Figure 5. RNA and protein recognition of the same riboflavin ligand.
Molecular interactions of riboflavin (blue) with riboflavin kinase protein (Protein Data Bank (PDB) identifier: inb9)69 (left) and flavin mononucleotide (FMN) riboswitch RNA (PDB ID: 3f4g)70 (right). Hydrogen bonds are shown with green dashed lines, and van der Waals and stacking interactions are emphasized with red arcs. Water molecules and metal ions are shown as cyan and green spheres, respectively. Riboflavin has a molecular mass of 376 Da, an octanol–water partition coefficient of −0.76, a total polar surface area of 162 and a quantitative estimate of drug-likeness score of 0.33. Bottom images were initially drafted with LigPlot+.