Solution NMR vs Crystallography resolved by solid state NMR

On page 689-692 In the 4 Feb issue of Nature Cady et al. describe the solid state NMR structure of the influenza virus M2 proton channel in complex with amantadine (an inhibitor) in a lipid bilayer. From solution NMR studies four binding sites had previously been identified, although a high resolution crystal structure identified a single binding site in a different place (see references in the paper).

The solid state NMR structure identifies a single high-affinity binding site and four low-affinity binding sites at locations as shown in the previous studies. This shows both solution NMR and Crystallography were "right", although the second one perhaps a bit more so, because it appears the single high-affinity binding site is more biologically relevant.