New paper in Science: A new contractile injection system in an amoeba symbiont

Protein secretion systems are key mechanisms of intracellular bacteria to infect eukaryotic host cells. Matthias Horn and his team at DoME together with Martin Pilhofer’s lab at the ETH Zürich now discovered and characterized a novel secretion system in the amoeba symbiont Amoebophilus asiaticus. Using advanced cryo-electron tomography methods they resolved the three-dimensional structure of the secretion system in its natural cellular context. The system showed striking similarities to contractile phages and other contractile injection systems, but evolved independently from known bacterial secretion systems.