A5005562570- Photosynthetic Processes and Mechanisms
- ATP Synthase and ATPases Research
- Mitochondrial Function and Pathology
- Enzyme Structure and Function
- Neural Networks and Applications
- Metalloenzymes and iron-sulfur proteins
- Advanced Electron Microscopy Techniques and Applications
- Fuzzy Logic and Control Systems
- RNA and protein synthesis mechanisms
- Bacterial Genetics and Biotechnology
- Metabolism and Genetic Disorders
- Protein Structure and Dynamics
- Amino Acid Enzymes and Metabolism
- Adipose Tissue and Metabolism
- RNA modifications and cancer
- Lipid Membrane Structure and Behavior
- Peroxisome Proliferator-Activated Receptors
- Hemoglobin structure and function
- Microbial Metabolic Engineering and Bioproduction
- RNA Interference and Gene Delivery
- Advanced X-ray Imaging Techniques
- Metabolomics and Mass Spectrometry Studies
- Electron and X-Ray Spectroscopy Techniques
- Erythrocyte Function and Pathophysiology
- Membrane-based Ion Separation Techniques
Max Planck Institute of Biophysics
2015-2025
Max Planck Society
2004-2019
MRC Laboratory of Molecular Biology
2017
Harvard University
2016
University of Helsinki
2012
University of Southampton
1994-2002
European Molecular Biology Laboratory
1997-1999
University of Hertfordshire
1994
University of Missouri
1991
University of Birmingham
1976-1990
The chloroplast adenosine triphosphate (ATP) synthase uses the electrochemical proton gradient generated by photosynthesis to produce ATP, energy currency of all cells. Protons conducted through membrane-embedded Fo motor drive ATP synthesis in F1 head rotary catalysis. We determined high-resolution structure complete cF1Fo complex cryo-electron microscopy, resolving side chains 26 protein subunits, five nucleotides head, and pathway from rotor ring. flexible peripheral stalk redistributes...
We determined the structure of a complete, dimeric F1Fo-ATP synthase from yeast Yarrowia lipolytica mitochondria by combination cryo-EM and X-ray crystallography. The final resolves 58 60 dimer subunits. Horizontal helices subunit in Fo wrap around c-ring rotor, total six vertical assigned to subunits a, b, f, i, 8 span membrane. Subunit (A6L human) is an evolutionary derivative bacterial b subunit. On lumenal membrane surface, f establishes direct contact between two monomers. Comparison...
Coupling transcription and translation In bacteria, the of DNA into mRNA by RNA polymerase is coupled to that protein ribosome. How this coupling achieved has been unclear. Kohler et al. show ribosome from Escherichia coli can form a so-called expressome complex. Electron microscopy structural analysis, together with functional experiments, revealed details The could allow prevent transcriptional pausing, backtracking, termination. Science , issue p. 194
F1Fo-adenosine triphosphate (ATP) synthases make the energy of proton-motive force available for energy-consuming processes in cell. We determined single-particle cryo-electron microscopy structure active dimeric ATP synthase from mitochondria Polytomella sp. at a resolution 2.7 to 2.8 angstroms. Separation 13 well-defined rotary substates by three-dimensional classification provides detailed picture molecular motions that accompany c-ring rotation and result synthesis. Crucially, F1 head...
Respirasomes are macromolecular assemblies of the respiratory chain complexes I, III and IV in inner mitochondrial membrane. We determined structure supercomplex I1III2IV1 from bovine heart mitochondria by cryo-EM at 9 Å resolution. Most protein-protein contacts between complex membrane mediated supernumerary subunits. Of two Rieske iron-sulfur cluster domains dimer, one is resolved, indicating that this domain immobile unable to transfer electrons. The central position active monomer I...
Many pathogenic bacteria produce pore-forming toxins to attack and kill human cells. We have determined the 4.5 Å structure of ~2.2 MDa pore complex pneumolysin, main virulence factor Streptococcus pneumoniae, by cryoEM. The pneumolysin is a 400 ring 42 membrane-inserted monomers. Domain 3 soluble toxin refolds into two ~85 β-hairpins that traverse lipid bilayer assemble 168-strand β-barrel. stabilized salt bridges between adjacent subunits an internal α-barrel. apolar outer barrel surface...
The introduction of direct electron detectors with higher detective quantum efficiency and fast read-out marks the beginning a new era in cryo-microscopy. Using FEI Falcon II detector video mode, we have reconstructed map at 3.36 Å resolution 1.2 MDa F420-reducing hydrogenase (Frh) from methanogenic archaea only 320,000 asymmetric units. Videos frames were aligned by combination image particle alignment procedures to overcome effects beam-induced motion. density shows all secondary structure...
In biological processes, such as fission, fusion and trafficking, it has been shown that lipids of different shapes are sorted into regions with membrane curvatures. This lipid sorting hypothesized to be due the coupling between curvature lipid's spontaneous curvature, which is related molecular shape. On other hand, theoretical predictions simulations suggest preference lipids, shape alone, weaker than observed in processes. To distinguish these views, we have directly measured preferences...
Respiratory complex I is a redox-driven proton pump, accounting for large part of the electrochemical gradient that powers mitochondrial adenosine triphosphate synthesis. Complex dysfunction associated with severe human diseases. Assembly one-megadalton in inner membrane requires assembly factors and chaperones. We have determined structure from aerobic yeast Yarrowia lipolytica by electron cryo-microscopy at 3.2-Å resolution. A ubiquinone molecule was identified access path to active site....
Hemes switch spots in a terminal oxidase Reduction of molecular oxygen to water is the driving force for respiration aerobic organisms and catalyzed by several distinct integral membrane complexes. These include an exclusively prokaryotic enzyme, cytochrome bd–type quinol oxidase, which potential antimicrobial target. Safarian et al. determined high-resolution cryo–electron microscopy structure this enzyme from enteric bacterium Escherichia coli . Comparison homolog reveals complete...
Mitochondrial complex I has a key role in cellular energy metabolism, generating major portion of the proton motive force that drives aerobic ATP synthesis. The hydrophilic arm L-shaped ~1 MDa membrane protein transfers electrons from NADH to ubiquinone, providing drive pumping at distant sites arm. critical steps conversion are associated with redox chemistry ubiquinone. We report cryo-EM structure complete mitochondrial yeast Yarrowia lipolytica both deactive form and after capturing...
Mitochondrial NADH:ubiquinone oxidoreductase (complex I) is a 1-MDa membrane protein complex with central role in energy metabolism. Redox-driven proton translocation by I contributes substantially to the motive force that drives ATP synthase. Several structures of from bacteria and mitochondria have been determined, but its catalytic mechanism has remained controversial. We here present cryo-EM structure Yarrowia lipolytica at 2.1-Å resolution, which reveals positions more than 1600...
Abstract Potassium homeostasis is vital for all organisms, but challenging in single-celled organisms like bacteria and yeast immobile plants that constantly need to adapt changing external conditions. KUP transporters facilitate potassium uptake by the co-transport of protons. Here, we uncover molecular basis transport this widely distributed family. We identify importer KimA from Bacillus subtilis as a member family, demonstrate it functions K + /H symporter report 3.7 Å cryo-EM structure...
Abstract Infection of the human stomach by Helicobacter pylori remains a worldwide problem and greatly contributes to peptic ulcer disease gastric cancer. Without active intervention approximately 50% world population will continue be infected with this pathogen. Current eradication, called triple therapy, entails proton-pump inhibitor two broadband antibiotics, however resistance either clarithromycin or metronidazole is greater than 25% rising. Therefore, there an urgent need for targeted,...
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 about 1% cytoplasmic protein forms huge complex consisting FrhABG heterotrimers with each [NiFe] center, four Fe-S clusters FAD. Here, we report structure determined by near-atomic resolution cryo-EM without bound substrate F420. The polypeptide chains FrhB, which there was no homolog, traced de novo EM map. 1.2-MDa...
We have used a combination of electron cryo-tomography, subtomogram averaging, and crystallographic image processing to analyse the structure intact bovine F(1)F(o) ATP synthase in 2D membrane crystals. ATPase assays mass spectrometry analysis crystals confirmed that enzyme complex was complete active. The matrix-exposed region determined at 24 Å resolution by averaging repositioned into tomographic volume reveal crystal packing. complexes are inclined 16° relative plane, resulting zigzag...
ATP synthases produce by rotary catalysis, powered the electrochemical proton gradient across membrane. Understanding this fundamental process requires an atomic model of pathway. We determined structure intact mitochondrial synthase dimer electron cryo-microscopy at near-atomic resolution. Charged and polar residues a-subunit stator define two aqueous channels, each spanning one half Passing through a conserved membrane-intrinsic helix hairpin, lumenal channel protonates acidic glutamate in...
Yeast fatty acid synthase (FAS) is a 2.6-MDa barrel-shaped multienzyme complex, which carries out cyclic synthesis of acids. By electron cryomicroscopy single particles we obtained three-dimensional map yeast FAS at 5.9-Å resolution. Compared to the crystal structures fungal FAS, EM reveals major differences and new features that indicate considerably different arrangement complex in solution compared structures, as well high degree variance inside barrel. Distinct density regions reaction...
The Sec complex forms the core of a conserved machinery coordinating passage proteins across or into biological membranes. bacterial SecYEG interacts with ATPase SecA translating ribosomes to translocate secretory and membrane accordingly. A truncated preprotein competes physiological full-length substrate primes protein-channel for transport. We have employed electron cryomicroscopy two-dimensional crystals determine structure unlocked by preprotein. Its visualization in native environment...