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A systematic exploration of bacterial form I rubisco maximal carboxylation rates.

A systematic exploration of bacterial form I rubisco maximal carboxylation rates.

Authors :
de Pins, Benoit
Greenspoon, Lior
Bar-On, Yinon M
Shamshoum, Melina
Ben-Nissan, Roee
Milshtein, Eliya
Davidi, Dan
Sharon, Itai
Mueller-Cajar, Oliver
Noor, Elad
Milo, Ron
Source :
EMBO Journal. Jul2024, Vol. 43 Issue 14, p3072-3083. 12p.
Publication Year :
2024

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 CO2 concentrating mechanism correlates with faster rubiscos with a median fivefold 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. Synopsis: Form I rubisco, known for its slow kinetics in plants and algae, exhibits a great unexplored diversity in autotrophic bacteria. This article represents the first large-scale survey of bacterial form I rubisco kinetics and reveals unifying features of fast carboxylating rubiscos. Over 100 homologs were systematically screened, spanning the wide genetic diversity of form I rubisco enzymes across a variety of ecological niches and metabolic profiles. Phototrophy and carboxysome association are correlated with fast-carboxylating rubiscos. α-cyanobacteria emerges as the bacterial clade expressing the fastest form I rubiscos on Earth. Bacterial rubisco enzymes associated with carboxysomes have the fastest CO2-fixing rates. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
02614189
Volume :
43
Issue :
14
Database :
Academic Search Index
Journal :
EMBO Journal
Publication Type :
Academic Journal
Accession number :
178469273
Full Text :
https://doi.org/10.1038/s44318-024-00119-z