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-Structure paper
Title | Structures of the Rhodopsin-Transducin Complex: Insights into G-Protein Activation. |
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Journal, issue, pages | Mol Cell, Vol. 75, Issue 4, Page 781-790.e3, Year 2019 |
Publish date | Aug 22, 2019 |
Authors | Yang Gao / Hongli Hu / Sekar Ramachandran / Jon W Erickson / Richard A Cerione / Georgios Skiniotis / |
PubMed Abstract | Rhodopsin (Rho), a prototypical G-protein-coupled receptor (GPCR) in vertebrate vision, activates the G-protein transducin (G) by catalyzing GDP-GTP exchange on its α subunit (Gα). To elucidate the ...Rhodopsin (Rho), a prototypical G-protein-coupled receptor (GPCR) in vertebrate vision, activates the G-protein transducin (G) by catalyzing GDP-GTP exchange on its α subunit (Gα). To elucidate the determinants of G coupling and activation, we obtained cryo-EM structures of a fully functional, light-activated Rho-G complex in the presence and absence of a G-protein-stabilizing nanobody. The structures illustrate how G overcomes its low basal activity by engaging activated Rho in a conformation distinct from other GPCR-G-protein complexes. Moreover, the nanobody-free structures reveal native conformations of G-protein components and capture three distinct conformers showing the Gα helical domain (αHD) contacting the Gβγ subunits. These findings uncover the molecular underpinnings of G-protein activation by visual rhodopsin and shed new light on the role played by Gβγ during receptor-catalyzed nucleotide exchange. |
External links | Mol Cell / PubMed:31300275 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.3 - 3.9 Å |
Structure data | EMDB-20222, PDB-6oy9: EMDB-20223, PDB-6oya: |
Chemicals | ChemComp-RET: |
Source |
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Keywords | SIGNALING PROTEIN / GPCR / G protein / Complex / SIGNALING PROTEIN/IMMUNE SYSTEM / SIGNALING PROTEIN-IMMUNE SYSTEM complex |