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Yorodumi- PDB-8vv3: Structure of the insect gustatory receptor Gr9 from Bombyx mori i... -
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-Basic information
Entry | Database: PDB / ID: 8vv3 | ||||||
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Title | Structure of the insect gustatory receptor Gr9 from Bombyx mori in complex with L-sorbose | ||||||
Components | Gustatory receptor | ||||||
Keywords | TRANSPORT PROTEIN / Gustatory receptor / Ion channel / Sugar-binding / Fructose | ||||||
Function / homology | Function and homology information detection of chemical stimulus involved in sensory perception of sweet taste / ionotropic taste receptor activity / ligand-gated monoatomic cation channel activity / monoatomic cation transmembrane transport / signal transduction / plasma membrane Similarity search - Function | ||||||
Biological species | Bombyx mori (domestic silkworm) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.61 Å | ||||||
Authors | Gomes, J.V. / Butterwick, J.A. | ||||||
Funding support | 1items
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Citation | Journal: Nature / Year: 2024 Title: The molecular basis of sugar detection by an insect taste receptor. Authors: João Victor Gomes / Shivinder Singh-Bhagania / Matthew Cenci / Carlos Chacon Cordon / Manjodh Singh / Joel A Butterwick / Abstract: Animals crave sugars because of their energy potential and the pleasurable sensation of tasting sweetness. Yet all sugars are not metabolically equivalent, requiring mechanisms to detect and ...Animals crave sugars because of their energy potential and the pleasurable sensation of tasting sweetness. Yet all sugars are not metabolically equivalent, requiring mechanisms to detect and differentiate between chemically similar sweet substances. Insects use a family of ionotropic gustatory receptors to discriminate sugars, each of which is selectively activated by specific sweet molecules. Here, to gain insight into the molecular basis of sugar selectivity, we determined structures of Gr9, a gustatory receptor from the silkworm Bombyx mori (BmGr9), in the absence and presence of its sole activating ligand, D-fructose. These structures, along with structure-guided mutagenesis and functional assays, illustrate how D-fructose is enveloped by a ligand-binding pocket that precisely matches the overall shape and pattern of chemical groups in D-fructose. However, our computational docking and experimental binding assays revealed that other sugars also bind BmGr9, yet they are unable to activate the receptor. We determined the structure of BmGr9 in complex with one such non-activating sugar, L-sorbose. Although both sugars bind a similar position, only D-fructose is capable of engaging a bridge of two conserved aromatic residues that connects the pocket to the pore helix, inducing a conformational change that allows the ion-conducting pore to open. Thus, chemical specificity does not depend solely on the selectivity of the ligand-binding pocket, but it is an emergent property arising from a combination of receptor-ligand interactions and allosteric coupling. Our results support a model whereby coarse receptor tuning is derived from the size and chemical characteristics of the pocket, whereas fine-tuning of receptor activation is achieved through the selective engagement of an allosteric pathway that regulates ion conduction. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8vv3.cif.gz | 299.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8vv3.ent.gz | 244.6 KB | Display | PDB format |
PDBx/mmJSON format | 8vv3.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8vv3_validation.pdf.gz | 1.3 MB | Display | wwPDB validaton report |
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Full document | 8vv3_full_validation.pdf.gz | 1.3 MB | Display | |
Data in XML | 8vv3_validation.xml.gz | 58.7 KB | Display | |
Data in CIF | 8vv3_validation.cif.gz | 82.4 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/vv/8vv3 ftp://data.pdbj.org/pub/pdb/validation_reports/vv/8vv3 | HTTPS FTP |
-Related structure data
Related structure data | 43548MC 8uvtC 8uvuC C: citing same article (ref.) M: map data used to model this data |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 50677.070 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Bombyx mori (domestic silkworm) / Gene: Gr9, 100174818 / Production host: Homo sapiens (human) / References: UniProt: B3GTD7 #2: Sugar | ChemComp-SOE / Has ligand of interest | Y | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Homotetramer of Gr9 bound to L-sorbose / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: Bombyx mori (domestic silkworm) |
Source (recombinant) | Organism: Homo sapiens (human) |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 800 nm |
Image recording | Electron dose: 30 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
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3D reconstruction | Resolution: 2.61 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 920021 / Symmetry type: POINT | ||||||||||||||||||||||||
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