We study the spatial organization, functional dynamics, and evolutionary driving forces of biomolecular interactions in metabolic pathways and macromolecular complexes. We integrate structural data with biochemical, biophysical and computational approaches to decipher the architectural principles and the dynamics, the functioning, and possible catalytic advantages of these assemblies. One example of this research is the characterization of the AROM complex, an assembly of ten enzymatic domains catalyzing the five central steps of the shikimate pathway in fungi. Another example is the ubiquitin-proteasome system (UPS), a key system for therapeutic intervention.