Systematic exploration of prokaryotic form I rubisco maximal carboxylation rates

de Pins, B.; Greenspoon, L.; Bar-On, Y. M.; Shamshoum, M.; Ben-Nissan, R.; Milshtein, E.; Davidi, D.; Sharon, I.; Mueller-Cajar, O.; Noor, E.; Milo, R.

doi:10.1101/2023.07.27.550689

bioRxiv · 10.1101/2023.07.27.550689

Systematic exploration of prokaryotic form I rubisco maximal carboxylation rates

de Pins, B.·Greenspoon, L.·Bar-On, Y. M.·Shamshoum, M.·Ben-Nissan, R.·Milshtein, E.·Davidi, D.·Sharon, I.·Mueller-Cajar, O.·Noor, E.·Milo, R.

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Abstract

Autotrophy is the basis for complex life on Earth. Central to this process is rubisco - the enzyme that catalyzes almost all carbon fixation on the planet. Yet, with only a small fraction of rubisco diversity kinetically characterized so far, the underlying biological factors driving the evolution of fast rubiscos in nature remain unclear. We conducted a high-throughput kinetic characterization of over 100 bacterial form I rubiscos, the most ubiquitous group of rubisco sequences in nature, to uncover the determinants of rubiscos carboxylation velocity. We show that the presence of a carboxysome CO2 concentrating mechanism correlates with faster rubiscos with a median 5-fold higher rate. In contrast to prior studies, we find that rubiscos originating from -cyanobacteria exhibit the highest carboxylation rates among form I enzymes ({approx}10 s-1 median versus <7 s-1 in other groups). Our study systematically reveals biological and environmental properties associated with kinetic variation across rubiscos from nature.

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de Pins, B., Greenspoon, L., Bar-On, Y. M., Shamshoum, M., Ben-Nissan, R., Milshtein, E., Davidi, D., Sharon, I., Mueller-Cajar, O., Noor, E., Milo, R.. 2023-07-27. Systematic exploration of prokaryotic form I rubisco maximal carboxylation rates. https://doi.org/10.1101/2023.07.27.550689

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