PhD ceremony Ms. M.T. Webber-Birungi: Structural revelations of photosynthesis' membrane protein complexes

PhD ceremony: Ms. M.T. Webber-Birungi, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Structural revelations of photosynthesis' membrane protein complexes

Promotor(s): prof. E.J. Boekema

Faculty: Mathematics and Natural Sciences

The diversity of the photosynthesis proteins due to evolution upon adaptation and exploitability is intriguing for researchers from all fields of science to understand aspects of structural diversity, function and dynamics. The work of Mariam T. Webber-Birungi is highly complementary and has been carried out in multidisciplinary collaborations to get more impact for understanding the photosynthesis systems that evolved early or later. The results of which can be integrated into applied technology.

Important about photosynthesis systems are the high-energy conversion efficiency and oxygen evolution besides hydrogen generation by some organisms like cyanobacteria. These features are precious global demands for efficient sun utilizing devices, environmental concerns and current economics of alternative energy source to fossil fuel depletion.

Photosynthetic organisms appeared early in evolution and their photosynthetic apparatus has evolved along. The first bacteria carried out only anoxygenic photosynthesis catalyzed by one type of reaction center, type I or II, which somehow came together in cyanobacteria, and evolved into photosystems I and II. This was an evolutionary step that enabled cyanobacteria to carry out oxygenic photosynthesis. The photosystems have the unique capacity to perform and fix energy in a process where water splitting and oxygen evolution takes place, providing planet Earth with an essential molecule for development of life, i.e. Oxygen. Throughout evolution, primordial organisms became more complex upon colonizing diverse environments resulting into the current day sophisticated systems. Nevertheless, the photosystems have preserved their vital mechanisms of sunlight conversion with PSI at almost 100% efficiency, and PSII’s unique water splitting property.