Reductases of Gram-positive Anaerobes
 
 

The lab of Kathrin Makdessi
 

contact projects members of the group publications

 

PROJECTS 1. Role of tungsten in the metabolism of Eubacterium acidaminophilum Eubacterium acidaminophilum is a Gram-positive, anaerobic microorganism that degrades amino acids via Stickland reaction. From this organism three tungsten-containing enzymes have been isolated and characterized: formate dehydrogenase I, formate dehydrogenase II, and an aldehyde oxidoreductase. Tungsten is a rare element and only few microorganisms, mainly thermophiles and hyperthermophiles, use this metal-ion in their metabolism. E. acidaminophilum is exceptional being a mesophile. Recent studies revealed that E. acidaminophilum possesses a tungstate-specific uptake system, which belongs to the ABC-transporter family. The extracellular solute-binding protein (TupA) is tungstate specific and is able to discriminate between tungstate and molybdate. This finding raises the question about the molecular mechanism of the distinction. Furthermore, this bacterium contains a cytoplasmic molybdate/tungstate-binding protein (Mop), that belongs to the molbindin family proteins, which have been implicated in molybdenum storage and homeostasis. Our research is directed at the overall tungsten metabolism of this organism and includes: the tungstate uptake and the characterization of the TupA protein and related proteins from other organisms by X-ray analysis. the role of the Mop protein the special metabolic function of tungsten-containing enzymes   2. D-proline reductase of Clostridium sticklandii D-proline reductase from Clostridium sticklandii catalyzes the reductive ring cleavage of D-proline to 5-aminovalerate. It contains a substrate activating pyruvoyl group and a catalytic active selenocysteine. The pyruvoyl group is formed after cleavage of a proprotein from a cysteine residue and thus these enzymes are distinct from other pyruvoyl-containing enzymes where the pyruvoyl group is formed from a serine residue. This project aims at the biochemical characterization of this enzyme in comparison to glycine reductase and the regulation of gene transcription. MEMBERS OF THE GROUP Kathrin Makdessi, PhD Phone:  +49 345 55 26353  Fax:   +49 345 55 27010 E-mail: kathrin.makdessi@mikrobiologie.uni-halle.de   David Rauh, PhD student Room 206, Phone:  +49 345 55 26358 E-mail: david.rauh@mikrobiologie.uni-halle.de   Karola Otto, technical assistant Room 206, Phone:  +49 345 55 26358   Iljana Mögel, diploma student Room 206, Phone:  +49 345 55 26358 E-mail:iljana.moegel@mikrobiologie.uni-halle.de   PUBLICATIONS Makdessi, K., Fritsche, K., Pich, A., Andreesen, J. R. (2004): Identification and characterization of the cytoplasmic tungstate/molybdate-binding protein (Mop) from Eubacterium acidaminophilum. Arch Microbiol 81: 45-51 Rauh, D., Graentzdoerffer, A., Granderath, K., Andreesen, J. R., Pich, A. (2004): Tungsten-containing aldehyde oxidoreductase of Eubacterium acidaminophilum. Eur J Biochem 271: 212-219 Graentzdoerffer, A., Rauh, D., Pich, A., Andreesen, J. R. (2003): Molecular and biochemical characterization of two tungsten-and selenium-containing formate dehydrogenases from Eubacterium acidaminophilum that are associated with components of an iron-only hydrogenase. Arch Microbiol 179: 116-130 Makdessi, K., Andreesen, J. R., Pich, A. (2001): Tungstate Uptake by a highly specific ABC transporter in Eubacterium acidaminophilum. J Biol Chem 276: 24557-64 Graentzdoerffer, A., Pich, A., Andreesen, J. R. (2001): Molecular analysis of the grd operon coding for genes of the glycine reductase and of the thioredoxin system from Clostridium sticklandii. Arch Microbiol 175: 8-18 Andreas Pich, Kathrin Makdessi, David Rauh, Andrea Gräntzdörffer and Jan. R. Andreesen (2001): Tungstate Uptake by a highly specific ABC transporter in Eubacterium acidaminophilum. Poster in: Molybdenum and Tungsten Enzymes, Gordon Research Conference. 1-6 July 2001, Queen's College, Oxford, England Bednarski, B., Andreesen J., R., Pich, A. (2001): In vitro processing of the proproteins GrdE of protein B of glycine reductase and PrdA of D-proline reductase from Clostridium sticklandii: formation of a pyruvoyl group from a cysteine residue. Eur J Biochem 268: 3538-44 Kabisch, U. C., Gräntzdörffer, A., Schierhorn, A., Rücknagel, K. P., Andreesen, J. R., Pich, A. (1999): Identification of D-proline reductase from Clostridium sticklandii as a selenoenzyme and indications for a catalytically active pyruvoyl group derived from a cysteine residue by cleavage of a proprotein. J Biol Chem 274: 8445-54