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Open data
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Basic information
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| Title | Consensus map of MIDN-bound 26S proteasome, EB-state | |||||||||
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Keywords | proteasome / MIDN / IMMUNE SYSTEM | |||||||||
| Biological species | Homo sapiens (human) | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 2.8 Å | |||||||||
Authors | Peddada N / Beutler B | |||||||||
| Funding support | United States, 2 items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2025Title: Structural insights into the ubiquitin-independent midnolin-proteasome pathway. Authors: Nagesh Peddada / Xue Zhong / Yan Yin / Danielle Renee Lazaro / Jianhui Wang / Stephen Lyon / Jin Huk Choi / Xiao-Chen Bai / Eva Marie Y Moresco / Bruce Beutler / ![]() Abstract: The protein midnolin (MIDN) augments proteasome activity in lymphocytes and dramatically facilitates the survival and proliferation of B-lymphoid malignancies. MIDN binds both to proteasomes and to ...The protein midnolin (MIDN) augments proteasome activity in lymphocytes and dramatically facilitates the survival and proliferation of B-lymphoid malignancies. MIDN binds both to proteasomes and to substrates, but the mode of interaction with the proteasome is unknown, and the mechanism by which MIDN facilitates substrate degradation in a ubiquitin-independent manner is incompletely understood. Here, we present cryoelectron microscopy (cryo-EM) structures of the substrate-engaged, MIDN-bound human proteasome in two conformational states. MIDN induces proteasome conformations similarly to ubiquitinated substrates by using its ubiquitin-like domain to bind to the deubiquitinase RPN11 (PSMD14). By simultaneously binding to RPN1 (PSMD2) with its C-terminal α-helix, MIDN positions its substrate-carrying Catch domain above the proteasome ATPase channel through which substrates are translocated before degradation. Our findings suggest that both ubiquitin-like domain and C-terminal α-helix must bind to the proteasome for MIDN to stimulate proteasome activity. | |||||||||
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Structure visualization
| Supplemental images |
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Downloads & links
-EMDB archive
| Map data | emd_49497.map.gz | 887.2 MB | EMDB map data format | |
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| Header (meta data) | emd-49497-v30.xml emd-49497.xml | 16.5 KB 16.5 KB | Display Display | EMDB header |
| FSC (resolution estimation) | emd_49497_fsc.xml | 21 KB | Display | FSC data file |
| Images | emd_49497.png | 105.4 KB | ||
| Filedesc metadata | emd-49497.cif.gz | 4.7 KB | ||
| Others | emd_49497_half_map_1.map.gz emd_49497_half_map_2.map.gz | 926.5 MB 926.5 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-49497 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-49497 | HTTPS FTP |
-Validation report
| Summary document | emd_49497_validation.pdf.gz | 858.7 KB | Display | EMDB validaton report |
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| Full document | emd_49497_full_validation.pdf.gz | 858.3 KB | Display | |
| Data in XML | emd_49497_validation.xml.gz | 31 KB | Display | |
| Data in CIF | emd_49497_validation.cif.gz | 41.3 KB | Display | |
| Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-49497 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-49497 | 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_49497.map.gz / Format: CCP4 / Size: 1000 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 1.074 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
-Half map: #1
| File | emd_49497_half_map_1.map | ||||||||||||
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-Half map: #2
| File | emd_49497_half_map_2.map | ||||||||||||
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| Density Histograms |
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Sample components
-Entire : MIDN-bound proteasome Eb-state
| Entire | Name: MIDN-bound proteasome Eb-state |
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| Components |
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-Supramolecule #1: MIDN-bound proteasome Eb-state
| Supramolecule | Name: MIDN-bound proteasome Eb-state / type: complex / ID: 1 / Parent: 0 |
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| Source (natural) | Organism: Homo sapiens (human) |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Buffer | pH: 7.6 Details: 50 mM Tris, pH 7.5, 150 mM NaCl, 20 mM KCl, 2 mM ATP-g-S, 5 mM MgCl2, 1 mM TECP |
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| Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Pretreatment - Type: GLOW DISCHARGE / Details: blot force of 14-16, blot time 4.0 |
| Vitrification | Cryogen name: ETHANE / Instrument: FEI VITROBOT MARK IV |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Specialist optics | Energy filter - Name: GIF Bioquantum |
| Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Number grids imaged: 3 / Number real images: 20794 / Average electron dose: 50.0 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | C2 aperture diameter: 70.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.7 µm / Nominal defocus min: 1.2 µm |
| Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
| Initial model | PDB ID: Chain - Source name: PDB / Chain - Initial model type: experimental model |
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| Refinement | Space: REAL / Protocol: RIGID BODY FIT |
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About Yorodumi




Keywords
Homo sapiens (human)
Authors
United States, 2 items
Citation
















Z (Sec.)
Y (Row.)
X (Col.)




































FIELD EMISSION GUN


