Hauska´s Lab Home Page

Adress:

Telefone: (0941) 943 3031
Telefax: (0941) 943 3352
e-mail: guenther.hauska@biologie.uni-regensburg.de

Career:

1968-1970 Postdoc with R.E.McCarty and E.Racker, Cornell University

1971-1976 Research assistant with A.Trebst, Ruhr-Universität Bochum

1973 Habilitation in biochemistry, Ruhr-Universität Bochum

since 1976 Professor at the Institut für Botanik, Universität Regensburg

1989 - 1990 Sabbatical with N.Nelson, Roche Institute of Molecular Biology, Nutley, NJ USA 

Research Interest:

Further research interests: see also here! (Non-official homepage!)
 
 

Research contributions in the past /collaborations:

• The universal topography of energy conserving electron transport chains emerged after the finding that plastocyanin was a luminal protein in thylakoids, in analogy to the location of cytochrome c in the intermembrane space of mitochondria (1971 with McCarty and Racker/ ref. 1). Later this picture was substantiated by the periplasmic localisation of cytochrome c2 in purple bacteria (1975 with Prince, Crofts and the Melandris/ ref. 2).
• Q-loops in the electron transport chains can be replaced by artificial, lipohilic and hydrogen carrying redox systems. This concept was termed "artificial energy conservation" and helped to clear the confusion about phosphorylation sites, especially in chloroplasts (1974 with Trebst/ ref. 3 and review 1).
• The physiological redox systems ubi-, plasto- and menaquinol/-quinone, in spite of their long isoprenoid chains and against theoretical considerations, were shown to catalayze fast proton transport through the membrane of lipid vesicels, from external dithionite to trapped ferricyanide (1979/ ref. 4).
• Photophosphorylation was reconstituted in a minimal system comprising the P700-reaction center, the redox system ascorbate/PMS, and the coupling factor complex CF1CFo (1980 with Nelson/ ref. 5).
• The proton translocating cytochrome b₆f-complex was isolated from chloroplasts (1981/ ref. 6) and from a cyanobacterium (1982/ ref. 7), as well as the cytochrome bc₁-complex from Rhodobacter (1982/ ref. 8), all in functional form. Quinol oxidoreductase activity was coupled to electrochemical proton potential formation after incorporation into liposomes (1983/ ref. 9). These complexes have been found to be simpler in structure than their mitochondrial counterparts, essentially consisting of the three redox center carrying polypeptides cytochrome c₁/f, the Rieske FeS-center und the double heme protein cytochrome b (1983 ref. 10). In the b₆f-complexes the cytochrome b is split into cytochrome b₆ plus subunit IV (s. reviews 2 and 5).
• The finding that the shorter cytochrome b₆ contained both hemes (1983/ ref. 10) was crucial for the structural modelling of cytochrome b in bc-complexes in general (s. reviews 2 and 5). Another important result on these lines was the demonstration of heme-heme electron transfer in cytochrome b6 (1988 ref. 11).
• The menaquinol oxidizing, low potential form of the bc-complex in Chlorobium exhibits features in the cytochrome b-gene which combines characteristics of bc₁- and b₆f-types (ref. 12 and review 5). The low potential form of the Riese FeS-cluster in this complex is based on the loss of an H-bond from a serine (S263 in beef heart mitochondria) to a Fe-Fe bridging sulfur atom (ref. 12 and Iwata et al. 1996, Structure 4: 567-579, Denke et al. 1998 J. Biol. Chem. 273: 9085-9093).
• The similarities of the Chlorobium P840-reaction center (RC) to the P700-RC of photosystem I have been substantiated by characterizing a transcription unit for the core protein plus a double FeS-center protein. Noteworthy, this RC, together with the one from heliobacteria, is of homodimeric structure in contrast to the other, heterodimeric RCs (s. ref.s 11, 14, 18-20, reviewed in ref. 24).
• More recently we have turned to the characterization of sulfide-quinone oxidoreductases, especially from Rhodobacter capsulatus, which seem to be universal flavoproteins of relatively simple structure for a quinol reducing entity (with Etana Padan and Yosepha Shahak, Israel; s. ref. 16, 17, 20, 23, 25, review 6).

Current lines of research:

1. We are attempting to crystallize the homodomeric P840-RC (collaboration with Petra Fromme / Berlin, Nathan Nelson / Tel Aviv, Georgios Tsiotis / Iraklion, Greece).
2. We are pursuing to elucidate bc-complexes of phylogenetic old bacteria like the genera Aquifex and Chloroflexus to find still further variants in addition to Chlorobium(together with Michael Schütz and Wolfgang Nitschke / Marseille).
3. We have succeeded in purifying the sulfide-quinone oxidoreductase from Rhodobacter capsulatus to homogeneity, and have cloned, sequenced and expressed its gene. We are now investigating its catalytic mechanism and its regulation (collaboration with E.Padan/Jerusalem and Y.Shahak/Bet Dagan funded by the DFG), as well as its possible use in microsensing of sulfide (Otto Wolfbeis/Department of Analytical Chemistry, Chemo- and Biosensors).
4. We have become interested in the redox sensing role of the b₆f-complex (ref. 14), and presently investigate its role in heterocyst formation of filamentous cyanobacteria (together with Iris Maldener).

Selected References

1. Hauska G, McCarty R E, Berzborn R J and Racker E (1971), Partial resolution and reconstitution of the enzymes catalyzing photophosphorylation VII. The function of plastocyanin and its reaction with a specific antibody, J. Biol. Chem. 246, 3524 - 3531
2. Prince R C, Baccarini-Melandri A, Hauska G, Melandri A B and Crofts A R (1975), Asymmetry of an energy transducing membrane; the location of cytochrome c2 in Rhodopseudomonas sphaeroides and Rhodopseudomonas capsulata., Biochim. Biophys. Acta 387, 212 - 227
3. Hauska G, Trebst A and Reimer S (1974), Native and artificial energy-conserving sites in cyclic photophosphorylation systems with photosystem I., Biochim. Biophys. Acta 357, 1 - 13
4. Futami A, Hurt E and Hauska G (1979), Vectorial redox reactions of physiological quinones I. Requirement of a minimum of length of the isoprenoid side chain, Biochim. Biophys. Acta 547, 583 - 596
5. Hauska G, Orlich G, Samoray D and Nelson N (1980), Reconstitution of photosynthetic energy conservation - photophosphorylation in liposomes containing P700-reaction centers and DCCD-sensitive ATPase, Eur. J. Biochem. 111, 535 - 543
6. Hurt E C and Hauska G (1981), A Cytochrome b₆f Complex of Five Polypeptides with Plastoquinol-Plastocyanin Oxidoreductase Activity from Spinach Chloroplasts,. Eur. J. Biochem. 117, 591 - 599
7. Krinner M, Hauska G, Hurt E and Lockau W (1982), A Cytochrome b₆f Complex with Plastoquinol-Plastocyanin Oxidoreductase Activity from Anabaena variabilis, Biochim, Biophys. Acta 681, 110 - 117
8. Gabellini N, Bowyer J R, Hurt E, Melandri B A and Hauska G (1982), A Cytochrome bc1 Complex with Ubiquinol-Cytochrome c2 Oxidoreductase Activity from Rhodopseudomonas sphaeroides GA, Eur. J. Biochem. 126, 105 - 111
9. Hurt E C and Hauska G (1983), Cytochrome b6 from Isolated Cytochrome b6f Complexes - Evidence for two Spectral Forms with different Midpoint Potentials, FEBS Lett. 153, 413 - 419
10. Hurt E C, Gabellini N, Shahak Y, Lockau W and Hauska G (1983), Extra Proton Translocation and Membrane Potential Generation - Universal Properties
11. of Cytochrome bc1/b6f Complexes Reconstituted into Liposomes, Arch. Biochem.Biophys. 225, 879 - 885
12. Hurt E and Hauska G (1984), Purification of Membrane-Bound Cytochromes and a Photoactive P840 Protein Complex of the Green Sulfur Bacterium Chlorobium limicola f. thiosulfatophilum, FEBS Lett. 168, 149 - 154
13. Nitschke W, Hauska G and Crofts AR (1988), Fast Electron Transfer from Low- to High-Potential Cytochrome b6 in Isolated Cytochrome b6f-Complex, FEBS Letters 232, 204-208
14. Gal A, Hauska G, Herrmann R and Ohad I (1990), Interaction between Licht Harvesting Chlorophyll a/b-Protein (LHCII)-Kinase and Cytochrome b6f-Complex: In vitro Control of Kinase Activity, J.Biol.Chem. 265, 19742-19749
15. Büttner M, Xie D-L, Nelson H, Pinther W, Hauska G and Nelson N (1992), Photosynthetic Reaction Center Genes in Green Sulfur Bacteria and in Photosystem 1 are related, Proc.Natl.Acad.Sci.USA 89, 8135-8139
16. Shahak Y, Klughammer C, Schreiber U, Padan E, Herrmann I and Hauska G (1994), Sulfide-Quinone and Sulfide-Cytochrome Reduction in Rhodobacter capsulatus, Photosynth.Res. 39, 175-181
17. Schütz M, Zirngibl S, le Coutre J, Büttner M, Xie D-L, Nelson N, Deutzmann N and Hauska G (1994), A Transcription Unit for the Rieske FeS-Protein and Cytochrome b in Chlorobium limicola Combines Characteristics of the bc1/b6f-Types, Photosynth.Res. 39, 163-174
18. Klughammer C, Hager C, Padan E, Schütz M, Schreiber U, Shahak Y und Hauska G (1995), Reduction of cytochromes with menaquinol and sulfide in membranes from green sulfur bacteria, Photosynth.Res. 43, 27-34
19. Hager-Braun C, Xie D-L, Jarosch U, Herold E, Büttner M, Zimmermann R, Deutzmann R, Hauska G und Nelson N (1995), Stable photobleaching of P840 in Chlorobium reaction center preparations: Presence of the 42-kDa bacteriochlorophyll a protein and a 17-kDa polypeptide, Biochemistry 34, 9617-9624
20. Frankenberg N, Hager-Braun C, Feiler U, Fuhrmann M, Rogl H, Schneebauer N, Nelson N and Hauska G (1996), P840-reaction centers from Chlorobium tepidum - quinone analysis and functional reconstitution into lipid vesicles, Photochem.Photobiol., 64,14-19
21. Schütz M, Shahak Y, Padan E und Hauska G (1997), The Sulfide-Quinone-Reductase from Rhodobacter capsulatus: Purification, Sequencing and Expression, JBC., 272, 9890-9894
22. Hager-Braun C, Jarosch U, Hauska G, Nitschke W and Riedel A (1997), The terminal electron acceptors of green sulfur bacterial reaction centre in EPR. Photosynth. Res., 51, 127-136
23. Tsiotis G, Hager-Braun C, Wolpensinger B, Engel A and Hauska G (1997) Structural analysis of the photosynthetic reaction center from the green sulfur bacterium Chlorobium tepidum. Biochim. Biophys.Acta 1322, 163-172
24. Schütz M, Griesbeck C, Bronstein M, Maldener I, Shahak Y, Padan E and Hauska G (1998) Sulfide-Quinone Reductase (SQR) of Rhodobacter capsulatus: expression, induction and inactivation. In: Garab G (ed.) International Congress on Photosynthesis (Budapest, 1998)
25. Schütz M, Klughammer C, Griesbeck C, Quentmeier A, Schreiber U, Friedrich CG und Hauska G (1998) Sulfide-quinone reductase (SQR) activity in membranes of the chemotrophic bacterium Paracoccus denitrificans GB17. Arch. Microbiol. 170, 353-360
26. Griesbeck C, Hager-Braun C, Rogl H und Hauska G (1998) Quantitation of P840 reaction center preparations from Chlorobium tepidum: chlorophylls and FMO-protein. Biochim. Biophys. Acta 1365, 285-293
27. Rémigy H-W, Stahlberg, H, Fotiadis D, Mueller S, Wolpensinger B, Engel A, Hauska G and Tsiotis G(1999) The Reaction Center from the Green Sulfur Bacterium Chlorobium tepidum: a Structural Analysis by Scanning Transmission Electron Microscopy, J.Mol.Biol., 290: 851-858
28. Schütz M, Maldener I, Griesbeck C and Hauska G (1999) Sulfide-Chinon Reductase from Rhodobacter capsulatus - Requirement for Growth, Periplasmic Localization and Extension of Gene Sequence Analysis,  J.Bacteriol.,181: 6516-6523
29. Dirmeier R., Hauska G and Stetter K (1999) ATP Synthesis at 100°C by an ATPase purified from the hyperthermophilic archeon Pyrodictium abyssii, FEBS Letters 467, 101-104
30. Nübel T, Klughammer C, Huber R, Hauska G and Schütz M (2000) Sulfide-quinone reductase in membranes of the hyperthermophilic bacterium Aquifex aeolicus (VF5), Arch. Microbiol. 173, 233-44

Reviews:

1. Hauska G and Trebst A (1977), in: Current Topics in Bioenergetics (D. R. Sanadi ed.), Proton translocation in chloroplasts Vol. 6, 151 - 220, Acad. Pres
2. Hauska G, Hurt E, Gabellini N and Lockau W (1983), Comparatative Aspects of Quinol-Cytochrome c/Plastocyanin Oxidoreductases, Biochim. Biophys. Acta 726, 97 - 133
3. Hauska G, Nitschke W and Herrmann R (1988), Amino Acid Identities in the Three Redox Center Carrying Polypeptides of Cytochrome bc1/b6f-Complexes, J. Bioenerg. Biomemb. 20, 211-228
4. Feiler U and Hauska G (1995), The Reaction Centre from Green Sulphur Bacteria, In: Advances in Photosynthesis, Anoxygenic Photosynthetic Bacteria (Blankenship RE, Madigan MT, Bauer CE eds.), pp 665-685, Kluwer Acad.Publ.
5. Hauska G, Schütz M and Büttner M (1996), The cytochrome b6f complex - composition, structure and function, In: Advances in Photosynthesis, Oxygenic Photosynthesis (DR.Ort and Yokum CF eds.) Vol. 4, Kluwer Acad.Publ., pp. 377-398
6. Shahak Y, Schütz M, Bronstein M, Griesbeck C, Hauska G und Padan E (1999) Sulfide-dependent anoxygenic photosynthesis in prokaryotes: Sulfide-quinone reductase (SQR) the initial step. In: Peschek GA, Löffelhardt W und Schmetterer G (eds.) Proceedings of the 9th International Symposium Phototrophic Procaryotes (Vienna, 1997). Plenum Press, New York, pp 217-228
7. Griesbeck C, Hauska G and Schütz M (2000) Biological Sulfide Oxidation: Sulfide-Quinone Reductase (SQR), the Primary Reaction, Recent Research Developments in Microbiology 4, 179-203 (Download PDF-file)