Molecular mechanism of protecting plants from high intensity sunlight: studying Light Harvesting proteins using a combination of advanced electron microscopy and fluorescence methods

Understanding the biophysics of photosynthesis could provide clues to developing the next generation of crops. Light-Harvesting Complex II (LHCII) is the main protein in plants that absorbs solar photons and channels energy to where it is needed. LHCII is estimated to be the most abundant membrane protein on Earth and is essential for efficient photosynthesis, yet, its crucial role in “photoprotection” has an unknown mechanism. This project will use cutting-edge biochemical and biophysical techniques and our world-class microscopy facilities to study how LHCII can switch between different states. Project aims: (1) to determine a high-resolution structure of the LHCII in the “light-harvesting” vs “protected” state, (2) to quantify what triggers photoprotection in LHCII by analyzing “model membranes”, (3) to correlate changes in molecular structure with changes in function towards a definitive mechanism. To do this, LHCII will be biochemically purified and characterized with state-of-the-art fluorescence techniques in parallel with single-particle cryo electron microscopy. You will use LHCII either isolated in detergent suspension or incorporated within nanoscale lipid bilayers to test the effect of lipids. This will provide insight into the biophysical basis of photosynthetic processes crucial for life on Earth but poorly understood.