Supplementary Figure 2: The G-rich sequence found within the 3′ UTR of L1Hs folds into a G-quadruplex motif in vitro at both the DNA and the RNA level.
From: G-quadruplex structures within the 3′ UTR of LINE-1 elements stimulate retrotransposition
UV-melting profile followed at 295 nm of the L1Hs-DNA-G4 (a) and L1Hs-RNA-G4 (b) in the presence of 10 mM LiCl (orange line), NaCl (red line) or KCl (blue line). A cation-dependent hypochromic transition is characteristic of G4 formation. Circular dichroism (CD) spectra of the L1Hs-DNA-G4 (c) and L1Hs-RNA-G4 (d) in the presence of 100 mM LiCl (orange line), NaCl (red line) or KCl (blue line). All CD spectra are characterized by a minimum at 240 nm and a maximum at 263 nm characteristic of G4 formation. Expansion of the 1H NMR spectra of L1Hs-DNA-G4 (e) and L1Hs-RNA-G4 (f) pre-annealed in a 100 mM KCl containing buffer. Both NMR spectra exhibit characteristic imino proton signals shifted downfield (between 10 to 12 ppm) characteristic of Hoogsteen hydrogen bonding and G4 formation.
