Introduction - This script shows the structure of a valinomycin. Valinomycin transports ions across a membrane by a shuttle mechanism. Scroll down until the text corresponding to the view is visible. (V.Z.Pletnev et al. Bioorg Khim 21 828 (1995))
This is the complex between valinomycin and potassium. The valinomycin completely surronds the ion with a hydrophobic surface which allows the ion to cross the membrane.
This cut away view shows the ion (YELLOW) inside the complex.