2023/07/27 by Benoit de Pins, Lior Greenspoon, Yinon M. Bar‐On +8 · 1 voice
Environmental Science · Biochemistry, Genetics and Molecular Biology · #Microbial Community Ecology and Physiology #Metabolomics and Mass Spectrometry Studies #Photosynthetic Processes and Mechanisms
paper · pdf · doi:10.1101/2023.07.27.550689
openalex publication_date 2023/07/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/14
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 rubisco’s carboxylation velocity. We show that the presence of a carboxysome CO 2 concentrating mechanism correlates with faster rubiscos with a median 5-fold higher rate. In contrast to prior studies, we find that rubiscos originating from α-cyanobacteria exhibit the highest carboxylation rates among form I enzymes (≈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.