Predicted structure of Honokiol binding to Hla. (a) View of the heptamer down the sevenfold axis (PDB ID 7AHL). Each promoter is shown with a different colour and the predicted residues contacting Honokiol are shown as coloured sticks. (b) Ribbon representation of the heptamer viewed parallel to the sevenfold axis. (c) The ribbon representation of a protomeric subunit structure is extracted from the heptamer with the triangle region and stem labelled. (d) Ribbon representation of monomeric Hla-bound Honokiol with the allosteric region and residue information labelled. The allosteric region is coloured in pink. The residues LYS58, GLY59, and THR60 are coloured red. The residues SER218, LEU219, SER222, GLY223, PHE224, SER225, PRO226, and ASP227 are coloured purple. The residues LYS147, TYR148, VAL149 are coloured yellow. Honokiol is coloured orange. The interacting residues LYS147, TYR148, and VAL149 are located in the structure of the channel. Consequently, Honokiol influences the formation of the membrane channel or the channel structure, which leads to the loss of the heptamer function.