G Protein-Coupled Receptors Contain Two Conserved Packing Clusters.

G protein-coupled receptors (GPCRs) have evolved a seven-transmembrane helix framework that is responsive to a wide range of extracellular signals. An analysis of the interior packing of family A GPCR crystal structures reveals two clusters of highly packed residues that facilitate tight transmembrane helix association. These clusters are centered on amino acid positions 2.

Sequential structural changes in rhodopsin occurring upon photoactivation.

We describe the use of solid-state magic angle spinning NMR spectroscopy for characterizing the structure and dynamics of dark, inactive rhodopsin and the active metarhodopsin II intermediate. Solid-state NMR spectroscopy is well suited for structural measurements in both detergent micelles and membrane bilayer environments. We first outline the methods for large-scale production of stable, functional rhodopsin containing (13)C- and (15)N-labeled amino acids.