Plant cell wall polysaccharides, notably cellulose, comprise the most abundant source of carbon and energy in the biosphere and is recognized as one of the only sustainable and renewable primary energy resources. An emerging number of anaerobic bacteria use a large, extracellular enzyme complex, termed the cellulosome, to break down these materials in a highly efficient and synergistic manner. The topology of the scaffoldin subunit of the cellulosome and the assembly and organization of the the various hydrolytic enzymes on the scaffoldin subunit that represents the key structural features of this multi-enzyme complex that contribution to its overall function. We are employing a dissect-and-build structure-based approach, involving X-ray crystallography and small-angle X-ray scattering, to understand molecular determinants of cellulosome assembly, organization, and function. Our findings will provide valuable structural insights in the generation of designer cellulose-degrading systems for potential industrial uses.