A5065260044- Porphyrin Metabolism and Disorders
- Metalloenzymes and iron-sulfur proteins
- Microbial metabolism and enzyme function
- Metabolism and Genetic Disorders
- Enzyme Structure and Function
- Amino Acid Enzymes and Metabolism
- Anaerobic Digestion and Biogas Production
- Metal-Catalyzed Oxygenation Mechanisms
- Hemoglobin structure and function
- Methane Hydrates and Related Phenomena
- Photosynthetic Processes and Mechanisms
- Heme Oxygenase-1 and Carbon Monoxide
- Microbial Fuel Cells and Bioremediation
- Microbial Metabolic Engineering and Bioproduction
- Folate and B Vitamins Research
- Chemical Reactions and Isotopes
- Biofuel production and bioconversion
- Biochemical and Molecular Research
- Polyamine Metabolism and Applications
- Microbial Community Ecology and Physiology
- Thermoregulation and physiological responses
- Microbial bioremediation and biosurfactants
- Thermal Regulation in Medicine
- Hydrogen Storage and Materials
- Enzyme Catalysis and Immobilization
Max Planck Institute for Terrestrial Microbiology
2011-2021
Philipps University of Marburg
2000-2018
Max Planck Society
2003-2015
Weatherford College
2011
ETH Zurich
2003-2009
University of Oxford
2008-2009
Max Planck Institute of Biophysics
1997-2008
Max Planck Institute for Marine Microbiology
2008
European Molecular Biology Laboratory
2008
University of Illinois Urbana-Champaign
2008
Biological formation and consumption of molecular hydrogen (H 2 ) are catalyzed by hydrogenases, which three phylogenetically unrelated types known: [NiFe]-hydrogenases, [FeFe]-hydrogenases, [Fe]-hydrogenase. We present a crystal structure [Fe]-hydrogenase at 1.75 angstrom resolution, showing mononuclear iron coordinated the sulfur cysteine 176, two carbon monoxide (CO) molecules, sp -hybridized nitrogen 2-pyridinol compound with back-bonding properties similar to those cyanide. The...
Methyl–coenzyme M reductase (MCR), the enzyme responsible for microbial formation of methane, is a 300-kilodalton protein organized as hexamer in an α 2 β γ arrangement. The crystal structure from Methanobacterium thermoautotrophicum , determined at 1.45 angstrom resolution inactive state MCR ox1-silent reveals that two molecules nickel porphinoid coenzyme F 430 are embedded between subunits α, α′, β, and β′, γ′, forming identical active sites. Each site accessible substrate methyl–coenzyme...
Clostridium kluyveri is unique among the clostridia; it grows anaerobically on ethanol and acetate as sole energy sources. Fermentation products are butyrate, caproate, H2. We report here genome sequence of C. kluyveri, which revealed new insights into metabolic capabilities this well studied organism. A membrane-bound energy-converting NADH:ferredoxin oxidoreductase (RnfCDGEAB) a cytoplasmic butyryl-CoA dehydrogenase complex (Bcd/EtfAB) coupling reduction crotonyl-CoA to with ferredoxin...
Cell extracts of butyrate-forming clostridia have been shown to catalyze acetyl-coenzyme A (acetyl-CoA)- and ferredoxin-dependent formation H2 from NADH. It has proposed that these bacteria contain an NADH:ferredoxin oxidoreductase which is allosterically regulated by acetyl-CoA. We report here ferredoxin reduction with NADH in cell Clostridium kluyveri catalyzed the butyryl-CoA dehydrogenase/Etf complex acetyl-CoA dependence previously observed due fact via crotonyl-CoA butyryl-CoA. The...
In methanogenic archaea growing on H 2 and CO the first step in methanogenesis is ferredoxin-dependent endergonic reduction of with to formylmethanofuran last exergonic heterodisulfide CoM-S-S-CoB coenzyme M (CoM-SH) B (CoB-SH). We recently proposed that hydrogenotrophic methanogens two reactions are energetically coupled via cytoplasmic MvhADG/HdrABC complex. It reported here purified complex from Methanothermobacter marburgensis catalyzes CoM-S-S-CoB-dependent ferredoxin . Per mole added,...
Different species of methanogenic bacteria growing on CO 2 and H were shown to remove added the gas phase. Rates up 0.2 μmol depleted/min per 10 ml culture containing approximately 7 mg cells (wet weight) observed. Methanobacterium thermoautotrophicum was selected for further study based its ability grow rapidly a completely mineral medium. This used as sole energy source by disproportionating CH 4 according following equation: 4CO + 2H O → 1CH 3CO . However, growth slight, rate only 1% that...
Synthesis of acetate from carbon dioxide and molecular hydrogen is considered to be the first assimilation pathway on earth. It combines fixation into acetyl-CoA with production ATP via an energized cell membrane. How coupled net synthesis has been enigma. The anaerobic, acetogenic bacterium Acetobacterium woodii uses ancient version this without cytochromes quinones. generates a sodium ion potential across membrane by sodium-motive ferredoxin:NAD oxidoreductase (Rnf). genome sequence A....
Flavin-based electron bifurcation is a recently discovered mechanism of coupling endergonic to exergonic redox reactions in the cytoplasm anaerobic bacteria and archaea. Among five electron-bifurcating enzyme complexes characterized date, one heteromeric ferredoxin- NAD-dependent [FeFe]-hydrogenase. We report here novel [FeFe]-hydrogenase that NADP rather than NAD specific forms complex with formate dehydrogenase. The was found high concentrations (6% cytoplasmic proteins) acetogenic...
Most acetogens can reduce CO2 with H2 to acetic acid via the Wood-Ljungdahl pathway, in which ATP required for formate activation is regenerated acetate kinase reaction. However, a few acetogens, such as Clostridium autoethanogenum, ljungdahlii, and ragsdalei, also form large amounts of ethanol from H2. How these anaerobes growth pH optimum near 5 conserve energy has remained elusive. We investigated this question by determining specific activities cofactor specificities all relevant...