1. Distinct differences in metal ion specificity of RNA and DNA G-quadruplexes.
- Author
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Guiset Miserachs H, Donghi D, Börner R, Johannsen S, and Sigel RK
- Subjects
- Base Sequence, Cations, Divalent chemistry, Cations, Divalent metabolism, Cations, Monovalent chemistry, Cations, Monovalent metabolism, Circular Dichroism, DNA genetics, DNA metabolism, Hydrogen-Ion Concentration, Metals metabolism, Nucleic Acid Denaturation, Oligonucleotides chemistry, Oligonucleotides genetics, Oligonucleotides metabolism, RNA genetics, RNA metabolism, Spectrophotometry, Temperature, Thermodynamics, Water chemistry, DNA chemistry, G-Quadruplexes, Metals chemistry, RNA chemistry
- Abstract
RNA G-quadruplexes, as their well-studied DNA analogs, require the presence of cations to fold and remain stable. This is the first comprehensive study on the interaction of RNA quadruplexes with metal ions. We investigated the formation and stability of two highly conserved and biologically relevant RNA quadruplex-forming sequences (24nt-TERRA and 18nt-NRAS) in the presence of several monovalent and divalent metal ions, namely Li
+ , Na+ , K+ , Rb+ , Cs+ , NH4 + , Mg2+ , Ca2+ , Sr2+ , and Ba2+ , K+ , K+ , Rb+ , NH4 + in water, shifts the equilibrium to the folded quadruplex form, whereby the NRAS sequence responds stronger than TERRA. However, only K2+ and Ba2+ in water, shifts the equilibrium to the folded quadruplex form, whereby the NRAS sequence responds stronger than TERRA. However, only K+ and Sr2+ lead to a significant increase in the stability of the folded structures, which is consistent with their coordination to the O6 atoms from the G-quartet guanosines. Compared to the respective DNA motives, dNRAS and htelo, the RNA sequences are not stabilized by Na+ ions. Finally, the difference in response between NRAS and TERRA, as well as to the corresponding DNA sequences with respect to different metal ions, could potentially be exploited for selective targeting purposes.- Published
- 2016
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