8U02

CryoEM structure of D2 dopamine receptor in complex with GoA KE mutant and dopamine

Summary for 8U02

• Entry DOI: 10.2210/pdb8u02/pdb
• EMDB information: 41766 41776
• Descriptor: D(2) dopamine receptor, Guanine nucleotide-binding protein G(o) subunit alpha, Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1, ... (5 entities in total)
• Functional Keywords: gpcr, dopamine, drd2, dominant negative, membrane protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 4
• Total formula weight: 138218.20

Authors

Krumm, B.E.,Kapolka, N.J.,Fay, J.F.,Roth, B.L. (deposition date: 2023-08-28, release date: 2024-08-21, Last modification date: 2025-05-28)

Primary citation

Knight, K.M.,Krumm, B.E.,Kapolka, N.J.,Ludlam, W.G.,Cui, M.,Mani, S.,Prytkova, I.,Obarow, E.G.,Lefevre, T.J.,Wei, W.,Ma, N.,Huang, X.P.,Fay, J.F.,Vaidehi, N.,Smrcka, A.V.,Slesinger, P.A.,Logothetis, D.E.,Martemyanov, K.A.,Roth, B.L.,Dohlman, H.G.
A neurodevelopmental disorder mutation locks G proteins in the transitory pre-activated state.
Nat Commun, 15:6643-6643, 2024

PubMed Abstract: Many neurotransmitter receptors activate G proteins through exchange of GDP for GTP. The intermediate nucleotide-free state has eluded characterization, due largely to its inherent instability. Here we characterize a G protein variant associated with a rare neurological disorder in humans. Gα has a charge reversal that clashes with the phosphate groups of GDP and GTP. As anticipated, the purified protein binds poorly to guanine nucleotides yet retains wild-type affinity for G protein βγ subunits. In cells with physiological concentrations of nucleotide, Gα forms a stable complex with receptors and Gβγ, impeding effector activation. Further, we demonstrate that the mutant can be easily purified in complex with dopamine-bound D2 receptors, and use cryo-electron microscopy to determine the structure, including both domains of Gα, without nucleotide or stabilizing nanobodies. These findings reveal the molecular basis for the first committed step of G protein activation, establish a mechanistic basis for a neurological disorder, provide a simplified strategy to determine receptor-G protein structures, and a method to detect high affinity agonist binding in cells.

PubMed: 39103320
DOI: 10.1038/s41467-024-50964-z

Experimental method

ELECTRON MICROSCOPY (3.28 Å)