One heterodimeric lineage becomes the ancestor to the chlorophyll and bacteriochlorophyll synthesis enzymes now only found in bacteria; the other lineage becomes nitrogenase in a methanogenic ancestor. It has interesting implications depending on various plausible scenarios 😀

This is my reading then. An ancestral homodimeric reductase in tetrapyrrole biosynthesis diverges, one lineage becomes CfbD in archaeal methanogenesis, the other duplicates. The new evolving heterodimers, still involved in tetrapyrrole biosynthesis diverges into two new lineages...

I just see the paper! Wow, this is indeed fascinating. You guys suggest that CbfD is ancestral to all other Nif proteins, right? Then would you say that tetrapyrrole biosenthesis is the ancestral function of this family of enzymes all in all? 😊

I’m a photosynthesis researcher! I work on resolving the evolution of photosynthesis and on evolving new types of photosynthesis. I might be able to help