Sophie ABBY
21/05/2025 10:00 - 11:30
Emplacement: Salle Oléron
In this seminar, I will present a multi-scale view of the evolution and diversification of enzymes and biosynthetic pathways. To this end, I will use the perspective of the isoprenoid quinones production in Bacteria. Isoprenoid quinones are lipids that shuttle electrons in electron transfer chains: they are therefore at the heart of cellular energy production via respiration and photosynthesis. Despite their essentiality and overall conservation, quinone biosynthetic pathways endured a variety of evolutionary events that led to their diversification that we aim to unravel. Our first endeavour is thus to produce highly reliable genomic annotations of the enzymes and proteins involved, and sometimes to propose novel proteins for missing steps in the pathways. To this end, we integrate the information of genome context conservation, taxonomic distribution, phylogenetic grouping, and experimental validation. The study of quinone pathways illustrates how enzymes from a same protein family can evolve distinct yet close functions through gene duplications 1, but also how biosynthetic pathways can evolve variants while conserving the same precursor and end-product 1,2. The study of the quinone repertoire across the bacterial phylum Pseudomonadota enabled us to infer how its dynamics involved genetic transfers and losses of entire quinone pathways, and how this dynamics likely accompanied the metabolic transition between oxic and anoxic environments 3. Finally, I’ll show how the discovery of novel respiratory quinones can help understand the early diversification of bacterial metabolisms 4.
References
[1] Kazemzadeh K, Pelosi L, Chenal C, et al. Diversification of ubiquinone biosynthesis via gene duplications, transfers, losses, and parallel evolution. Battistuzzi FU, ed. Molecular Biology and Evolution. Published online October 3, 2023:msad219. https://doi.org/10.1093/molbev/msad219
[2] Pelosi L, Vo CDT, Abby SS, et al. Ubiquinone Biosynthesis over the Entire O 2 Range: Characterization of a Conserved O 2 -Independent Pathway. Newman DK, ed. mBio. 2019;10(4). https://doi.org/10.1128/mBio.01319-19
[3] Chobert SC, Roger-Margueritat M, Flandrin L, et al. Dynamic quinone repertoire accompanied the diversification of energy metabolism in Pseudomonadota. The ISME Journal. 2025;19(1):wrae253. https://doi.org/10.1093/ismejo/wrae253
[4] Elling FJ, Pierrel F, Chobert SC, et al. A novel quinone biosynthetic pathway illuminates the evolution of aerobic metabolism. Proc Natl Acad Sci USA. 2025;122(8):e2421994122. https://doi.org/10.1073/pnas.2421994122
For internal attendees.