[English] 日本語
Yorodumi- PDB-9mbq: Substrate-engaged human 26S proteasome bound to midnolin with RPT... -
+
Open data
-
Basic information
| Entry | Database: PDB / ID: 9mbq | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Title | Substrate-engaged human 26S proteasome bound to midnolin with RPT5 at top of spiral staircase | |||||||||||||||||||||
Components |
| |||||||||||||||||||||
Keywords | HYDROLASE / Midnolin / 26S proteasome / Complex | |||||||||||||||||||||
| Function / homology | Function and homology informationRegulation of ornithine decarboxylase (ODC) / Proteasome assembly / Cross-presentation of soluble exogenous antigens (endosomes) / Autodegradation of Cdh1 by Cdh1:APC/C / APC/C:Cdc20 mediated degradation of Securin / APC/C:Cdh1 mediated degradation of Cdc20 and other APC/C:Cdh1 targeted proteins in late mitosis/early G1 / Cdc20:Phospho-APC/C mediated degradation of Cyclin A / Autodegradation of the E3 ubiquitin ligase COP1 / Asymmetric localization of PCP proteins / Degradation of AXIN ...Regulation of ornithine decarboxylase (ODC) / Proteasome assembly / Cross-presentation of soluble exogenous antigens (endosomes) / Autodegradation of Cdh1 by Cdh1:APC/C / APC/C:Cdc20 mediated degradation of Securin / APC/C:Cdh1 mediated degradation of Cdc20 and other APC/C:Cdh1 targeted proteins in late mitosis/early G1 / Cdc20:Phospho-APC/C mediated degradation of Cyclin A / Autodegradation of the E3 ubiquitin ligase COP1 / Asymmetric localization of PCP proteins / Degradation of AXIN / Degradation of DVL / Hedgehog ligand biogenesis / Hedgehog 'on' state / TNFR2 non-canonical NF-kB pathway / Assembly of the pre-replicative complex / CDK-mediated phosphorylation and removal of Cdc6 / G2/M Checkpoints / Ubiquitin-Mediated Degradation of Phosphorylated Cdc25A / Ubiquitin-dependent degradation of Cyclin D / RUNX1 regulates transcription of genes involved in differentiation of HSCs / Regulation of RUNX3 expression and activity / Regulation of PTEN stability and activity / KEAP1-NFE2L2 pathway / Degradation of CDH1 / Degradation of CRY and PER proteins / Activation of NF-kappaB in B cells / Oxygen-dependent proline hydroxylation of Hypoxia-inducible Factor Alpha / SCF(Skp2)-mediated degradation of p27/p21 / FCERI mediated NF-kB activation / Dectin-1 mediated noncanonical NF-kB signaling / CLEC7A (Dectin-1) signaling / Degradation of GLI1 by the proteasome / NIK-->noncanonical NF-kB signaling / Orc1 removal from chromatin / FBXL7 down-regulates AURKA during mitotic entry and in early mitosis / Regulation of RUNX2 expression and activity / Interleukin-1 signaling / GSK3B and BTRC:CUL1-mediated-degradation of NFE2L2 / Degradation of beta-catenin by the destruction complex / Neddylation / negative regulation of glucokinase activity / Antigen processing: Ubiquitination & Proteasome degradation / UCH proteinases / Downstream TCR signaling / AUF1 (hnRNP D0) binds and destabilizes mRNA / Ub-specific processing proteases / The role of GTSE1 in G2/M progression after G2 checkpoint / ABC-family protein mediated transport / Separation of Sister Chromatids / MAPK6/MAPK4 signaling / GLI3 is processed to GLI3R by the proteasome / thyrotropin-releasing hormone receptor binding / Impaired BRCA2 translocation to the nucleus / Impaired BRCA2 binding to SEM1 (DSS1) / host-mediated perturbation of viral transcription / integrator complex / proteasome accessory complex / meiosis I / purine ribonucleoside triphosphate binding / proteasome regulatory particle / cytosolic proteasome complex / positive regulation of proteasomal protein catabolic process / proteasome-activating activity / Antigen processing: Ub, ATP-independent proteasomal degradation / proteasome regulatory particle, lid subcomplex / proteasome regulatory particle, base subcomplex / sperm glycocalyx / protein K63-linked deubiquitination / metal-dependent deubiquitinase activity / Regulation of ornithine decarboxylase (ODC) / Proteasome assembly / proteasome core complex / perinuclear theca / Cross-presentation of soluble exogenous antigens (endosomes) / Somitogenesis / K63-linked deubiquitinase activity / Homologous DNA Pairing and Strand Exchange / Defective homologous recombination repair (HRR) due to BRCA1 loss of function / Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA1 binding function / Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA2/RAD51/RAD51C binding function / Resolution of D-loop Structures through Synthesis-Dependent Strand Annealing (SDSA) / Resolution of D-loop Structures through Holliday Junction Intermediates / proteasome binding / Impaired BRCA2 binding to RAD51 / myofibril / regulation of protein catabolic process / proteasome storage granule / proteasomal ubiquitin-independent protein catabolic process / sperm head-tail coupling apparatus / general transcription initiation factor binding / Presynaptic phase of homologous DNA pairing and strand exchange / blastocyst development / protein deubiquitination / polyubiquitin modification-dependent protein binding / immune system process / proteasome endopeptidase complex / NF-kappaB binding / proteasome core complex, beta-subunit complex / endopeptidase activator activity / threonine-type endopeptidase activity Similarity search - Function | |||||||||||||||||||||
| Biological species | Homo sapiens (human) | |||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.08 Å | |||||||||||||||||||||
Authors | Zhu, C. / Qin, L. / Liang, L. | |||||||||||||||||||||
| Funding support | China, 1items
| |||||||||||||||||||||
Citation | Journal: Nat Commun / Year: 2026Title: Structural dynamics of the midnolin-proteasome during ubiquitin-independent substrate turnover. Authors: Chuanda Zhu / Lu Qin / Zonglin Dai / Peng Zuo / Ao Yang / Lijun Zhong / Zhiqiang Lin / Ling Liang / ![]() Abstract: The 26S proteasome typically degrades proteins marked by ubiquitin chains. However, a distinct, ubiquitin-independent degradation pathway for nuclear proteins exists, mediated by the adaptor protein ...The 26S proteasome typically degrades proteins marked by ubiquitin chains. However, a distinct, ubiquitin-independent degradation pathway for nuclear proteins exists, mediated by the adaptor protein midnolin, yet its molecular mechanism remains poorly understood. Here, we present nine cryo-electron microscopy structures of the human 26S proteasome in complex with midnolin, which collectively delineate a near-complete catalytic cycle. Our structures reveal that midnolin binds to the proteasome via the RPN1 subunit by its C-terminal helix. Unexpectedly, its ubiquitin-like domain interacts with the RPN11 deubiquitinase in a non-catalytic role. This interaction positions the adjacent Catch domain, which is responsible for substrate binding, directly above the proteasomal entrance, potentially facilitating substrate entry into the proteasome. Furthermore, we observe four consecutive spiral staircase conformations of the AAA+ ATPase hexamer during substrate translocation. These findings provide insights into the mechanisms underlying ubiquitin-independent nuclear protein degradation and may help develop strategies for targeting nuclear proteins via direct proteasomal degradation. | |||||||||||||||||||||
| History |
|
-
Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
|---|
-
Downloads & links
-
Download
| PDBx/mmCIF format | 9mbq.cif.gz | 2.6 MB | Display | PDBx/mmCIF format |
|---|---|---|---|---|
| PDB format | pdb9mbq.ent.gz | Display | PDB format | |
| PDBx/mmJSON format | 9mbq.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/mb/9mbq ftp://data.pdbj.org/pub/pdb/validation_reports/mb/9mbq | HTTPS FTP |
|---|
-Related structure data
| Related structure data | ![]() 63777MC ![]() 22mmC ![]() 9mboC ![]() 9mbpC ![]() 9u3lC ![]() 9u4mC ![]() 9u7rC ![]() 9w39C ![]() 9wbgC C: citing same article ( M: map data used to model this data |
|---|---|
| Similar structure data | Similarity search - Function & homology F&H Search |
-
Links
-
Assembly
| Deposited unit | ![]()
|
|---|---|
| 1 |
|
-
Components
-26S proteasome non-ATPase regulatory subunit ... , 11 types, 11 molecules UVWXYZabcdx
| #1: Protein | Mass: 102404.375 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: Q99460 |
|---|---|
| #2: Protein | Mass: 54755.656 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: O43242 |
| #3: Protein | Mass: 52979.359 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: O00232 |
| #4: Protein | Mass: 47526.688 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: O00231 |
| #5: Protein | Mass: 45592.285 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: Q15008 |
| #6: Protein | Mass: 37086.441 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P51665 |
| #7: Protein | Mass: 42995.359 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: Q9UNM6 |
| #8: Protein | Mass: 40781.590 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P55036 |
| #9: Protein | Mass: 34620.023 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human)References: UniProt: O00487, Hydrolases; Acting on peptide bonds (peptidases); Omega peptidases |
| #10: Protein | Mass: 39667.871 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P48556 |
| #33: Protein | Mass: 100313.625 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: Q13200 |
-Protein , 3 types, 4 molecules eLlf
| #11: Protein | Mass: 8284.611 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P60896 | ||
|---|---|---|---|
| #23: Protein | Mass: 30150.277 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P25786#32: Protein | | Mass: 49278.652 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: Q504T8 |
-26S proteasome regulatory subunit ... , 6 types, 6 molecules ABCDEF
| #12: Protein | Mass: 48700.805 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P35998 |
|---|---|
| #13: Protein | Mass: 49260.504 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P62191 |
| #14: Protein | Mass: 45694.047 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P62194 |
| #15: Protein | Mass: 47426.141 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P43686 |
| #16: Protein | Mass: 44241.008 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P62335 |
| #17: Protein | Mass: 49266.457 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P17980 |
-Proteasome subunit alpha type- ... , 6 types, 12 molecules GgHhIiJjKkMm
| #18: Protein | Mass: 27301.262 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P60900#19: Protein | Mass: 25796.338 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P25787#20: Protein | Mass: 29394.648 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P25789#21: Protein | Mass: 27798.695 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: O14818#22: Protein | Mass: 26304.779 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P28066#24: Protein | Mass: 28338.057 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P25788 |
|---|
-Proteasome subunit beta type- ... , 7 types, 14 molecules NnOoPpQqRrSsTt
| #25: Protein | Mass: 25246.455 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human)References: UniProt: P28072, proteasome endopeptidase complex #26: Protein | Mass: 29869.223 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human)References: UniProt: Q99436, proteasome endopeptidase complex #27: Protein | Mass: 22841.701 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P49720#28: Protein | Mass: 22864.277 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P49721#29: Protein | Mass: 28379.053 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human)References: UniProt: P28074, proteasome endopeptidase complex #30: Protein | Mass: 26391.201 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P20618#31: Protein | Mass: 29099.986 Da / Num. of mol.: 2 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) / References: UniProt: P28070 |
|---|
-Protein/peptide , 1 types, 1 molecules v
| #34: Protein/peptide | Mass: 1209.482 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Homo sapiens (human) |
|---|
-Non-polymers , 5 types, 17 molecules 








| #35: Chemical | ChemComp-ZN / | ||||||
|---|---|---|---|---|---|---|---|
| #36: Chemical | ChemComp-ATP / #37: Chemical | ChemComp-MG / #38: Chemical | #39: Chemical | ChemComp-LDZ / |
-Details
| Has ligand of interest | Y |
|---|---|
| Has protein modification | N |
-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
|---|---|
| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-
Sample preparation
| Component | Name: 26S proteasome complexed with midnolin / Type: COMPLEX / Entity ID: #1-#34 / Source: MULTIPLE SOURCES |
|---|---|
| Molecular weight | Experimental value: NO |
| Source (natural) | Organism: Homo sapiens (human) |
| Buffer solution | pH: 7.4 |
| 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 |
|---|---|
| Microscopy | Model: TFS KRIOS |
| Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 1800 nm / Nominal defocus min: 800 nm |
| Image recording | Electron dose: 40 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-
Processing
| EM software |
| ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||
| 3D reconstruction | Resolution: 3.08 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 23186 / Symmetry type: POINT |
Movie
Controller
About Yorodumi



Homo sapiens (human)
China, 1items
Citation






















PDBj













FIELD EMISSION GUN