Proteins are essential macromolecules for all living organisms. They provide cellular

structure and perform most of the metabolic functions essential for all life. The importance of

proteins makes them the most studied and exploited macromolecules. We can exploit the

structure of a protein to design a specific therapeutic to treat a disease or we can use proteins as biocatalysts for the efficient creation of molecules. In many instances, these applications of proteins are difficult to achieve. The work in this dissertation focuses on the development and evaluations of novel techniques to aid in the study and use of proteins.

The first part of this dissertation focus on the creation of a series of symmetric oligomers

to be used as crystallization scaffolds. Such scaffolds are intended to induce their symmetry onto asymmetric protein crystallization target proteins. The ability to determine the crystal structure can be essential for the creation of new targeted drugs or the better understanding of a biological process. Unfortunately many proteins fail to crystallize for reasons that are not well understood. It is thought that such induction of symmetry and variety of geometrically distinct scaffolds will aid in the crystallization of difficult-to-crystallize proteins. Preliminary results of these novel scaffolds and existing scaffolds are described.

In the second part, applications of symmetric scaffolds for the creation of enzymatic materials are presented. These purely proteinaceous assemblies are designed to replicate previous

described enzyme encapsulating materials. These materials typically improve enzyme reaction rates and product extraction. The final part of the dissertation focuses on the shell protein PduA from the 1,2-propanediol-utilization bacterial microcompartment (MCPs). These MCPs encapsulate metabolic pathways and contain volatile or toxic pathway intermediates. Research into turning these MCPs into bioreactors containing non-native enzymes is ongoing in many labs. Full realization of this technology relies on the encapsulation of new metabolic enzymes and transport of novel substrate and products through the shells. These processes are poorly understood, here structural studies of shell protein permutations. These permutations alter the topology of the shell protein allowing the scaffolding of proteins to the exterior surface of the MCPs. Finally, the efforts to elicited the interaction of specific targeting sequences to shell protein by x-ray crystallography are discussed.