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Open data
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Basic information
| Entry | Database: PDB / ID: 9lol | ||||||||||||
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| Title | Cryo-EM structure of human MON1A-CCZ1-RAB7A | ||||||||||||
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Keywords | PROTEIN TRANSPORT / Complex / GEF / RAB-GTPase | ||||||||||||
| Function / homology | Function and homology informationMon1-Ccz1 complex / phagosome acidification / lipophagy / protein to membrane docking / positive regulation of viral process / epidermal growth factor catabolic process / synaptic vesicle recycling via endosome / negative regulation of intralumenal vesicle formation / alveolar lamellar body / Suppression of autophagy ...Mon1-Ccz1 complex / phagosome acidification / lipophagy / protein to membrane docking / positive regulation of viral process / epidermal growth factor catabolic process / synaptic vesicle recycling via endosome / negative regulation of intralumenal vesicle formation / alveolar lamellar body / Suppression of autophagy / phagosome-lysosome fusion / negative regulation of exosomal secretion / lysosome to ER cholesterol transport / retromer complex binding / phagosome maturation / presynaptic endosome / endosome to plasma membrane protein transport / vacuolar transport / protein localization to lysosome / early endosome to late endosome transport / positive regulation of exosomal secretion / phagophore assembly site membrane / melanosome membrane / RAB geranylgeranylation / bone resorption / protein targeting to lysosome / protein targeting to vacuole / RAB GEFs exchange GTP for GDP on RABs / RHOD GTPase cycle / TBC/RABGAPs / retrograde transport, endosome to Golgi / RHOF GTPase cycle / endosome to lysosome transport / RHOJ GTPase cycle / RHOQ GTPase cycle / protein secretion / CDC42 GTPase cycle / autophagosome membrane / RHOG GTPase cycle / RHOH GTPase cycle / RAC3 GTPase cycle / viral release from host cell / RAC2 GTPase cycle / response to bacterium / autophagosome assembly / lipid catabolic process / vesicle-mediated transport / RAC1 GTPase cycle / cholesterol homeostasis / phagocytic vesicle / MHC class II antigen presentation / guanyl-nucleotide exchange factor activity / Prevention of phagosomal-lysosomal fusion / secretory granule membrane / lipid droplet / small monomeric GTPase / endocytosis / mitochondrial membrane / small GTPase binding / phagocytic vesicle membrane / positive regulation of protein catabolic process / GDP binding / synaptic vesicle membrane / late endosome / late endosome membrane / protein transport / G protein activity / lysosome / endosome membrane / lysosomal membrane / GTPase activity / Neutrophil degranulation / GTP binding / protein-containing complex / mitochondrion / extracellular exosome / plasma membrane / cytosol Similarity search - Function | ||||||||||||
| Biological species | Homo sapiens (human) | ||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / negative staining / Resolution: 2.85 Å | ||||||||||||
Authors | Li, X. / Li, D. / Tang, D. / Wang, J. / Qi, S. | ||||||||||||
| Funding support | China, 3items
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Citation | Journal: Life Metab / Year: 2025Title: Cryo-EM structure of the human MON1A-CCZ1-RAB7A complex provides insights into nucleotide exchange mechanism. Authors: Xinna Li / Dan Li / Dan Tang / Xiaofang Huang / Hui Bao / Jiawei Wang / Shiqian Qi / ![]() Abstract: Autophagy is a fundamental cellular process, conserved across species from yeast to mammals, that plays a crucial role in maintaining cellular homeostasis. The functionally conserved MON1-CCZ1 (MC1) ...Autophagy is a fundamental cellular process, conserved across species from yeast to mammals, that plays a crucial role in maintaining cellular homeostasis. The functionally conserved MON1-CCZ1 (MC1) complex serves as a guanine nucleotide exchange factor (GEF) for the RAB GTPase RAB7A and is indispensable for directing RAB7A recruitment to autophagosome or lysosomal membranes. Despite its critical role, the precise molecular mechanism underlying the assembly of the human MON1A-CCZ1 (HsMC1) complex and its specific GEF activity towards RAB7A has remained unclear. In this study, we report the high-resolution cryo-electron microscopy (cryo-EM) structure of the HsMC1 GEF domain in a complex with the nucleotide-free RAB7A at 2.85 Å resolution. Our structural data demonstrate that engagement with the HsMC1 complex induces marked conformational shifts in the phosphate-binding loop (P-loop) and Switch I/II regions of RAB7A. A striking feature of this complex is the direct interaction between the P-loop of RAB7A and CCZ1, a structural detail not previously observed. Furthermore, biochemical assays targeting residues within Interface I or II of the HsMC1-RAB7A complex highlight their critical role in mediating the interaction and suggest a unique mechanism for nucleotide exchange facilitated by the HsMC1 complex. These findings provide novel molecular insights into the functional mechanisms of the HsMC1-RAB7A complex, offering a robust structural framework to inform future investigations into disease-related targets and therapeutic development. | ||||||||||||
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Structure visualization
| Structure viewer | Molecule: Molmil Jmol/JSmol |
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Downloads & links
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Download
| PDBx/mmCIF format | 9lol.cif.gz | 213.7 KB | Display | PDBx/mmCIF format |
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| PDB format | pdb9lol.ent.gz | 166.1 KB | Display | PDB format |
| PDBx/mmJSON format | 9lol.json.gz | Tree view | PDBx/mmJSON format | |
| Others | Other downloads |
-Validation report
| Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/lo/9lol ftp://data.pdbj.org/pub/pdb/validation_reports/lo/9lol | HTTPS FTP |
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-Related structure data
| Related structure data | ![]() 63249MC M: map data used to model this data C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
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Assembly
| Deposited unit | ![]()
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Components
| #1: Protein | Mass: 55935.016 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: CCZ1B, C7orf28B / Production host: ![]() |
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| #2: Protein | Mass: 62206.281 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: MON1A, SAND1 / Production host: ![]() |
| #3: Protein | Mass: 23515.773 Da / Num. of mol.: 1 / Mutation: N125I Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: RAB7A, RAB7 / Production host: ![]() |
| Has protein modification | N |
-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY |
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| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
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| Buffer solution | pH: 8 | ||||||||||||||||||||||||||||||
| Specimen | Conc.: 0.42 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: YES / Vitrification applied: NO | ||||||||||||||||||||||||||||||
| EM staining | Type: NEGATIVE / Material: uranyl acetate | ||||||||||||||||||||||||||||||
| Specimen support | Grid material: GOLD / Grid mesh size: 300 divisions/in. |
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Electron microscopy imaging
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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| Microscopy | Model: TFS KRIOS |
| Electron gun | Electron source: OTHER / Accelerating voltage: 300 kV / Illumination mode: OTHER |
| Electron lens | Mode: OTHER / Nominal defocus max: 2500 nm / Nominal defocus min: 1500 nm |
| Image recording | Electron dose: 50 e/Å2 / Film or detector model: TFS FALCON 4i (4k x 4k) / Num. of real images: 6406 |
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Processing
| CTF correction | Type: NONE |
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| Particle selection | Num. of particles selected: 6406 |
| Symmetry | Point symmetry: C1 (asymmetric) |
| 3D reconstruction | Resolution: 2.85 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 4554171 / Num. of class averages: 1246669 / Symmetry type: POINT |
| Atomic model building | Protocol: AB INITIO MODEL |
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About Yorodumi




Homo sapiens (human)
China, 3items
Citation
PDBj





















