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Open data
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Basic information
| Entry | Database: PDB / ID: 9oxa | |||||||||||||||||||||
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| Title | CryoEM structure of Gi-coupled TAS2R43 with aristolochic acid I | |||||||||||||||||||||
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Keywords | SIGNALING PROTEIN / GPCR | |||||||||||||||||||||
| Function / homology | Function and homology informationbitter taste receptor activity / taste receptor activity / detection of chemical stimulus involved in sensory perception of bitter taste / motile cilium / Class C/3 (Metabotropic glutamate/pheromone receptors) / ciliary membrane / adenylate cyclase inhibitor activity / positive regulation of protein localization to cell cortex / T cell migration / positive regulation of relaxation of smooth muscle ...bitter taste receptor activity / taste receptor activity / detection of chemical stimulus involved in sensory perception of bitter taste / motile cilium / Class C/3 (Metabotropic glutamate/pheromone receptors) / ciliary membrane / adenylate cyclase inhibitor activity / positive regulation of protein localization to cell cortex / T cell migration / positive regulation of relaxation of smooth muscle / Adenylate cyclase inhibitory pathway / D2 dopamine receptor binding / adenylate cyclase-inhibiting serotonin receptor signaling pathway / G protein-coupled serotonin receptor binding / cellular response to forskolin / regulation of mitotic spindle organization / chemokine-mediated signaling pathway / Regulation of insulin secretion / neuropeptide signaling pathway / response to prostaglandin E / positive regulation of cholesterol biosynthetic process / electron transport chain / negative regulation of insulin secretion / G protein-coupled receptor binding / response to peptide hormone / G protein-coupled receptor activity / G-protein beta/gamma-subunit complex binding / centriolar satellite / adenylate cyclase-modulating G protein-coupled receptor signaling pathway / adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway / Olfactory Signaling Pathway / Activation of the phototransduction cascade / G protein-coupled acetylcholine receptor signaling pathway / G beta:gamma signalling through PLC beta / Presynaptic function of Kainate receptors / Thromboxane signalling through TP receptor / Activation of G protein gated Potassium channels / Inhibition of voltage gated Ca2+ channels via Gbeta/gamma subunits / G-protein activation / Glucagon signaling in metabolic regulation / G beta:gamma signalling through CDC42 / Prostacyclin signalling through prostacyclin receptor / Synthesis, secretion, and inactivation of Glucagon-like Peptide-1 (GLP-1) / G beta:gamma signalling through BTK / photoreceptor disc membrane / ADP signalling through P2Y purinoceptor 12 / Sensory perception of sweet, bitter, and umami (glutamate) taste / Glucagon-type ligand receptors / GDP binding / Adrenaline,noradrenaline inhibits insulin secretion / Vasopressin regulates renal water homeostasis via Aquaporins / Glucagon-like Peptide-1 (GLP1) regulates insulin secretion / G alpha (z) signalling events / cellular response to catecholamine stimulus / ADP signalling through P2Y purinoceptor 1 / ADORA2B mediated anti-inflammatory cytokines production / G beta:gamma signalling through PI3Kgamma / adenylate cyclase-activating dopamine receptor signaling pathway / Cooperation of PDCL (PhLP1) and TRiC/CCT in G-protein beta folding / GPER1 signaling / cellular response to prostaglandin E stimulus / heterotrimeric G-protein complex / G alpha (12/13) signalling events / Inactivation, recovery and regulation of the phototransduction cascade / G-protein beta-subunit binding / extracellular vesicle / sensory perception of taste / sperm principal piece / Thrombin signalling through proteinase activated receptors (PARs) / signaling receptor complex adaptor activity / adenylate cyclase-activating G protein-coupled receptor signaling pathway / retina development in camera-type eye / GTPase binding / G protein activity / fibroblast proliferation / Ca2+ pathway / midbody / cell cortex / High laminar flow shear stress activates signaling by PIEZO1 and PECAM1:CDH5:KDR in endothelial cells / G alpha (i) signalling events / G alpha (s) signalling events / phospholipase C-activating G protein-coupled receptor signaling pathway / G alpha (q) signalling events / Hydrolases; Acting on acid anhydrides; Acting on GTP to facilitate cellular and subcellular movement / Ras protein signal transduction / periplasmic space / electron transfer activity / Extra-nuclear estrogen signaling / cell population proliferation / ciliary basal body / iron ion binding / G protein-coupled receptor signaling pathway / cell division / lysosomal membrane / GTPase activity / heme binding / centrosome / synapse / GTP binding / protein-containing complex binding Similarity search - Function | |||||||||||||||||||||
| Biological species | Homo sapiens (human)![]() | |||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.9 Å | |||||||||||||||||||||
Authors | Kim, Y. / Gumpper, R.H. / Roth, B.L. | |||||||||||||||||||||
| Funding support | United States, 1items
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Citation | Journal: Nat Struct Mol Biol / Year: 2026Title: Structural insights into coffee bitter taste perception by TAS2R43 receptor. Authors: Yoojoong Kim / Ryan H Gumpper / Yuxuan Zhuang / Ron O Dror / Bryan L Roth / ![]() Abstract: Bitter taste functions as a means of both protection against potentially toxic compounds and savoring bitter tasting foods and beverages. Among the 26 bitter taste receptors, taste receptor type 2 ...Bitter taste functions as a means of both protection against potentially toxic compounds and savoring bitter tasting foods and beverages. Among the 26 bitter taste receptors, taste receptor type 2 member 43 (TAS2R43) has been identified as key for recognizing the bitter taste of coffee. TAS2R43 has also been implicated in many other physiological processes, including the regulation of glucagon-like peptide 1 release from the intestine, bronchodilation, innate immunity and metabolism. Here we report cryo-electron microscopy structures of human TAS2R43 coupled with inhibitory G protein or gustducin (G) stabilized by the potent nephrotoxin and carcinogen aristolochic acid I. Both structures revealed that aristolochic acid I binds in a presumed orthosteric pocket shared with other bitter taste receptor. Further structural, functional and computational studies revealed potential modes for coffee's constituents including caffeine and cafestol, which are bitter tastants from coffee. Lastly, long-timescale molecular dynamics simulations identified potential cryptic allosteric pockets in TAS2R43. These structures could accelerate the search for specific bitter taste ligands that ultimately may be therapeutically useful. | |||||||||||||||||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 9oxa.cif.gz | 245.1 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9oxa.ent.gz | 181.5 KB | Display | PDB format |
| PDBx/mmJSON format | 9oxa.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/ox/9oxa ftp://data.pdbj.org/pub/pdb/validation_reports/ox/9oxa | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 70964MC ![]() 9oxbC M: map data used to model this data C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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| 1 |
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Components
-Guanine nucleotide-binding protein ... , 3 types, 3 molecules BCA
| #2: Protein | Mass: 42936.668 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: GNB1 / Production host: ![]() |
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| #3: Protein | Mass: 7861.143 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: GNG2 / Production host: ![]() |
| #4: Protein | Mass: 40414.047 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: GNAI1 / Production host: ![]() |
-Protein / Antibody , 2 types, 2 molecules RD
| #1: Protein | Mass: 72130.312 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: cybC, TAS2R43 / Production host: ![]() |
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| #5: Antibody | Mass: 28668.922 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
-Non-polymers , 2 types, 8 molecules 


| #6: Chemical | ChemComp-GOQ / |
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| #7: Water | ChemComp-HOH / |
-Details
| Has ligand of interest | Y |
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| Has protein modification | Y |
-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
| Component | Name: GPCR complex 1 / Type: COMPLEX / Entity ID: #1-#5 / Source: MULTIPLE SOURCES |
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| Source (natural) | Organism: Homo sapiens (human) |
| Source (recombinant) | Organism: ![]() |
| Buffer solution | pH: 7.5 |
| Specimen | Conc.: 7 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
| Specimen support | Grid material: GOLD / Grid mesh size: 300 divisions/in. / Grid type: Quantifoil R1.2/1.3 |
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE-PROPANE / Humidity: 95 % / Chamber temperature: 277.15 K |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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| Microscopy | Model: FEI TALOS ARCTICA |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 200 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 20000 nm / Nominal defocus min: 5000 nm |
| Image recording | Electron dose: 60 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
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| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
| 3D reconstruction | Resolution: 2.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 583017 / Symmetry type: POINT | ||||||||||||||||||||||||
| Refinement | Highest resolution: 2.9 Å Stereochemistry target values: REAL-SPACE (WEIGHTED MAP SUM AT ATOM CENTERS) | ||||||||||||||||||||||||
| Refine LS restraints |
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About Yorodumi




Homo sapiens (human)

United States, 1items
Citation








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FIELD EMISSION GUN