Emerging structural explanations of ionotropic glutamate receptor function

High-resolution studies of ionotropic glutamate receptor (iGluR) extracellular domains are beginning to bridge the gap between structure and function. Crystal structures have defined the ligand binding pocket well beyond what was suggested by mutational analysis and homology models alone, providing initial suggestions about the mechanisms of channel gating and desensitization. NMR-derived backbone dynamics and molecular dynamics simulations have added further insights into the role of protein dynamics in receptor function. As a whole, the current knowledge of iGluR structure in conjunction with new advances in the understanding of K+ channels provides a vastly improved understanding of iGluR function. This review focuses on structural and dynamic studies of the extracellular ligand binding domain of iGluRs and the pore region of K+ channels that have contributed to mechanistic insights into the processes of iGluR gating and desensitization.