STRUCTURAL AND MOLECULAR MECHANISMS OF DOUBLE-STRANDED RNA PROCESSING IN RNA INTERFERENCE PATHWAY

Abstract

RNase III family proteins are involved in the maturation of RNAi molecules and small functional RNAs. In the first project, we looked into the structure and function of an uncanonical Dicer DCR1, found in budding yeast P. Stipitis. Through RNA sequencing and mutations, we showed the specificity of PsDCR1 RNA cleavage in vitro. We also solved the structure of the RNase III domain and dsRBD1 of this protein. Meanwhile, there is a canonical pathway for miRNA biogenesis in mammals, but this is not universal to all miRNAs. In the second project, we utilized an RNA-centred strategy of pulling down proteins associated with primary miRNAs with which we isolated an RNA-binding protein, hnRNP Q. We demonstrated the protein-protein interactions and the influence hnRNP Q has towards key components and intermediates of the microRNA biogenesis pathway. We also managed to solve the novel structure of two RNA recognition motifs through X-ray crystallization.