Fig. 2
From: G4Boost: a machine learning-based tool for quadruplex identification and stability prediction
Representation of G4 structure folding. Crystal structure of a G-quadruplex (PDB ID: 3IBK [63]) from the top and the side (A) and its RNAfold representation (B) are shown. the 3D model of 3IBK is colored by its bases (guanines in green, adenines in gray, and thymines in red) and the backbone is colored blue. Two K+ ions are shown at the center. Hydrogen bonds between the K+ ion and the guanines are shown as yellow dotted lines. Bonding between the nucleotides is shown as dash lines in the RNAfold representation which is followed by the G4 sequence and the dot plus notation of the structure (B)