20ZI

Cryo-EM structure of the human neurotensin receptor 1 (hNTSR1)-Gi1 complex in the GTP-bound, AHD-open NC state 1, plunge-frozen 0-5 seconds after GTP addition

Summary for 20ZI

• Entry DOI: 10.2210/pdb20zi/pdb
• EMDB information: 67431
• Descriptor: Guanine nucleotide-binding protein G(i) subunit alpha-1, Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1, Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2, ... (6 entities in total)
• Functional Keywords: gpcr, ntsr1, neurotensin, g-protein, membrane protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 6
• Total formula weight: 164777.19

Authors

Kobayashi, K.,Matsui, T.E.,Fukuda, M.,Kawakami, K.,Yamashita, K.,Kato, H.E. (deposition date: 2025-12-03, release date: 2026-06-03)

Primary citation

Kobayashi, K.,Kawakami, K.,Matsui, T.E.,Yokoi, S.,Fukuda, M.,Narita, T.J.,Arai, H.,Tambo, M.,Sumikama, T.,Tatsumi, M.,Yamashita, K.,Koyanagi, J.,Kugawa, M.,Ikeda, H.,Sumino, A.,Mitsutake, A.,Kobilka, B.K.,Inoue, A.,Kato, H.E.
The dynamic basis of G-protein recognition and activation by a GPCR.
Nature, 652:812-821, 2026

PubMed Abstract: G-protein-coupled receptor (GPCR) signalling occurs through heterotrimeric G proteins, whose selective activation leads to distinct cellular outcomes. Although more than 200 GPCR-G protein complex structures have been determined, these static snapshots provide limited insight into the dynamics of G-protein association and dissociation. Here we present cryo-electron microscopy structures of human neurotensin receptor type 1 (NTSR1) with minimally modified G and G, showing how the receptor's intracellular surface dynamically rearranges to accommodate each G-protein subtype. Furthermore, time-resolved cryo-electron microscopy analyses of NTSR1-G visualized G-protein dissociation processes on GDP/GTP binding. Characterization of more than 20 intermediates, complemented by mutational and computational analyses, identifies four key mechanistic features. First, GDP/GTP induces G release from both canonical and non-canonical active conformations with distinct kinetics. Second, NTSR1 uses common intracellular rearrangements to recognize different G-protein subtypes and to promote activation of a single subtype. Third, separation from Gβγ involves stepwise remodelling of the Gα switches I-III. Finally, G dissociates from the receptor through a pathway that is distinct from that of G, and the canonical and non-canonical NTSR1-G complexes further diverge in their dissociation trajectories. These findings provide a comprehensive framework for understanding GPCR signalling dynamics and guiding signal-targeted therapeutic development.

PubMed: 41813902
DOI: 10.1038/s41586-026-10228-w

Experimental method

ELECTRON MICROSCOPY (2.7 Å)