Super excited to share my 1st first-author publication out today in @ScienceMagazine, in which we resurrect billion-year-old enzymes to study the evolution of Rubisco. Let me tell you how a 100 amino acid protein facilitated the rise of oxygenic life.

RT @AdrianBunzel: 🌍 Exciting news! This summer, my group joins @mpi_marburg to create photoenzymes for solar energy conversion & carbon cap….

Check out Beau‘s sick PhD work!! Finally out for the world to read.

RT @BDronsella: Glad to see my main PhD project finally out @NatureMicrobiol We show for the first time that a synt….

RT @RebeleinLab: Congrats to @Leo_Ernst_2 for successfully defending his PhD thesis @mpi_marburg !🎊🍾🎉🥳 The first doctor from the Rebelein….

RT @TListerChem: The story of how I developed the first biocatalysts for convergent and stereoselective SNAr chemistry is out now in @Natur….

RT @GreenGroupMIB: Delighted to announce that 'Engineered enzymes for enantioselective nucleophilic aromatic substitutions' is out now in N….

RT @RebeleinLab: Two exciting papers about the the protection of nitrogenases from O2 by the ferredoxin Shethna protein II from the Tezcan….

RT @SendkerFL: Happy to share our story on evolution of protein quaternary structure!.We discover an astounding variation in assembly acros….

lets gooooo - congratz Johannes!.

Check this out!! highly recommend being in Tobi’s lab - so much scientific freedom, resources, and career support!.

RT @erblabs: We are looking for a postdoc - in a project on a UbiD like (de)carboxylase!

RT @mirbachh: Lets talk about #acetyl-CoA! As central molecule in C1 metabolism, the efficiency of its assimilation determines yields. Read….

For some more fun biochemistry (& a lot of cool evolutionary implications) I recommend that you check out the publication and/or message me! . A huge thanks to my mentors @KaHochberg and @erblabs, as well as all co-authors, who have been crucial in getting this work done.

Focusing on substitutions that occurred in such regions, we identified historical changes that drastically reduced Rubisco’s activity but whose negative effect is buffered by the presence of the SSU.

Inspired by NMR-guided directed evolution, we used hydrogen-deuterium exchange experiments to identify structural features of Rubisco that change their deuterium uptake behavior (which is indicative of altered dynamics) upon inhibitor binding.

Intriguingly, some Rubisco variants we created were soluble and octameric, yet catalytically inactive without the SSU. This suggested that historical substitutions can render catalysis SSU-dependent. To find such substitutions, we focused on active site responsive regions.

This suggested a direct link between Rubisco’s active site and the octamer interface. Indeed, addition of tight-binding inhibitors reconstituted oligomerization into octamers (see figure above) and pre-incubating Rubisco with a weak-binding inhibitor recovered activity in assays.

We found that the Rubiscos we worked with could not efficiently catalyze their reaction when they did not form octamers. This contrasts the many Rubiscos that exist as simple dimers of large subunits. But how can we prove that the loss of oligomerization really was the cause?.

We found that historical substitutions at the dimer-dimer interface made octamer formation SSU-dependent. The SSU bridges adjacent dimers, which stabilizes the dimer-dimer interface. This allows evolution to explore a less stable interface. But why is octamer formation important?

We were interested in the biochemical mechanisms by which Rubisco started to depend on the SSU. To investigate these, we introduced historical substitutions into a Rubisco that could bind the new subunit but did not yet need it.