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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 / neurotransmitter receptor transport, postsynaptic endosome to lysosome / epidermal growth factor catabolic process / synaptic vesicle recycling via endosome / negative regulation of intralumenal vesicle formation / alveolar lamellar body ...Mon1-Ccz1 complex / phagosome acidification / lipophagy / protein to membrane docking / positive regulation of viral process / neurotransmitter receptor transport, postsynaptic endosome to lysosome / 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 / establishment of vesicle localization / retromer complex binding / phagosome maturation / presynaptic endosome / endosome to plasma membrane protein transport / early endosome to late endosome transport / protein localization to lysosome / phagophore assembly site membrane / RAB geranylgeranylation / protein targeting to vacuole / positive regulation of exosomal secretion / melanosome membrane / protein targeting to lysosome / 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 / ciliary transition zone / CDC42 GTPase cycle / autophagosome membrane / RHOG GTPase cycle / viral release from host cell / RHOH GTPase cycle / protein secretion / RAC3 GTPase cycle / RAC2 GTPase cycle / bone resorption / autophagosome assembly / lipid catabolic process / phagocytic vesicle / vesicle-mediated transport / RAC1 GTPase cycle / MHC class II antigen presentation / lipid droplet / Prevention of phagosomal-lysosomal fusion / guanyl-nucleotide exchange factor activity / secretory granule membrane / small monomeric GTPase / response to bacterium / mitochondrial membrane / phagocytic vesicle membrane / small GTPase binding / endocytosis / positive regulation of protein catabolic process / GDP binding / late endosome / late endosome membrane / protein transport / synaptic vesicle membrane / G protein activity / lysosome / endosome membrane / lysosomal membrane / GTPase activity / Neutrophil degranulation / GTP binding / glutamatergic synapse / Golgi apparatus / 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
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