Bacteria contain the simplest photosynthetic machineries found in nature. Higher organisms like algae and plants practice photosynthesis in a more elaborate but principally similar manner as bacteria. But even for its simplicity, the bacterial photosynthetic unit is not without its unsolved mysteries. Take, for example, the crucial photosynthetic core complex, which performs light absorption and the initial processing of the light energy. In certain bacterial species, the core complex are each ring-shaped singlets, but in some other bacterias they can be 8-shaped doublets, formed by the association of two ring-shaped core complexes. The question arises: What holds doublets together. It turned out that doublets arise when bacteria bacterial contain two copies, i.e., twins, of an additional small protein called PufX. Recently, computational biologists and biochemists have come together to study PufX from different bacteria. They found an interesting trend showing that bacterial species with PufX that associates with another PufX protein also contain core complexes that form 8-shaped doublets. On the other hand, bacteria whose PufX is incapable of associating with another PufX have only singlets of ring-shaped core complexes. These new results resonate with a proposed role of PufX as the protein that holds two core complexes together to form 8-shaped doublets. Bacteria with PufX that cannot perform this role therefore only have singlets of ring-shaped core complexes. The needed simulations were done with NAMD. More details can be found on our photosynthetic core complex website and in a previous highlight on PufX.