Bottom-up reconstruction of synthetic pyrenoids provides insights into the mechanisms and evolution of carbon concentration by EPYC1 proteins.

Synthetic pyrenoids formed by ancestral and modern EPYC1 sequences achieve functional carbon-concentrating mechanisms with enhanced carboxylation rates, revealing key evolutionary insights.

• Why it matters: Understanding how simple condensates evolved into complex organelles like pyrenoids is crucial for advancing knowledge of cellular carbon fixation and improving photosynthetic efficiency.
• What they did: Researchers used a bottom-up approach to test over 1000 EPYC1 sequence variants across phylogenetic diversity, demonstrating their ability to induce phase separation of Rubisco into synthetic pyrenoids.
• The result: The findings show that these synthetic pyrenoids primarily boost CO 2 fixation through increased carboxylation rates, providing new perspectives on the evolution and design of efficient CCMs.