Summary: Pyrenoids are chloroplast microcompartments that enhance Rubisco-based CO2 fixation in algae and hornworts. How pyrenoids assemble, function and evolved convergently across lineages is discus...

Despite substantial research into the architecture and biology of the pyrenoid, the fundamental biochemistry of these organelles remains unclear. In particular, the mechanism of carboxylation enhancem...

This study shows that the structural protein essential pyrenoid component 1 (EPYC1) and the enzyme Rubisco are sufficient to assemble into pyrenoid-like structures that are functionally active and sho...

This study shows that the structural protein essential pyrenoid component 1 (EPYC1) and the enzyme Rubisco are sufficient to assemble into pyrenoid-like structures that are functionally active and sho...

This study shows that the structural protein essential pyrenoid component 1 (EPYC1) and the enzyme Rubisco are sufficient to assemble into pyrenoid-like structures that are functionally active and sho...

Barrett, J. et al. A promiscuous mechanism to phase separate eukaryotic carbon fixation in the green lineage. Nat. Plants 10, 1801–1813 (2024). This paper describes a range of different IDPs that form pyrenoids. Freeman Rosenzweig, E. S. et al. The eukaryotic CO2-concentrating organelle is liquid-like and exhibits dynamic reorganization. Cell 171, 148–162.e19 (2017). This paper is, to our knowledge, the first to show the condensate-like behaviour of the pyrenoid. Shimakawa, G. et al. Diatom pyrenoids are encased in a protein shell that enables efficient CO2 fixation. Cell 187, 5919–5934.e19 (2024). This article reports that pyrenoid architecture differs between diatoms and green algae. He, S. et al. The structural basis of Rubisco phase separation in the pyrenoid. Nat. Plants 6, 1480–1490 (2020). This paper reports the in vitro reconstitution, interaction motifs and structure of the pyrenoid matrix...

This study shows that the structural protein essential pyrenoid component 1 (EPYC1) and the enzyme Rubisco are sufficient to assemble into pyrenoid-like structures that are functionally active and sho...

This study shows that the structural protein essential pyrenoid component 1 (EPYC1) and the enzyme Rubisco are sufficient to assemble into pyrenoid-like structures that are functionally active and sho...

We first screened the capability of diverse IDPs for liquid–liquid phase separation (LLPS) of Rubisco. To that end, we selected the well-studied form II Rubisco from Rhodospirillum rubrum (CbbM) as a target. CbbM is a simple bacterial Rubisco that consists only of a large subunit, which exists as a homodimer and can be produced soluble at high protein concentrations. Although CbbM did not co-evolve with EPYC1CR (or any other IDP), we reasoned that the enzyme provides a robust platform to study the effects of IDP fusions on Rubisco-based CO2 fixation. Using CbbM as a target, we fused a library of IDPs3,9,29,30,31,32,33,34,35,36 to the protein’s carboxy terminus and to its C and amino termini (Fig. 2a,b and Supplementary Table 1). This library contained EPYC1 from C. reinhardtii (EPYC1CR), as well as nine other IDPs that had previously shown condensate formation as individual proteins or when fused to other target enzymes. When tested between concentrations of 1 and 20 µM, only EPYC1CR initiated functional and stable condensates with its non-natural target CbbM (Fig. 2b and Supplementary Figs. 1 and 2). All other IDPs—except for a few IDPs that aggregated—showed no phase-separating effect on CbbM (Supplementary Figs. 2 and 3) but seemed also...

In many algae, photosynthesis is boosted by biophysical CO2-concentrating mechanisms, which pack the CO2-fixing enzyme Rubisco into liquid-like organelles called pyrenoids. Engineering C3 crops with a...

Installing algal pyrenoids or cyanobacterial carboxysomes into plants to enhance photosynthetic efficiency remains a formidable challenge. Here, the authors report the construction of CO2-fixing nanoc...

Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO2 fixation. Diatoms fix up to 20% of global CO2, …