Fig. 4: NMR solution structures of KRAS-G4 and its complexes with berberine and coptisine.

Superposition of the ten lowest energy NMR structures of the free KRAS-G4 (a), berberine-KRAS-G4 (b), and coptisine-KRAS-G4 (c) by NOE-restrained structure calculations. Yellow, berberine; green, coptisine; cyan, flanking guanine; gray, tetrad guanine; magenta, adenine; blue, thymine; orange, cytosine.