Tailocin Factory Cells

Tailocins are phage tail-like bacteriocins that kill bacterial cells. Their production by bacteria under stress conditions and release into the environment are considered bacterial altruism, as a small part of the population does that for the benefit of the rest. While this phenomenon was demonstrated in different bacteria, it remains unclear how a critical mass of tailocins is achieved by a small number of producer cells, that succeeds to pose an impact on the ecological niche. In this study we demonstrate that 1% of the bacteria within the population turn themselves into "tailocin factories", that produce and orderly package thousands of tailocins per cell, that are ready to be launched to the environment. In these cells, the tailocins are aligned and stored in a highly ordered liquid crystalline structures, that consist of multiple layers of tailocins lining head-to-tail, which occupy a substantial volume of the bacterial cell. Using transmission electron microscopy and cryo-electron tomography, we provide a detailed structure of these tailocin armouries, and insightful information regarding their assembly and disassembly in the cell. This phenomenon exemplifies how bacteria divide labor in the population by differentiating a sub-population into “tailocin-factories” that maximize the production of macro-molecules in a confined space using a highly ordered process.