7XMR

CryoEM structure of the somatostatin receptor 2 (SSTR2) in complex with Gi1 and its endogeneous peptide ligand SST-14

Summary for 7XMR

• Entry DOI: 10.2210/pdb7xmr/pdb
• EMDB information: 33302
• Descriptor: Somatostatin receptor type 2, Guanine nucleotide-binding protein G(i) subunit alpha-1, Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1, ... (5 entities in total)
• Functional Keywords: g protein-coupled receptor, somatostatin receptor 2, cryo-em, signaling protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 5
• Total formula weight: 133991.11

Authors

Wenli, Z.,Shuo, H.,Na, Q.,Wenbo, Z.,Mengjie, L.,Dehua, Y.,Ming-Wei, W.,Wu, B.,Zhao, Q. (deposition date: 2022-04-26, release date: 2022-08-03, Last modification date: 2024-10-09)

Primary citation

Zhao, W.,Han, S.,Qiu, N.,Feng, W.,Lu, M.,Zhang, W.,Wang, M.,Zhou, Q.,Chen, S.,Xu, W.,Du, J.,Chu, X.,Yi, C.,Dai, A.,Hu, L.,Shen, M.Y.,Sun, Y.,Zhang, Q.,Ma, Y.,Zhong, W.,Yang, D.,Wang, M.W.,Wu, B.,Zhao, Q.
Structural insights into ligand recognition and selectivity of somatostatin receptors.
Cell Res., 32:761-772, 2022

PubMed Abstract: Somatostatin receptors (SSTRs) play versatile roles in inhibiting the secretion of multiple hormones such as growth hormone and thyroid-stimulating hormone, and thus are considered as targets for treating multiple tumors. Despite great progress made in therapeutic development against this diverse receptor family, drugs that target SSTRs still show limited efficacy with preferential binding affinity and conspicuous side-effects. Here, we report five structures of SSTR2 and SSTR4 in different states, including two crystal structures of SSTR2 in complex with a selective peptide antagonist and a non-peptide agonist, respectively, a cryo-electron microscopy (cryo-EM) structure of G-bound SSTR2 in the presence of the endogenous ligand SST-14, as well as two cryo-EM structures of G-bound SSTR4 in complex with SST-14 and a small-molecule agonist J-2156, respectively. By comparison of the SSTR structures in different states, molecular mechanisms of agonism and antagonism were illustrated. Together with computational and functional analyses, the key determinants responsible for ligand recognition and selectivity of different SSTR subtypes and multiform binding modes of peptide and non-peptide ligands were identified. Insights gained in this study will help uncover ligand selectivity of various SSTRs and accelerate the development of new molecules with better efficacy by targeting SSTRs.

PubMed: 35739238
DOI: 10.1038/s41422-022-00679-x

Experimental method

ELECTRON MICROSCOPY (3.1 Å)