This proposal gathers Principal investigators from French Institutions that use cryo-EM to unravel the molecular mechanisms associated with various biological processes. Scientists belong to 8 centres that currently use Cryo-EM and have already used ESRF CM01 beamline. All the PIs in this application have submitted application in the two previous Rolling access applications and have or will soon collect data. Most of them will thus need Beam-time prior to august 2020. According to our listing, 14 projects are ready for data collection at ESRF CM01. Projects include the study of bacterial secretion systems (Bordeaux, Lyon, Paris), viruses and their infection mechanisms (Marseille), translation and its control (Bordeaux, Toulouse, Paris, Strasbourg), transcription (Strasbourg, Paris) and Macromolecular transport (Bordeaux, Lyon, Strasbourg).