The rod-shaped bacterium Yersinia enterocolitica, which is transmitted through contaminated food, causes gastrointestinal diseases. In Germany alone, several thousand cases are reported annually. Yersinia uses a rather sophisticated tool—its injection apparatus—to infect humans. Not only does the apparatus look like a syringe, it actually serves a similar purpose. A molecular “needle”, which sticks out from the bacterium’s surface, extends across the bacterial membranes to the host cell. It is through this needle that the bacterium “injects” substances that facilitate infection of the host. Now, for the first time, an interdisciplinary team of HZI scientists together with their colleagues at the Biozentrum of the University of Basel and at the Ecole Polytechnique Fédérale de Lausanne in Switzerland, has presented the structure ofYersinia enterocolitica‘s injectisome in high-resolution and 3D. They published their results in the digital scientific magazine eLife.