One of the key events in early cellular evolution is the separation of the last universal common ancestor (LUCA) into Archaea and Bacteria. Although both are prokaryotes, these two domains of life differ in many ways, including the architecture of their lipid membranes. The textbook teaches us bacterial lipids exist of fatty acid lipid tails, that are ester-linked to the sn-glycerol 3-phosphate lipid backbone. On the other hand, archaeal lipids are made up of isoprenoid lipidtails, that are ether-linked to the stereochemical different sn-glycerol 1-phosphate backbone. This segregation, part of the
so-called “Lipid divide”, is however not as strict as long thought. Recent literature reports on the presence of both glycerol-phosphate backbones in the lipids from Bacillus subtilis. Here, we explored to what extent the observed stereochemical variety of the bacterial lipids can be attributed to their general biosynthesis. In short, the bacterial acyl-transferases that attach the lipid tails to the glycerol
phosphate backbone, show no clear preference to the stereochemistry. In other words, the variety in lipid backbone is an intrinsic part of bacterial lipid biogenesis, suggesting a less strict role for stereochemistry in the lipid divide.