Na+ may promote PIP2 binding to GIRK channels by breaking a hydrogen bond formed between an aspartate in the βC-βD sheet and an arginine66,91. These high-resolution protein structures have provided important snapshots of inward rectifiers in different conformational states as well as provided detailed maps for the location of functional domains. The next wave of high-resolution structural analysis should provide a more precise 3-D model of the conformational changes that underlie the gating mechanisms of inwardly rectifying channels.
