The HeidelBAG unifies structural efforts of EMBL Heidelberg inclusive former PIs and the Heidelberg University Biochemistry Center (BZH). Central to all projects are large assemblies involved in chromosome organization and transcription control, in nuclear and cytoplasmic RNA regulation, in translational control by ribosome associated factors, in protein targeting and membrane protein insertion, or in post-translational and RNA modification and processing. Nearly all projects make use of integrated structural biology techniques (MX, SAXS/SANS, NMR, cryo-EM) combined with complementary biophysical approaches. MX remains the essential and invariant tool for high resolution information of challenging functional modules.