Genomics, Proteomics, Bioinformatics

Photosynthesis on Earth: Evolution Of Increased Complexity And Specificity At The Dawn Of Form I Rubiscos

By Keith Cowing
Press Release
Pubmed
October 15, 2022
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Photosynthesis on Earth: Evolution Of Increased Complexity And Specificity At The Dawn Of Form I Rubiscos
Structural characterization of AncL+7 and AncL+7 e170N. Alignment of a dimer in AncL+7 co-crystallized without (purple) or with (pink) AncSSU (rose) and CABP, overlaid with an alignment of a dimer in AncL+7 e170N co-crystallized without (teal) or with (orange) AncSSU (beige) and CABP. The respective dimers align with an average rmsd of <0.3 Γ… and show no major re-arrangements. Science

The evolution of ribulose-1,5-bisphosphate carboxylase/oxygenases (Rubiscos) that discriminate strongly between their substrate carbon dioxide and the undesired side substrate dioxygen was an important event for photosynthetic organisms adapting to an oxygenated environment.

We use ancestral sequence reconstruction to recapitulate this event. We show that Rubisco increased its specificity and carboxylation efficiency through the gain of an accessory subunit before atmospheric oxygen was present. Using structural and biochemical approaches, we retrace how this subunit was gained and became essential.

Our work illuminates the emergence of an adaptation to rising ambient oxygen levels, provides a template for investigating the function of interactions that have remained elusive because of their essentiality, and sheds light on the determinants of specificity in Rubisco.

Luca Schulz 1, Zhijun Guo 2, Jan Zarzycki 1, Wieland Steinchen 3 4, Jan M Schuller 3 4, Thomas Heimerl 3 5, Simone Prinz 6, Oliver Mueller-Cajar 2, Tobias J Erb 1 3, Georg K A Hochberg 3 4 7

PMID: 36227987 DOI: 10.1126/science.abq1416
Pubmed

Evolution of increased complexity and specificity at the dawn of form I Rubiscos, Science

Astrobiology, genomics,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»