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Open data
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Basic information
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Title | Catalytic domain of Dihydrolipoamide Succinytransferase | |||||||||
![]() | Sharpened map using DeepEMhancer | |||||||||
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![]() | E2 / 2-oxoglutarate dehydrogenase complex / catalytic domain / tricarboxylic acid cycle / TRANSFERASE | |||||||||
Function / homology | ![]() L-lysine catabolic process to acetyl-CoA via saccharopine / dihydrolipoyllysine-residue succinyltransferase / dihydrolipoyllysine-residue succinyltransferase activity / oxoglutarate dehydrogenase complex / tricarboxylic acid cycle / cytosol Similarity search - Function | |||||||||
Biological species | ![]() ![]() ![]() ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.51 Å | |||||||||
![]() | Carr KD / Borst AJ / Weidle C | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Protein identification using Cryo-EM and artificial intelligence guides improved sample purification. Authors: Kenneth D Carr / Dane Evan D Zambrano / Connor Weidle / Alex Goodson / Helen E Eisenach / Harley Pyles / Alexis Courbet / Neil P King / Andrew J Borst / ![]() Abstract: Protein purification is essential in protein biochemistry, structural biology, and protein design, enabling the determination of protein structures, the study of biological mechanisms, and the ...Protein purification is essential in protein biochemistry, structural biology, and protein design, enabling the determination of protein structures, the study of biological mechanisms, and the characterization of both natural and de novo designed proteins. However, standard purification strategies often encounter challenges, such as unintended co-purification of contaminants alongside the target protein. This issue is particularly problematic for self-assembling protein nanomaterials, where unexpected geometries may reflect novel assembly states, cross-contamination, or native proteins originating from the expression host. Here, we used an automated structure-to-sequence pipeline to first identify an unknown co-purifying protein found in several purified designed protein samples. By integrating cryo-electron microscopy (Cryo-EM), ModelAngelo's sequence-agnostic model-building, and Protein BLAST, we identified the contaminant as dihydrolipoamide succinyltransferase (DLST). This identification was validated through comparisons with DLST structures in the Protein Data Bank, AlphaFold 3 predictions based on the DLST sequence from our E. coli expression vector, and traditional biochemical methods. The identification informed subsequent modifications to our purification protocol, which successfully excluded DLST from future preparations. To explore the potential broader utility of this approach, we benchmarked four computational methods for DLST identification across varying resolution ranges. This study demonstrates the successful application of a structure-to-sequence protein identification workflow, integrating Cryo-EM, ModelAngelo, Protein BLAST, and AlphaFold 3 predictions, to identify and ultimately help guide the removal of DLST from sample purification efforts. It highlights the potential of combining Cryo-EM with AI-driven tools for accurate protein identification and addressing purification challenges across diverse contexts in protein science. | |||||||||
History |
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Structure visualization
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Downloads & links
-EMDB archive
Map data | ![]() | 23.1 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 27.1 KB 27.1 KB | Display Display | ![]() |
FSC (resolution estimation) | ![]() | 19.7 KB | Display | ![]() |
Images | ![]() | 184.7 KB | ||
Filedesc metadata | ![]() | 6.7 KB | ||
Others | ![]() ![]() ![]() ![]() | 412.5 MB 777.5 MB 762.9 MB 762.8 MB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Validation report
Summary document | ![]() | 815.6 KB | Display | ![]() |
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Full document | ![]() | 815 KB | Display | |
Data in XML | ![]() | 28.5 KB | Display | |
Data in CIF | ![]() | 37.6 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 9dz8MC M: atomic model generated by this map C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
EMDB pages | ![]() ![]() |
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Related items in Molecule of the Month |
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Map
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Annotation | Sharpened map using DeepEMhancer | ||||||||||||||||||||
Voxel size | X=Y=Z: 0.84 Å | ||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
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Sample components
-Entire : Dihydrolipoamide Succinyltransferase
Entire | Name: Dihydrolipoamide Succinyltransferase |
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Components |
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-Supramolecule #1: Dihydrolipoamide Succinyltransferase
Supramolecule | Name: Dihydrolipoamide Succinyltransferase / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 Details: This protein was observed as contaminant in a sample of a two component nanoparticle assembly. |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 1.056 MDa |
-Macromolecule #1: Dihydrolipoyllysine-residue succinyltransferase component of 2-ox...
Macromolecule | Name: Dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex type: protein_or_peptide / ID: 1 / Number of copies: 24 / Enantiomer: LEVO / EC number: dihydrolipoyllysine-residue succinyltransferase |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 26.10742 KDa |
Sequence | String: ARSEKRVPMT RLRKRVAERL LEAKNSTAML TTFNEVNMKP IMDLRKQYGE AFEKRHGIRL GFMSFYVKAV VEALKRYPEV NASIDGDDV VYHNYFDVSM AVSTPRGLVT PVLRDVDTLG MADIEKKIKE LAVKGRDGKL TVEDLTGGNF TITNGGVFGS L MSTPIINP ...String: ARSEKRVPMT RLRKRVAERL LEAKNSTAML TTFNEVNMKP IMDLRKQYGE AFEKRHGIRL GFMSFYVKAV VEALKRYPEV NASIDGDDV VYHNYFDVSM AVSTPRGLVT PVLRDVDTLG MADIEKKIKE LAVKGRDGKL TVEDLTGGNF TITNGGVFGS L MSTPIINP PQSAILGMHA IKDRPMAVNG QVEILPMMYL ALSYDHRLID GRESVGFLVT IKELLEDPTR LLLDV UniProtKB: Dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex |
-Macromolecule #2: water
Macromolecule | Name: water / type: ligand / ID: 2 / Number of copies: 2088 / Formula: HOH |
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Molecular weight | Theoretical: 18.015 Da |
Chemical component information | ![]() ChemComp-HOH: |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Concentration | 0.3 mg/mL |
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Buffer | pH: 8 |
Grid | Model: Quantifoil R2/2 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY / Support film - Film thickness: 40 / Pretreatment - Type: GLOW DISCHARGE |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 295.15 K / Instrument: FEI VITROBOT MARK IV Details: Wait time: 7.5 seconds Blot time: 0.5 seconds Blot force: 0 seconds. |
Details | This sample was heterogeneous and contamined both DLST and the designed nanoparticle assembly. |
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Electron microscopy
Microscope | TFS KRIOS |
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Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Digitization - Dimensions - Width: 5760 pixel / Digitization - Dimensions - Height: 4092 pixel / Number grids imaged: 1 / Number real images: 4264 / Average exposure time: 5.0 sec. / Average electron dose: 47.0 e/Å2 Details: 6211 movies were collected, the best 4264 were used for particle picking and further processing. |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 1.8 µm / Nominal defocus min: 0.8 µm |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
Initial model | Chain - Source name: Other / Chain - Initial model type: in silico model / Details: ModelAngelo |
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Details | The final model was built to density using the UniProt sequence in ModelAngelo. Further refinement of the model to the density was performed using ISOLDE in ChimeraX, Coot, Phenix. Waters were built to one chain and then that chain and water network were rebuilt in ChimeraX using symmetry. |
Refinement | Space: REAL / Protocol: OTHER / Overall B value: 69.9 / Target criteria: Cross-correlation coefficient |
Output model | ![]() PDB-9dz8: |