The protein capsid of an icosahedral virus can be considered a natural scaffold system for the RNA genome which it packages. It is possible to manipulate the nature of this packaging to gain structural information regarding the encapsidated molecule. Satellite Tobacco Necrosis Virus (STNV), is a small T=1 plant satellite virus. It is possible to express and purify intact virus like particles recombinantly. The refined structure of these particles has been solved crystallographically to a resolution of 1.4 A, however no RNA density was visible within this structure. This structure has been re-solved within this thesis to low resolution, 6 A, revealing distinct density in addition to that of protein, attributable to RNA. The recombinant capsid is packaging non-self RNA and doing so with a degree of icosahedral order. The recognition sequence allowing STNV to package its own RNA genome specifically has not been identified. In an effort to achieve this, the process of SELEX has been implemented. Several sequences matching those of the STNV-1 genome have been identified indicating that this procedure has succeeded in selecting RNA sequences which mimic those expected to bind in nature. These matching sequences span the length of the genome, indicating that packaging may not be a result of binding to a single site on the RNA. As the STNV capsid is already designed to function as a scaffold for genomic RNA, it provides an obvious start point for the design of a more complex scaffold. The development of the STNV capsid to be of use as a macromolecular scaffold system is addressed within this thesis. Three hurdles associated with such a system have been identified and addressed by designing mutant STNV coat protein monomers. Upon expression and purifiCation differences in the biochemical properties between the wild type protein and the mutants have been identified.