Gene silencing via micro-RNAs is a cell’s main mechanism in maintaining cellular homeostasis. This is directly evidenced by the immense number of disease states directly correlated to the improper function or maturation of a micro-RNA. Initiation of the canonical micro-RNA maturation pathway begins via substrate selection and processing of a primary micro-RNA by the catalytic complex, Microprocessor, in the nucleus. The catalytic unit of this complex, Drosha, has no means to recognize substrate as its double stranded RNA binding domain has been empirically shown to not bind double-stranded RNA. Further analysis of this domain via human cell-based processing assays revealed that, while this domain is not utilized via its canonical nature, is imperative to Microprocessor function- deletion of the domain leads to complete ablation of primary-micro-RNA processing. In this thesis, I describe my work toward understanding the role of this domain utilizing classic biochemical and biophysical techniques.
