Serotonin 4 (5-HT4) receptor-Gi-scFv16 complexSerotonin 4 (5-HT4) receptor-Gi-scFv16 complex

Structural highlights

7xta is a 5 chain structure with sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Electron Microscopy, Resolution 3.2Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

GNAI1_HUMAN Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(i) proteins are involved in hormonal regulation of adenylate cyclase: they inhibit the cyclase in response to beta-adrenergic stimuli. The inactive GDP-bound form prevents the association of RGS14 with centrosomes and is required for the translocation of RGS14 from the cytoplasm to the plasma membrane. May play a role in cell division.[1] [2]

Publication Abstract from PubMed

Serotonin (or 5-hydroxytryptamine, 5-HT) is an important neurotransmitter that activates 12 different G protein-coupled receptors (GPCRs) through selective coupling of G(s), G(i,) or G(q) proteins. The structural basis for G protein subtype selectivity by these GPCRs remains elusive. Here, we report the structures of the serotonin receptors 5-HT(4), 5-HT(6), and 5-HT(7) with G(s), and 5-HT(4) with G(i1). The structures reveal that transmembrane helices TM5 and TM6 alternate lengths as a macro-switch to determine receptor's selectivity for G(s) and G(i), respectively. We find that the macro-switch by the TM5-TM6 length is shared by class A GPCR-G protein structures. Furthermore, we discover specific residues within TM5 and TM6 that function as micro-switches to form specific interactions with G(s) or G(i). Together, these results present a common mechanism of G(s) versus G(i) protein coupling selectivity or promiscuity by class A GPCRs and extend the basis of ligand recognition at serotonin receptors.

GPCRs steer G(i) and G(s) selectivity via TM5-TM6 switches as revealed by structures of serotonin receptors.,Huang S, Xu P, Shen DD, Simon IA, Mao C, Tan Y, Zhang H, Harpsoe K, Li H, Zhang Y, You C, Yu X, Jiang Y, Zhang Y, Gloriam DE, Xu HE Mol Cell. 2022 Jul 21;82(14):2681-2695.e6. doi: 10.1016/j.molcel.2022.05.031. , Epub 2022 Jun 16. PMID:35714614[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Cho H, Kehrl JH. Localization of Gi alpha proteins in the centrosomes and at the midbody: implication for their role in cell division. J Cell Biol. 2007 Jul 16;178(2):245-55. PMID:17635935 doi:10.1083/jcb.200604114
  2. Johnston CA, Siderovski DP. Structural basis for nucleotide exchange on G alpha i subunits and receptor coupling specificity. Proc Natl Acad Sci U S A. 2007 Feb 6;104(6):2001-6. Epub 2007 Jan 30. PMID:17264214
  3. Huang S, Xu P, Shen DD, Simon IA, Mao C, Tan Y, Zhang H, Harpsoe K, Li H, Zhang Y, You C, Yu X, Jiang Y, Zhang Y, Gloriam DE, Xu HE. GPCRs steer Gi and Gs selectivity via TM5-TM6 switches as revealed by structures of serotonin receptors. Mol Cell. 2022 Jul 21;82(14):2681-2695.e6. doi: 10.1016/j.molcel.2022.05.031., Epub 2022 Jun 16. PMID:35714614 doi:http://dx.doi.org/10.1016/j.molcel.2022.05.031

7xta, resolution 3.20Å

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