Forschungsprofil Dr. Janet Vonck


  • PhD, University of Groningen, The Netherlands, 1992
  • Postdoc, University of California at Berkeley, 1992-1995
  • Staff scientist, EMBL Heidelberg, 1996
  • At the institute since 1997

Electron microscopy of protein complexes in bioenergetics

Fig. 1: A model of the purple membrane, seen from the cytoplasm. The molecule in the center, labelled N, is shown in the N state where helices E, F and G have changed conformation (Vonck, EMBO J. 2000).
Fig. 2: The proton path in bacteriorhodopsin.

A major function of biological membranes is the conversion of energy from food or light into a proton or ion gradient, which is utilised to form ATP, the energy currency of the cell. We study proteins and protein complexes involved in this process by electron crystallography of two-dimensional crystals and by single particle electron microscopy.

Halophilic archaea can utilize light energy directly using the light-driven proton pump bacteriorhodopsin. The structure of this 7-helix transmembrane protein is known at high resolution, but the mechanism of vectorial transport and the nature of conformational changes during the photocycle have long been elusive. Photocycle intermediates can be trapped in mutants and/or at low temperatures. We have studied a late intermediate, N, in the mutant F219L and succeeded in producing a three-dimensional difference map from diffraction patterns of illuminated (N) and unilluminated (ground state) crystals. The map clearly shows tilts of several helices, opening up a channel in the cytoplasmic half of the protein that enables the proton transfer in the second half of the photocycle.

Fig. 3: 3-D map of the c-rings from Ilyobacter tartaricus with 11-fold non-crystallographic symmetry applied. The hairpins are packed back-to-front, forming two concentric rings. The helices in the inner ring are very tightly packed and thus can be assigned as the glycine-rich N-terminal helices. The helices in the outer ring are kinked near the position of the conserved glutamate residue involved in Na+-translocation (Vonck et al., 2002).
Fig. 4: projection maps of c-ring crystals from Acetobacter woodii and Caldalkalibacillus thermarum strain TA2.A1 reveal 11 and 13 subunits per ring, respectively (Fritz et al., 2008, Matthies et al., 2009).

In bacteria, mitochondria and chloroplasts, a transmembrane proton or ion gradient drives the formation of ATP by F1Fo ATP synthases. Although the x-ray structure of the soluble F1 part has provided much insight into the mechanism of ATP synthesis, not much is known about the structure of the ion-translocating, membrane-embedded Fo part and the coupling of ion translocation to ATP synthesis. Fo in bacteria has a subunit composition of ab2c10-15. The c-subunits form a rotor ring attached to the γε central stalk in F1 and ab2 is part of the stator with the b subunits forming the peripheral stalk which connects the a subunit to the F1 head. Ion flow between the a subunit and the c-ring induces rotation of the γ subunit inside the F1 head by a still not fully understood mechanism.

In collaboration with the group of Thomas Meier, we study two-dimensional crystals of c-rings. We have calculated a 3-D map at 6 Å in-plane resolution of the 11-subunit c-rings from Ilyobacter tartaricus (fig. 3). The relatively simple structure combined with a wealth of biochemical data about the rings made it possible to fit a C-α model into the density. This model was successfully used for phasing three-dimensional crystals of the rings, which yielded the first atomic model of a c-ring at 2.4 Å resolution (Meier et al., Science 308 [2005] 659-662). The number of c-subunits per ring, and thus the number of ATPs formed per translocated ion, varies among different organisms. In projection maps of 2-D crystals, the number of subunits is easily visible (fig. 4).

Figure 5: 3D EM map of archaeal ATP synthase with fitted subunits (Vonck et al., 2009)

Archaea and some bacteria contain A-type ATP synthases, which are distinct from the F1Fo found in mitochondria, chloroplasts and bacteria. By single-particle electron microscopy, we have determined the 3D structure of the enzyme from the hyperthermophilic archaeon Pyrococcus furiosus at a resolution of 23 Å. Using data from LILBID mass spectroscopy, SDS-PAGE and crystal structures from homologous subunits, we were able to deduce a model with locations for every subunit. The model has a subunit composition A3B3CDFE2H2ac10 and a molecular mass of 738 kDa (fig. 5).

Fig. 6: 3D-EM map of a supercomplex from bovine heart mitochondria. An EM map of complex I (yellow) and X-ray models of complex III (red) and complex IV (green) were fitted to the map (Schäfer et al., 2007).

In mitochondria and bacteria, a proton gradient is created by the complexes of the electron transport chain. Increasing evidence in different organisms shows that the protein complexes do not float freely in the membrane, but form supercomplexes of different composition. Single particle electron microscopy (EM) is an ideal technique to study these very large protein assemblies. Eva Schäfer has determined the first 3D map of a respiratory chain supercomplex, a 1.7 MDa complex from bovine heart mitochondria containing complex I, III and IV. The map was interpreted by fitting x-ray and EM structures of the individual complexes (fig. 6).

 

Figure 7. Cryo-EM map of yeast FAS at 6 Å resolution with fitted structure. Enzymatic domains are shown in different colors and connecting structural domains in light green (Gipson et al., 2010).
Figure 8. Three cryo-EM maps of Mycobacterium tuberculosis FAS seen as side view and top view show different conformations of the protein chains (Ciccarelli et al., 2013).

The fatty acid portions of the phospholipids and glycerides in biological membranes are synthesized by the enzyme system fatty acid synthase (FAS) from acetyl-coenzyme A (CoA) and malonyl CoA. In yeast and mammals, all enzymes involved in fatty acid synthesis are organised in a large multienzyme complex. Preeti Gipson has determined a cryo-EM map of the 2.6 MDa FAS complex from yeast at ~6 Å resolution (fig. 7). At this resolution, structural elements like α-helices are easily recognizable. The EM map shows significant differences to crystal structures of the same complex. Unlike the crystal structures the EM map reveals several positions for the mobile acyl carrier protein inside the barrel, which shuttles the substrate between the enzymatic sites.

A few bacteria, including mycobacteria, contain a type I fatty acid synthase related to yeast FAS, that is involved in producing the mycolic acids that form the major component of their cell wall. One of these organisms is M. tuberculosis, the causative agent of tuberculosis. The mycolic acids give the mycobacteria an increased resistance to chemical damage and dehydration, and prevent the effective activity of hydrophobic antibiotics. Luciano Ciccarelli has determined the structure of M. tuberculosis FAS by cryo-electron microscopy and found that while similar to yeast FAS, the complex is flexible and does not display D3 symmetry. A dataset was sorted into three maps with distinct conformations, which show domain movements of up to 40 Å between them (fig. 8). These movements may play a role in accessibility of the reaction chamber to other proteins involved in fatty acid synthesis.

 

Figure 9. Cryo-EM map of Frh at 3.4 Å resolution. View down the two-fold axis of the tetrahedral complex. Each of the twelve FrhABG heterotrimers is shown in a different color (Allegretti et al., 2014).
Figure 10. A 10-Å thick slice of the map with the atomic model superimposed. At this level, a complete chain of cofactors can be seen: the [NiFe] cluster in FrhA (green and brown spheres), three FeS clusters in FrhG and one in FrhB (brown and yellow spheres), and the FAD in FrhB (yellow sticks). FrhA is green, FrhG purple, FrhB slate-blue.
Figure 11. Model of the Frh complex based on a cryo-EM map. The three proteins FrhA, FrhG and FrhB are shown in green, purple and blue, respectively. The iron-sulfur clusters are shown as spheres. Top, one FrhABG heterotrimer, bottom, the tetrahedral complex.

Methanogenic archaea use a [NiFe]-hydrogenase, Frh, for oxidation/reduction of F420, an important hydride carrier in the methanogenesis pathway from H2 and CO2. Frh accounts for about 1% of the cytoplasmic protein and forms a huge complex consisting of FrhABG heterotrimers with each a [NiFe] center, four iron-sulfur clusters and an FAD. We have determined the structure of Frh by cryo-EM. At a resolution of ~4.5Å, the quality of the maps was such that the pitch of alpha-helices, the separation of beta-strands and density for large amino acid side chains could be seen. The 1.2-MDa complex has tetrahedral symmetry and contains 12 copies of the heterotrimer, which form a spherical protein shell with a hollow core. The cryo-EM map revealed strong electron density of the chains of metal clusters running parallel to the protein shell. All three proteins were traced in the map, FrhA and FrhG based on the large and small subunit of [NiFe] hydrogenases of known structure. The polypeptide chain of FrhB, for which there was no homolog, was traced de novo from the EM map (Mills et al., 2013). 

The recent introduction of direct electron detectors with higher detective quantum efficiency and fast read-out marks the beginning of a new era in electron cryo-microscopy. Using a direct electron detector in video mode, we have reconstructed a new map at 3.36 Å resolution of Frh from only 320,000 asymmetric units (Figure 9). Videos frames were aligned by a combination of image and particle alignment procedures to overcome the effects of beam-induced motion. The density map shows all secondary structure as well as clear side chain densities for most residues (Figure 10). The full coordination of all cofactors in the electron transfer chain (a [NiFe] center, four [4Fe4S] clusters and an FAD) is clearly visible along with a well-defined substrate access channel. From the rigidity of the complex we conclude that catalysis is diffusion-limited and does not depend on protein flexibility or conformational changes (Allegretti et al., 2014).


Collaborations

  • Sonja-Verena Albers, Albert-Ludwigs-Universität Freiburg, Germany.
  • Beate Averhoff, Institute of Molecular Biosciences at Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.
  • Martin Grininger, Cluster of Excellence Macromolecular Complexes,
    Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.
  • Inga Hänelt, Institute of Biochemistry, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.
  • Thomas Meier, Imperial College London, UK.
  • Volker Müller, Institute of Molecular Biosciences at Johann Wolfgang Goethe-University, Frankfurt am Main, Germany.


Ph.D. theses

Matteo Allegretti: Structural characterization of macromolecular complexes by single-particle cryo-EM.
Goethe-Universität, Frankfurt am Main, 2016.

Luciano Ciccarelli: Mycobacterium tuberculosis type I fatty acid synthase: structure and conformational variability of a protein complex by single-particle electron cryo-microscopy. Frankfurt am Main, 2014.

Preeti Kumari: High-resolution cryo-electron microscopy study of structure and dynamics of yeast fatty acid synthase by single particle analysis. Frankfurt am Main, 2010.

Eva Schäfer: Biochemische und strukturelle Untersuchungen von Superkomplexen der Atmungskette und von F0F1-ATP-Synthasen. Darmstadt, 2006.

Tassilo Krug von Nidda: Zweidimensionale Kristallisation und elektronenkristallographische Strukturbestimmung von Membranproteinen der Energieumwandlung. Frankfurt am Main, 2002.

MSc thesis

Lisa Hielkema: University of Groningen, The Netherlands, 2016.

 

Publications

Daum, B., Vonck, J., Bellack, A., Chaudhuri, P., Reichelt, R., Albers, S.-V., Rachel, R., and Kühlbrandt, W.: Structure and in situ organisation of the Pyrococcus furiosus archaellum machinery.
eLife 6, e27470 (2017). dx.doi.org/10.7554/eLife.27470

Diskowski, M., Mehdipour, A. R., Wunnicke, D., Mills, D. J., Mikusevic,V., Bärland, N., Hoffmann, J., Morgner, N., Steinhoff, H.-J., Hummer,G., Vonck, J., and Hänelt, I.:  Helical jackknives control the gates ofthe double-pore K+ transporter KtrAB.
eLife 6, e24303 (2017). dx.doi.org/10.7554/eLife.24303

Schumacher, D., Bergeler, S., Harms, A., Vonck, J., Huneke-Vogt, S.,Frey, E., and Søgaard-Andersen, L.: The PomXYZ proteins self-organize on the bacterial nucleoid to stimulate cell division.
Dev. Cell 41, 299-314 (2017). dx.doi.org/10.1016/j.devcel.2017.04.011

Sousa, J.S., D.J. Mills, J. Vonck, W. Kühlbrandt: Functional asymmetry and electron flow in the bovine respirasome.
eLife 5, e21290 (2016) dx.doi.org/10.7554/eLife.21290

D'Imprima, E., D. J. Mills, K. Parey, U. Brandt, W. Kühlbrandt, V. Zickermann and J. Vonck: Cryo-EM structure of respiratory complex I reveals a link to mitochondrial sulfur metabolism.
BBA - Bioenergetics 1857 1935-1942 (2016). dx.doi.org/10.1016/j.bbabio.2016.09.014

Vonck, J., Parcej, D. N., and Mills, D. J.: Structure of alcohol oxidase from Pichia pastoris by cryo-electron microscopy.
PLoS ONE
11, e0159476 (2016). dx.doi.org/10.1371/journal.pone.0159476

Hahn, A., Parey, K., Bublitz, M., Mills, D. J., Zickermann, V., Vonck, J., Kühlbrandt, W., and Meier, T.: Structure of a complete ATP synthase dimer reveals the molecular basis of inner mitochondrial membrane morphology.
Mol. Cell
63, 445-456 (2016). dx.doi.org/10.1016/j.molcel.2016.05.037

Kao, W.-C., Kleinschroth, T., Nitschke, W., Baymann, F., Neehaul, Y., Hellwig, P., Richers, S., Vonck, J., Bott, M., and Hunte, C.: The obligate respiratory supercomplex from Actinobacteria.
BBA - Bioenergetics 1857 1705-1714 (2016). dx.doi.org/10.1016/j.bbabio.2016.07.009

Salzer, R., D’Imprima, E., Gold, V. A. M., Rose, I., Drechsler, M., Vonck, J., and Averhoff, B.: Topology and structure/function correlation of ring and gate forming domains in a dynamic secretin complex.
J. Biol. Chem. 291, 14448-14456 (2016). doi:10.1074/jbc.M116.724153

Chaudhuri, P., Neiner, T., D'Imprima, E., Banerjee, A., Reindl, S., Ghosh, A., Arvai, A. S., Mills, D. J., van der Does, C., Tainer, J. A., Vonck, J., and Albers, S.-V.: The nucleotide-dependent interaction of FlaH and FlaI is essential for assembly and function of the archaellum motor.
Mol. Microbiol. 99 674-685 (2016). doi:10.1111/mmi.13260

Schuchmann, K., Vonck, J., & Müller, V.: A hydrogen-dependent CO2 reductase forms filamentous structures.
FEBS J. 283 1311-1322 (2016). doi:10.1111/febs.13670

Allegretti, M., Klusch, N., Mills, D. J., Vonck, J., Kühlbrandt, W., and Davies, K.M.: Horizontal membrane-intrinsic α-helices in the stator a-subunit of an F-type ATP synthase.
Nature
521 237-240 (2015). doi: 10.1038/nature14185

Fischer, M., Rhinow, D., Zhu, Z., Mills, D.J., Zhao, Z.K., Vonck, J., and Grininger, M.: Cryo-EM structure of fatty acid synthase (FAS) from Rhodosporidium toruloides provides insights into the evolutionary development of fungal FAS.
Protein Sci. 24, 987-995 (2015). doi: 10.1002/pro.2678

Allegretti, M., Mills, D. J., McMullan, G., Kühlbrandt, W., & Vonck, J.: Atomic model of the F420-reducing [NiFe] hydrogenase by electron cryo-microscopy using a direct electron detector.
eLife 3 e01963 (2014). doi: 10.7554/elife.01963

Zhang, C., Allegretti, M., Vonck, J., Langer, J. D., Marcia, M., Peng, G., and Michel, H.: Production of a fully assembled and active form of Aquifex aeolicus F1FO ATP synthase in Escherichia coli.
Biochim. Biophys. Acta 1840 34-40 (2014). doi: 10.1016/j.bbagen.2013.08.023

Ciccarelli, L., Connell, S.R., Enderle, M., Mills, D.J., Vonck, J., and Grininger, M.: Structure and conformational variability of the Mycobacterium tuberculosis fatty acid synthase multienzyme complex.
Structure 21 1251-1257 (2013). doi: 10.1016/j.str.2013.04.023

Collinson, I., Vonck, J., and Hizlan, D.: Using 2D crystals to analyze the structure of membrane proteins.
In: Membrane Biogenesis: Methods and Protocols (Methods in Molecular Biology 1033), eds. Rapaport, D. and Herrmann, J.M., Humana Press, Chapter 4 pp. 47-65 (2013). doi: 10.1007/978-1-62703-487-6_4

Mills, D.J., Vitt, S., Strauss, M., Shima, S., and Vonck, J.: De novo modeling of the F420-reducing [NiFe] hydrogenase from a methanogenic archaeon by cryo-electron microscopy.
eLife 2 e00218 (2013). doi: 10.7554/elife.00218

Mills, D.J. and Vonck, J.: Choice and maintenance of equipment for electron crystallography.
in: Electron Crystallography of Soluble and Membrane Proteins: Methods and Protocols (Methods in Molecular Biology 955), eds. Schmidt-Krey, I. and Cheng, Y., Springer Science+Business Media, New York, Chapter 19 pp. 331-351 (2013). doi: 10.1007/978-1-62703-176-9_19

Banerjee, A., Ghosh, A., Mills, D.J., Kahnt, J., Vonck, J., and Albers, S.-V.: FlaX, a unique component of the crenarchaeal archaellum, forms oligomeric ring-shaped structures and interacts with the motor ATPase FlaI.
J. Biol. Chem. 287 43322-43330 (2012). doi: 10.1074/jbc.M112.414383

Burkhardt, J., Vonck, J., Langer, J.D., Salzer, R., and Averhoff, B.: Unusual ααβαββα-fold of PilQ from T. thermophilus mediates ring formation and is essential for piliation.
J. Biol. Chem. 287 8484-8494 (2012). doi: 10.1074/jbc.M111.334912

Hakulinen, J.K., Klyszejko, A.L., Hoffmann, J., Eckhardt-Strelau, L., Brutschy, B., Vonck, J., and Meier, T.: A structural study on the architecture of the bacterial ATP synthase Fo motor.
Proc. Natl. Acad. Sci. USA 109 E2050-E2056 (2012). doi: 10.1073/pnas.1203971109

Hizlan, D., Robson, A., Whitehouse, S., Gold, V.A., Vonck, J., Mills, D., Kühlbrandt, W., and Collinson, I.: Structure of the SecY complex unlocked by a preprotein mimic.
Cell Reports 1 21-28 (2012).

Pogoryelov, D., Klyszejko, A.L., Krasnoselska, G.O., Heller, E.-M., Leone, V., Langer, J.D., Vonck, J., Müller, D.J., Faraldo-Gómez, J.D., and Meier, T.: Engineering rotor ring stoichiometries in ATP synthases.
Proc. Natl. Acad. Sci. USA 109 E1599-E1608 (2012).

Vonck, J.: Supramolecular structure of the respiratory chain.
in: A structural perspective on respiratory complex I: structure and function of NADH:ubiquinone oxidoreductase; ed. Sazanov, L.A., Springer Science+Business Media, Dordrecht (Netherlands), Chapter 12, pp. 247-277 (2012).

Burkhardt, J., Vonck, J., and Averhoff, B.: Structure and function of PilQ, a secretin of the DNA transporter from the thermophilic bacterium Thermus thermophilus HB27.
J.
Biol. Chem. 286 (12) 9977-9984 (2011).

Goswami, P., Paulino, C., Hizlan, D., Vonck, J., Yildiz, Ö., and Kühlbrandt, W.: Structure of the archaeal Na+/H+ antiporter NhaP1 and functional role of transmembrane helix 1.
EMBO J. 30 439-449 (2011).

Matthies, D., Haberstock, S., Joos, F., Dötsch, V., Vonck, J., Bernhard, F., and Meier, T.: Cell-free expression and assembly of ATP synthase.
J. Mol. Biol. 413 593-603 (2011).

Gipson, P., Mills, D.J., Wouts, R., Grininger, M., Vonck, J., and Kühlbrandt, W.: Direct structural insight into the substrate shuttling mechanism of yeast fatty acid synthase by electron cryo-microscopy.
Proc. Natl. Acad. Sci. USA 107 (20) 9164-9169 (2010). doi: 10.1073/pnas.0913547107

Kumar, J., Sreeramulu, S., Schmidt, T.L., Richter, C., Vonck, J., Heckel, A., Glaubitz, C., and Schwalbe, H.: Prion protein amyloid formation involves structural rearrangements in the C-terminal domain.
ChemBioChem 11 1208-1213 (2010).

Müller, V., Pisa, K.Y., and Vonck, J.: ATP-Synthase der Archäen - Neue Einblicke in die Struktur und Funktion eines Energiewandlers.
Biospektrum 16 (1) 19-21 (2010).

Rhinow, D., Vonck, J., Schranz, M., Beyer, A., Gölzhäuser, A., and Hampp, N.: Ultrathin carbon nanosheets as support films for structural analysis of biological specimens.
Phys. Chem. Chem. Phys. 12 4345-4350 (2010). doi: 10.1039/b923756a

Bron, P. and Vonck, J.: Two-Dimensional Crystals.
in: Handbook of Cryo-Preparation Methods for Electron Microscopy, (Methods in Visualization Series), eds. Cavalier, A., Spehner, D., and Humbel, B. M.; CRC Press, Boca Raton (USA), Part II Chapter 8 pp. 191-218 (2009).

Matthies, D., Preiss, L., Klyszejko, A.L., Muller, D.J., Cook, G.M., Vonck, J., and Meier, T.: The c13 ring from a thermoalkaliphilic ATP synthase reveals an extended diameter due to a special structural region.
J. Mol. Biol. 388 (3) 611-618 (2009).

Seelert, H., Dani, D.N., Dante, S., Hauss, T., Krause, F., Schäfer, E., Frenzel, M., Poetsch, A., Rexroth, S., Schwassmann, H.J., Suhai, T., Vonck, J., and Dencher, N.A.: From protons to OXPHOS supercomplexes and Alzheimer’s disease: structure-dynamics-function relationships of energy-transducing membranes.
Biochim. Biophys. Acta
- Bioenergetics 1787 657-671 (2009).

Vonck, J., Pisa, K.Y., Morgner, N., Brutschy, B., and Müller, V.: Three-dimensional structure of A1Ao ATP synthase from the hyperthermophilic archaeon Pyrococcus furiosus by electron microscopy.
J. Biol. Chem.
284 (15) 10110-10119 (2009).

Vonck, J. and Schäfer, E.: Supramolecular organization of protein complexes in the mitochondrial inner membrane.
Biochim. Biophys. Acta
- Molecular Cell Research 1793 117-124 (2009).

Fritz, M., Klyszejko, A.L., Morgner, N., Vonck, J., Brutschy, B., Muller, D.J., Meier, T., and Müller, V.: An intermediate step in the evolution of ATPases - a hybrid F0-V0 rotor in a bacterial Na+ F1F0 ATP synthase.
F
EBS J. 275 1999-2007 (2008).

Johansson, P., Wiltschi, B., Kumari, P., Kessler, B., Vonrhein, C., Vonck, J., Oesterhelt, D., and Grininger, M.: Inhibition of the fungal fatty acid synthase type I multienzyme complex.
Proc. Natl. Acad. Sci. USA
105 (35) 12803-12808 (2008).

Schäfer, E., Dencher, N.A., Vonck, J., and Parcej, D.N.: Three-dimensional structure of the respiratory chain supercomplex I1III2IV1 from bovine heart mitochondria.
Biochem.
46 12579 -12585 (2007).

Shastri, S., Vonck, J., Haase, W., Pfleger, N., Kühlbrandt, W.,  and Glaubitz, C.: Proteorhodopsin: characterisation of 2D crystals by electron microscopy and solid state NMR.
Biochim. Biophys. Acta – Biomembranes 1768 3012-3019 (2007).

Stocker, A., Keis, S., Vonck, J., Cook, G.M., and Dimroth, P.: The structural basis for unidirectional rotation of thermoalkaliphilic F1-ATPase.
Structure
15 904-914 (2007).

Meier, T., Ferguson, S.A., Cook, G.M., Dimroth, P., and Vonck, J.: Structural investigations of the membrane-embedded rotor ring of F-ATPase from Clostridium paradoxum.
J. Bacteriol
. 188 7759-7764 (2006).

Schäfer, E., Seelert, H., Reifschneider, N.H., Krause, F., Dencher, N.A., and Vonck, J.: Architecture of active mammalian respiratory chain supercomplexes.
J. Biol. Chem.
281 15370-15375 (2006).

Pogoryelov, D., Yu, J., Meier, T., Vonck, J., Dimroth, P., and Müller, D.J.: The c15 ring of the Spirulina platensis F-ATP synthase: F1/F0 symmetry mismatch is not obligatory.
EMBO Rep. 6 1045-1051 (2005).

Meier, T., Matthey, U., von Ballmoos, C., Vonck, J., Krug von Nidda, T., Kühlbrandt, W., and Dimroth, P.: Evidence for structural integrity in the undecameric c-rings isolated from sodium ATP synthases.
J. Mol. Biol.
325 389-397 (2003).

Vonck, J., Krug von Nidda, T., Meier, T., Matthey, U., Mills, D.J., Kühlbrandt, W., and Dimroth, P.: Molecular architecture of the undecameric rotor of a bacterial Na+-ATP synthase.
J. Mol. Biol.
321 307-316 (2002).

Behlau, M., Mills, D.J., Kühlbrandt, W., Quader, H., and Vonck, J.: Projection structure of the monomeric porin OmpG at 6 Å resolution.
J. Mol. Biol.
305 71-77 (2001).

Vonck, J.: Parameters affecting specimen flatness of two-dimensional crystals for electron crystallography.
Ultramicroscopy
85 123-129 (2000).

Vonck, J.: Structure of the bacteriorhodopsin mutant F219L N-intermediate revealed by electron crystallography.
EMBO J
. 19 2152-2160 (2000).

Kontaktinformationen:

Max-Planck-Institut für Biophysik

Dr. Janet Vonck
Department of Structural Biology

Tel.: +49 (0) 69 6303-3004
Fax:    
+49 (0) 69 6303-3002

E-Mail:janet.vonck(at)biophys.mpg.de

Vonck - Gruppenmitglieder:

Project leader

  • Dr. Janet Vonck

PhD students

MSc students

  • Natalie Bärland
  • Nina Salustros