate reductase
    M Schnorpfeil
    , , Germany
    Eur J Biochem 268:3069-74. 2001
    ..The Deltapsi generated by fumarate reduction is suggested to stem from menaquinol:fumarate reductase functioning in a redox half-loop...
  35. ncbi request reprint The fumarate reductase operon of Wolinella succinogenes. Sequence and expression of the frdA and frdB genes
    F Lauterbach
    Institut fur Mikrobiologie, J W Goethe Universität Frankfurt, Federal Republic of Germany
    Arch Microbiol 154:386-93. 1990
    ..Part of the homologous peptide stretches could be assigned to domains that are involved in the binding of the substrate of the FAD prosthetic group of the enzyme...
  36. pmc Physical map location of the new artPIQMJ genes of Escherichia coli, encoding a periplasmic arginine transport system
    U Wissenbach
    Institut fur Biochemie, Heinrich Heine Universitat, Dusseldorf, Germany
    J Bacteriol 175:3687-8. 1993