Figure 5.

CEB25 variant instability correlates to thermal stability of its associated G4

A, B Thermal stability dependence on loop length and position as measured by UV and CD spectroscopy. All melting temperatures (T_m) were obtained in 1 mM KPi buffer at ˜ 4 μM DNA strand concentrations. (A) Thermal stability of CEB25 G4 variants is inversely correlated to the central loop length (P-values obtained using the Spearman correlation test). Other loops are single thymine. The two T_m^UV values for a central loop of 3 nt correspond toL131(TGT) andL131(TTT), respectively. (B) Effect of the position of a single 2- or 3-nt-long loop and permutation of two or three 2-nt-long loops on the thermal stability of CEB25 G4 variants. All loop residues are thymine.

C In vivo instability of CEB25 allele variants plotted as a function of the melting temperature of the corresponding G4 measured by UV spectroscopy, in WT cells treated with Phen-DC₃ (left panel) and inpif1Δ cells (right panel).P-values and correlation coefficients were obtained using a two-tailed Spearman correlation test.

D Sequence effect of single loop residue substitutions on the thermal stability of theCEB25-L111 G4. Melting temperatures (T_m) were obtained in 1 mM KPi buffer at ˜ 4 μM DNA strand concentrations.

E Sequence effect of three 1-nt-long loops on the CEB25 instability in WT cells treated with Phen-DC₃ (left panel, strains ANT1903, ANT1953, and ANT1936) and inpif1Δ cells (right panel, strains ANT1917, ANT1974, and ANT1980). Analysis was done as in Fig1B.