Dr. Dmitry Shvarev, University of Osnabrück

Chlorophyll is a central pigment of photosynthesis and essential for life on Earth. Although the multistep process of chlorophyll biosynthesis has been well characterized biochemically and is highly conserved among photosynthetic organisms, including cyanobacteria, algae and plants, its spatial and structural organization remains poorly understood. This is largely due to the transient and dynamic nature of the enzyme complexes involved, many of which are membrane-associated. However, recent advances in structural biology, particularly in cryogenic electron microscopy (cryo-EM), have opened new opportunities to overcome these challenges and investigate these systems at high resolution.

In my group, we combine biochemical approaches and cryo-EM to study chlorophyll biosynthesis and related processes in cyanobacteria. In this talk, I will highlight our recent work on the architecture of key enzymes in the pathway. I will focus on magnesium chelatase, which catalyzes the first committed step of chlorophyll biosynthesis, and chlorophyll synthase, the terminal enzyme of the pathway. I will present insights into subunit organization and ligand-induced conformational changes and propose models for the respective catalytic reactions. Finally, I will discuss future perspectives in structural studies of chlorophyll biosynthesis and related processes, and outline our laboratory's research directions in this area.