+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-42793 | ||||||||||||
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Title | Aquaporin Z with ALFA tag and bound to nanobody | ||||||||||||
Map data | EM map | ||||||||||||
Sample |
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Keywords | AqpZ / water channel / ALFA tag / cardiolipin / MEMBRANE PROTEIN | ||||||||||||
Function / homology | Function and homology information intracellular water homeostasis / water channel activity / water transport / response to osmotic stress / identical protein binding / plasma membrane Similarity search - Function | ||||||||||||
Biological species | Escherichia coli (E. coli) / Vicugna pacos (alpaca) | ||||||||||||
Method | single particle reconstruction / cryo EM / Resolution: 1.9 Å | ||||||||||||
Authors | Stover L / Bahramimoghaddam H / Wang L / Zhou M / Laganowsky A | ||||||||||||
Funding support | United States, 3 items
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Citation | Journal: J Struct Biol X / Year: 2024 Title: Grafting the ALFA tag for structural studies of aquaporin Z. Authors: Lauren Stover / Hanieh Bahramimoghaddam / Lie Wang / Samantha Schrecke / Gaya P Yadav / Ming Zhou / Arthur Laganowsky / Abstract: Aquaporin Z (AqpZ), a bacterial water channel, forms a tetrameric complex and, like many other membrane proteins, activity is regulated by lipids. Various methods have been developed to facilitate ...Aquaporin Z (AqpZ), a bacterial water channel, forms a tetrameric complex and, like many other membrane proteins, activity is regulated by lipids. Various methods have been developed to facilitate structure determination of membrane proteins, such as the use of antibodies. Here, we graft onto AqpZ the ALFA tag (AqpZ-ALFA), an alpha helical epitope, to make use of the high-affinity anti-ALFA nanobody (nB). Native mass spectrometry reveals the AqpZ-ALFA fusion forms a stable, 1:1 complex with nB. Single-particle cryogenic electron microscopy studies reveal the octameric (AqpZ-ALFA)(nB) complex forms a dimeric assembly and the structure was determined to 1.9 Å resolution. Dimerization of the octamer is mediated through stacking of the symmetrically bound nBs. Tube-like density is also observed, revealing a potential cardiolipin binding site. Grafting of the ALFA tag, or other epitope, along with binding and association of nBs to promote larger complexes will have applications in structural studies and protein engineering. | ||||||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_42793.map.gz | 82 MB | EMDB map data format | |
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Header (meta data) | emd-42793-v30.xml emd-42793.xml | 21.3 KB 21.3 KB | Display Display | EMDB header |
Images | emd_42793.png | 150.1 KB | ||
Filedesc metadata | emd-42793.cif.gz | 6.2 KB | ||
Others | emd_42793_additional_1.map.gz emd_42793_half_map_1.map.gz emd_42793_half_map_2.map.gz | 154.4 MB 151.5 MB 151.5 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-42793 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-42793 | HTTPS FTP |
-Validation report
Summary document | emd_42793_validation.pdf.gz | 848.3 KB | Display | EMDB validaton report |
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Full document | emd_42793_full_validation.pdf.gz | 847.8 KB | Display | |
Data in XML | emd_42793_validation.xml.gz | 14.8 KB | Display | |
Data in CIF | emd_42793_validation.cif.gz | 17.7 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-42793 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-42793 | HTTPS FTP |
-Related structure data
Related structure data | 8uy6MC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_42793.map.gz / Format: CCP4 / Size: 163.6 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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Annotation | EM map | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.832 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Sample components
-Entire : Aquaporin Z with ALFA tag bound to nanobody
Entire | Name: Aquaporin Z with ALFA tag bound to nanobody |
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Components |
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-Supramolecule #1: Aquaporin Z with ALFA tag bound to nanobody
Supramolecule | Name: Aquaporin Z with ALFA tag bound to nanobody / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#2 |
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Molecular weight | Theoretical: 161 KDa |
-Supramolecule #2: Aquaporin Z with ALFA tag
Supramolecule | Name: Aquaporin Z with ALFA tag / type: complex / ID: 2 / Parent: 1 / Macromolecule list: #1 |
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Source (natural) | Organism: Escherichia coli (E. coli) |
-Supramolecule #3: nanobody
Supramolecule | Name: nanobody / type: complex / ID: 3 / Parent: 1 / Macromolecule list: #2 |
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Source (natural) | Organism: Vicugna pacos (alpaca) |
-Macromolecule #1: Aquaporin Z
Macromolecule | Name: Aquaporin Z / type: protein_or_peptide / ID: 1 / Number of copies: 8 / Enantiomer: LEVO |
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Source (natural) | Organism: Escherichia coli (E. coli) |
Molecular weight | Theoretical: 26.710988 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | String: MFRKLAAECF GTFWLVFGGC GSAVLAAGFP ELGIGFAGVA LAFGLTVLTM AFAVGHISGG HFNPAVTIGL WAGGRFPAKE VVGYVIAQV VGGIVAAALL YLIASGKTGF DAAASGFASN GYGEHSPGGY SMLSALVVEL VLSAGFLLVI HGATDKFAPA G FAPIAIGL ...String: MFRKLAAECF GTFWLVFGGC GSAVLAAGFP ELGIGFAGVA LAFGLTVLTM AFAVGHISGG HFNPAVTIGL WAGGRFPAKE VVGYVIAQV VGGIVAAALL YLIASGKTGF DAAASGFASN GYGEHSPGGY SMLSALVVEL VLSAGFLLVI HGATDKFAPA G FAPIAIGL ALTLIHLISI PVTNTSVNPA RSTAVAIFQG GWALEQLWFF WVVPIVGGII GGLIYRTLLR ASRLEEELRR RL TEPGGGP GASWSHPQFE K UniProtKB: Aquaporin Z |
-Macromolecule #2: anti-ALFA nanobody
Macromolecule | Name: anti-ALFA nanobody / type: protein_or_peptide / ID: 2 / Number of copies: 8 / Enantiomer: LEVO |
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Source (natural) | Organism: Vicugna pacos (alpaca) |
Molecular weight | Theoretical: 13.599183 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | String: SGEVQLQESG GGLVQPGGSL RLSCTASGVT ISALNAMAMG WYRQAPGERR VMVAAVSERG NAMYRESVQG RFTVTRDFTN KMVSLQMDN LKPEDTAVYY CHVLEDRVDS FHDYWGQGTQ VTVSS |
-Macromolecule #3: CARDIOLIPIN
Macromolecule | Name: CARDIOLIPIN / type: ligand / ID: 3 / Number of copies: 8 / Formula: CDL |
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Molecular weight | Theoretical: 1.464043 KDa |
Chemical component information | ChemComp-CDL: |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 10 mg/mL |
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Buffer | pH: 7.4 / Details: 20mM TRIS pH 7.4, 100mM NaCl, and 0.5% C8E4 |
Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 60 sec. / Pretreatment - Atmosphere: OTHER |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 278 K / Instrument: FEI VITROBOT MARK IV |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 50.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: OTHER / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.5 µm / Nominal defocus min: 1.0 µm / Nominal magnification: 105000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |