Molecular characterization of human double-stranded RNA specific adenosine deaminases (ADARs)

• Main Author: Ong, Zi Xin
• Other Authors: Luo Dahai
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Science
• Online Access: http://hdl.handle.net/10356/67909
• Institution: Nanyang Technological University

Adenosine deaminases acting on RNA (ADARs) are enzymes that performs adenosine-to-inosine (A-to-I) editing via adenosine deamination. The RNA editing capacity of the proteins makes ADARs major players in the regulation of important gene products, modulation of immune responses, outcome of viral infections, oncogenesis, and even developmental processes. Understanding the mechanism behind ADARs’ RNA substrate binding and catalysis would shed light on mechanisms of diseases related to ADAR dysfunction. In this study, soluble recombinant protein constructs of various ADAR1 and ADARB1 domains were generated. Sequence and structural requirements of RNA substrates were explored using various short dsRNA constructs. A spontaneous dissociation of ADAR1 dsRBD3 from the editase domain was observed, suggesting the solubility and activity of the ADAR1 editase domain alone. In addition, blunt-ended dsRNA as short as 10bp displayed good binding affinity to ADAR1 and ADARB1, suggesting the usefulness of short dsRNA substrates in protein-RNA co-crystallization. The results provide the basis to further study ADAR protein-RNA binding and catalysis.