Crystal structure of rhodopsin in complex with a mini-Gosheds light on the principles of G protein selectivity.Tsai, C.J., Pamula, F., Nehme, R., Muhle, J., Weinert, T., Flock, T., Nogly, P., Edwards, P.C., Carpenter, B., Gruhl, T., Ma, P., Deupi, X., Standfuss, J., Tate, C.G., Schertler, G.F.X.
(2018) Sci Adv 4: eaat7052-eaat7052
- PubMed: 30255144
- DOI: 10.1126/sciadv.aat7052
- PubMed Abstract:
Selective coupling of G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors (GPCRs) to specific Gα-protein subtypes is critical to transform extracellular signals, carried by natural ligands and clinical drugs, into cellular ...
Selective coupling of G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors (GPCRs) to specific Gα-protein subtypes is critical to transform extracellular signals, carried by natural ligands and clinical drugs, into cellular responses. At the center of this transduction event lies the formation of a signaling complex between the receptor and G protein. We report the crystal structure of light-sensitive GPCR rhodopsin bound to an engineered mini-G o protein. The conformation of the receptor is identical to all previous structures of active rhodopsin, including the complex with arrestin. Thus, rhodopsin seems to adopt predominantly one thermodynamically stable active conformation, effectively acting like a "structural switch," allowing for maximum efficiency in the visual system. Furthermore, our analysis of the well-defined GPCR-G protein interface suggests that the precise position of the carboxyl-terminal "hook-like" element of the G protein (its four last residues) relative to the TM7/helix 8 (H8) joint of the receptor is a significant determinant in selective G protein activation.
Department of Biology, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland.,Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK.,Fitzwilliam College, University of Cambridge, Cambridge, UK.,Condensed Matter Theory Group, PSI, 5232 Villigen PSI, Switzerland.,Laboratory of Biomolecular Research, Paul Scherrer Institute (PSI), 5232 Villigen PSI, Switzerland.