Graduate Students Mini-Symposium II 2025

13:15 h Dennis Wiens - MPRG Hochberg

Evolution of Rubisco’s chaperone dependence

Molecular chaperones assist the folding and assembly of proteins, but little is known about their evolutionary origins. Rubisco, the enzyme responsible for carbon fixation in photosynthesis, is a heteromeric protein complex and serves as a model system to study chaperone evolution. Despite high sequence similarity, Rubisco from higher plants requires much more extensive chaperone assistance during assembly of the complex than cyanobacterial Rubisco. We seek to answer why and how this complexity arose using ancestral sequence reconstruction. We could previously show that cyanobacterial chaperones increase assembly efficiency. Through biochemical characterization and comparison of ancestral Rubisco proteins we were able to show that dependence on additional chaperones emerged early in the evolution of plants. We verified this result by the first reconstitution of a basal Streptophyte Rubisco. We further show that dependence can be reversed by a few historical substitutions. These substitutions can also influence chaperone dependence in extant Rubisco proteins. With these insights we can possibly engineer chaperone-independent Rubisco and gain a fundamental understanding about the evolutionary and structural mechanisms governing chaperone dependence.

13:45 Adrian Podolski - AG Bode
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14:15 Leonie Schenk - AG Bode
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