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Open data
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Basic information
| Entry | ![]() | |||||||||
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| Title | Consensus map of A2AR-beta-lactamase fusion + BLIPII | |||||||||
Map data | Consensus map | |||||||||
Sample |
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Keywords | G-protein coupled receptor / GPCR / fusion tag / MEMBRANE PROTEIN | |||||||||
| Biological species | other entries (others) / Streptomyces exfoliatus (bacteria) / Homo sapiens (human) / ![]() | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.22 Å | |||||||||
Authors | Shah NR / Bisson C / Hutchin A / McFarlane CR / Oosterlaken M / Pavic A / Zebisch M | |||||||||
| Funding support | 1 items
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Citation | Journal: Acta Crystallogr D Struct Biol / Year: 2026Title: A novel fusion tool to enable G protein-coupled receptor structure determination. Authors: Nita R Shah / Mathieu Oosterlaken / Claudine Bisson / Mattia Bertinelli / Alicia M Churchill-Angus / Andrew Hutchin / Jola Kopec / Vadim Kotov / Ciaran R McFarlane / Erika Griss Pascualli / ...Authors: Nita R Shah / Mathieu Oosterlaken / Claudine Bisson / Mattia Bertinelli / Alicia M Churchill-Angus / Andrew Hutchin / Jola Kopec / Vadim Kotov / Ciaran R McFarlane / Erika Griss Pascualli / Ana Pavic / Matthias Zebisch / Cédric Fiez-Vandal / Edoardo Fabini / Stéphanie Duclos / ![]() Abstract: Structure determination of G protein-coupled receptors (GPCRs) plays an important role in accelerating drug development against this medically important protein family. This study outlines the ...Structure determination of G protein-coupled receptors (GPCRs) plays an important role in accelerating drug development against this medically important protein family. This study outlines the development of a new fusion tool to enable structure determination of GPCRs in inactive conformations by cryo-EM. Initially, a PDB mining approach was applied to select eight naturally occurring proteins with the intention of fusing them into the intracellular loop 3 (ICL3) of GPCRs to create a suitable fiducial marker for cryo-EM workflows. During the selection process, candidates with known high-affinity protein binders were prioritized to enable a further increase in the protein mass of the fiducial marker. Fusion constructs were generated with adenosine receptor A (AR) and were assessed for expression and aggregation levels. For the two best-performing new fusion constructs, ligand binding was characterized to ensure that the fusion tag did not significantly affect protein behaviour. AR with a β-lactamase fusion in ICL3 and binding partner β-lactamase inhibitory protein II (BLIPII) was then selected to solve an antagonist-bound structure. The overall map was resolved to an average of 3.2 Å resolution with continuous helices connecting the β-lactamase to helices 5 and 6 of AR. Focused refinement of the AR region improved the local resolution and map detail in the orthosteric site, thereby allowing confident modelling of the antagonist ligand, ZM241385, which matches previously described X-ray crystallographic structures. This new fusion provides an alternative option for GPCR structure determination, with several potential benefits compared with existing tools, such as a more favourable position relative to the GPCR to reduce potential clashes. | |||||||||
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Structure visualization
| Supplemental images |
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Downloads & links
-EMDB archive
| Map data | emd_56449.map.gz | 166.1 MB | EMDB map data format | |
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| Header (meta data) | emd-56449-v30.xml emd-56449.xml | 20.7 KB 20.7 KB | Display Display | EMDB header |
| Images | emd_56449.png | 66.8 KB | ||
| Filedesc metadata | emd-56449.cif.gz | 5.2 KB | ||
| Others | emd_56449_half_map_1.map.gz emd_56449_half_map_2.map.gz | 165 MB 165 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-56449 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-56449 | HTTPS FTP |
-Related structure data
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Map
| File | Download / File: emd_56449.map.gz / Format: CCP4 / Size: 178 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Annotation | Consensus map | ||||||||||||||||||||||||||||||||||||
| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.835 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
-Half map: #1
| File | emd_56449_half_map_1.map | ||||||||||||
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| Projections & Slices |
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| Density Histograms |
-Half map: #2
| File | emd_56449_half_map_2.map | ||||||||||||
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| Projections & Slices |
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| Density Histograms |
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Sample components
-Entire : A2AR-beta-lactamase fusion, BLIPII, ZM241385
| Entire | Name: A2AR-beta-lactamase fusion, BLIPII, ZM241385 |
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| Components |
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-Supramolecule #1: A2AR-beta-lactamase fusion, BLIPII, ZM241385
| Supramolecule | Name: A2AR-beta-lactamase fusion, BLIPII, ZM241385 / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#2 Details: Complex of BLIPII bound to the beta-lactamase region of the chimeric A2AR-beta-lactamase fusion protein |
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| Source (natural) | Organism: other entries (others) |
-Supramolecule #2: A2AR-beta-lactamase fusion
| Supramolecule | Name: A2AR-beta-lactamase fusion / type: complex / ID: 2 / Parent: 1 / Macromolecule list: #1 Details: beta-lactamase fused into intracellular loop 3 of A2AR |
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| Source (natural) | Organism: other entries (others) |
-Supramolecule #3: beta-lactamase inhibitory protein II (BLIPII)
| Supramolecule | Name: beta-lactamase inhibitory protein II (BLIPII) / type: complex / ID: 3 / Parent: 1 / Macromolecule list: #2 |
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| Source (natural) | Organism: Streptomyces exfoliatus (bacteria) |
-Supramolecule #4: adenosine receptor A2a (A2AR)
| Supramolecule | Name: adenosine receptor A2a (A2AR) / type: complex / ID: 4 / Parent: 2 / Macromolecule list: #1 |
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| Source (natural) | Organism: Homo sapiens (human) |
-Supramolecule #5: beta-lactamase
| Supramolecule | Name: beta-lactamase / type: complex / ID: 5 / Parent: 2 / Macromolecule list: #1 |
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| Source (natural) | Organism: ![]() |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Concentration | 0.38 mg/mL | ||||||||||
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| Buffer | pH: 7.5 Component:
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| Grid | Model: UltrAuFoil R1.2/1.3 / Support film - Material: GOLD / Support film - topology: HOLEY | ||||||||||
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / Chamber temperature: 277.15 K / Instrument: FEI VITROBOT MARK IV | ||||||||||
| Details | Complex was formed and isolated by size exclusion chromatography |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average exposure time: 2.1 sec. / Average electron dose: 49.71 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | C2 aperture diameter: 50.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.3000000000000003 µm / Nominal defocus min: 1.1 µm / Nominal magnification: 105000 |
| Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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About Yorodumi




Keywords
Streptomyces exfoliatus (bacteria)
Homo sapiens (human)
Authors
Citation





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Processing
FIELD EMISSION GUN


