Download MendeleyADAR activation by inducing a syn conformation at guanosine adjacent to an editing site.
Doherty, E.E., Karki, A., Wilcox, X.E., Mendoza, H.G., Manjunath, A., Matos, V.J., Fisher, A.J., Beal, P.A.(2022) Nucleic Acids Res 50: 10857-10868
- PubMed: 36243986
- DOI: https://doi.org/10.1093/nar/gkac897
- Primary Citation of Related Structures:
8E0F, 8E4X - PubMed Abstract:
ADARs (adenosine deaminases acting on RNA) can be directed to sites in the transcriptome by complementary guide strands allowing for the correction of disease-causing mutations at the RNA level. However, ADARs show bias against editing adenosines with a guanosine 5' nearest neighbor (5'-GA sites), limiting the scope of this approach. Earlier studies suggested this effect arises from a clash in the RNA minor groove involving the 2-amino group of the guanosine adjacent to an editing site. Here we show that nucleosides capable of pairing with guanosine in a syn conformation enhance editing for 5'-GA sites. We describe the crystal structure of a fragment of human ADAR2 bound to RNA bearing a G:G pair adjacent to an editing site. The two guanosines form a Gsyn:Ganti pair solving the steric problem by flipping the 2-amino group of the guanosine adjacent to the editing site into the major groove. Also, duplexes with 2'-deoxyadenosine and 3-deaza-2'-deoxyadenosine displayed increased editing efficiency, suggesting the formation of a Gsyn:AH+anti pair. This was supported by X-ray crystallography of an ADAR complex with RNA bearing a G:3-deaza dA pair. This study shows how non-Watson-Crick pairing in duplex RNA can facilitate ADAR editing enabling the design of next generation guide strands for therapeutic RNA editing.
Organizational Affiliation:
Department of Chemistry, University of California, Davis, CA, USA.
