Figure 1.

(A) The promoter sequence of the BCL-2 gene and its modifications. The top sequence is the 39-mer wild-type G-rich sequence (Pu39). The six G-runs with three or more guanines are underlined and numbered. Pu30 is the wild-type 30-mer G-rich sequence containing the I–V G-runs; the numbering used in this study is shown for Pu30. The guanine residues that are involved in the tetrad formation of the major BCL-2 G-quadruplex 1245G4 are shown in red. The mutations are shown in cyan. (B) DMS footprinting of the wild-type Pu39 with densitometric scans (left) and Pu30 (right). (C) Imino regions of 1D ¹H NMR spectra of BCL-2 promoter sequences at 25 °C in 45 mM K⁺, pH 7.0. (D) CD spectra of Pu30 sequences in 95 mM K⁺.