Ms. Mariana Grieben

Photo of Mariana  Grieben

Dr. Mariana Grieben

Groth Group
Biochemical Plant Physiology
Heinrich Heine University
Universitätsstr.1
Building: 26.02
Floor/Room: O1
40225 Düsseldorf
Phone +49 211 81-15232

Mini Academic CV

University degrees:

First degree or intermediate examination:

  • BSc(Biochemistry), 2006, Heinrich-Heine University, Düsseldorf, Germany

Second degree and/or intermediate examination:

  • MSc(Biochemistry), 2008, Heinrich-Heine University, Düsseldorf, Germany

Further degrees and/or interemediate examinations:

  • Vordiplom(Landscape Ecology), 2004, Westfälische Wilhelms University, Münster, Germany

BioStruct PhD project

Structure and regulation of chloroplast F0F1 ATP synthase
F0F1-ATP synthases found in bacteria, mitochondria and in the photosynthetic membranes of chloroplasts or cyanobacteria catalyze the formation of ATP from ADP and inorganic phosphate at the expense of a transmembrane proton gradient. The F0F1 holoenzyme consists of the membrane-embedded F0-domain and the interconnected soluble F1-domain. The energy of the transmembrane proton gradient is used by F0 to translocate protons, which is coupled to ATP synthesis via a rotary catalytic mechanism located on F1. In contrast to bacterial and mitochondrial F-ATPases chloroplast F1 is a latent ATPase requiring activation before catalytic turnover can take place. The activation is regulated via the redox state of two cysteines in the gamma-subunit. Detailed information on the molecular mechanism of this regulation is anticipated from high resolution structures of the oxidized and the reduced F1-complex from the thermophilic cyanobacterium Thermosynechococcus elonagatus BP-1. The structural basis of the redox regulation of photosynthetic F ATPases will be further addressed by structural studies on the isolated, recombinant spinach chloroplast gamma-subunit. We intend to crystallize the isolated gamma-subunit in the reduced and oxidized form as well as a redox-complex of gamma with the natural redox-compound thioredoxin. The second main objective of the project is to solve the structure of the intact F0F1 holoenzyme. Previous structural studies on F0F1 have shown that the F0-F1 contact is fragile. In order to stabilize the F0F1 interaction we will construct chimeric enzymes containing the membrane embedded F0 from Escherichia coli and the catalytic F1 from Thermo synechococcus which are amenable to cysteine-crosslinking.

Supervisors

Topic Supervisor:

undefinedProf. Dr. Georg Groth, Institute for Biochemical Plant Physiology, Heinrich Heine University Duesseldorf, Groth Group

Complementary Supervisor:

undefinedProf. Lutz Schmitt, Institute for Biochemistry, Heinrich Heine University Duesseldorf, Schmitt Group

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