Figure 2.

The [Mg²⁺]-dependence of the ion-binding fractions per nucleotide for six RNA/DNA-solution systems: (A) 40 bp A-RNA duplex with 10 mM Na⁺, (B) 40 bp B-DNA duplex with 5 mM Na⁺, (C) adenine riboswitch (PDB: 4TZX (97)) with 50 mM K⁺, (D) rRNA-protein complex (PDB: 1HC8 (98)) with 60 mM K⁺, tRNA (PDB: 1TRA (99)) with (E) 10 mM Na⁺ and (F) 32 mM Na⁺. The experimental data are from (100, 101, 102, 103, 104), respectively.