Download MendeleyFormation of left-handed helices by C2'-fluorinated nucleic acids under physiological salt conditions.
El-Khoury, R., Cabrero, C., Movilla, S., Kaur, H., Friedland, D., Dominguez, A., Thorpe, J.D., Roman, M., Orozco, M., Gonzalez, C., Damha, M.J.(2024) Nucleic Acids Res 52: 7414-7428
- PubMed: 38874502
- DOI: https://doi.org/10.1093/nar/gkae508
- Primary Citation of Related Structures:
8QDU, 8QE4, 8QOR - PubMed Abstract:
Recent findings in cell biology have rekindled interest in Z-DNA, the left-handed helical form of DNA. We report here that two minimally modified nucleosides, 2'F-araC and 2'F-riboG, induce the formation of the Z-form under low ionic strength. We show that oligomers entirely made of these two nucleosides exclusively produce left-handed duplexes that bind to the Zα domain of ADAR1. The effect of the two nucleotides is so dramatic that Z-form duplexes are the only species observed in 10 mM sodium phosphate buffer and neutral pH, and no B-form is observed at any temperature. Hence, in contrast to other studies reporting formation of Z/B-form equilibria by a preference for purine glycosidic angles in syn, our NMR and computational work revealed that sequential 2'F…H2N and intramolecular 3'H…N3' interactions stabilize the left-handed helix. The equilibrium between B- and Z- forms is slow in the 19F NMR time scale (≥ms), and each conformation exhibited unprecedented chemical shift differences in the 19F signals. This observation led to a reliable estimation of the relative population of B and Z species and enabled us to monitor B-Z transitions under different conditions. The unique features of 2'F-modified DNA should thus be a valuable addition to existing techniques for specific detection of new Z-binding proteins and ligands.
Organizational Affiliation:
Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8, Canada.
