This proposal clusters crystallography projects at the EMBL Grenoble, IBS and IAB working on different topics with a focus on nucleic acid-protein complexes and host-pathogen interactions. The proposers have long-standing experience in the use, as well as the development of beam lines for macromolecular crystallography and have participated in successive BAG applications over the years, mostly at the ESRF but also at other synchrotrons (i.e. Soleil, Petra II, Diamond, SLS)