Biosciences and Biotechnology Institute of Aix-Marseille
A unique feature of photosynthetic organisms is their capacity to use solar energy to generate complex organic compounds from simple inorganic molecules. Photosystem II and Photosystem I are important enzymes where light absorption and the first steps of chemical energy conversion take place. Since plants have a sessile life style, these photosystems need to cope very efficiently with fast environmental changes such as fluctuations in the incident light and its quality. We have a pluridisciplinary approach using biochemistry, molecular biology, steady state and time resolved spectroscopic methods to better understand the structure and function of these photosystems and to elucidate their structural adaptations and defence mechanisms to stress conditions such as excess light. For this we are using the different photosynthetic models of the laboratory (Arabidopsis,
Physcomitrella and photosynthetic bacteria).
Photosytem II purification by ultracentrifugation of solubilized membranes in a sucrose gradient. Photosystem II supercomplexes with different antenna size migrate at different positions and have been visualized by electron microscopy techniques. A structural model of the largest PSII supercomplex is also shown. électronique - Crédit : Stefano CAFFARRI/ AMU
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.