The rise and the fall of strange chemistries in ribosome evolution from microbes to humans

That ribosomes join α-amino acids to make proteins is textbook knowledge. Much less is known that the assembly and the function of the ribosomes themselves critically depend on an unusual β-amino acid residue. Here, we will discuss the how, the why and the what if of this ancestral modification that continues to be essential for protein synthesis in bacteria, archaea, and eukaryotes alike.