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Open data
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Basic information
Entry | Database: PDB / ID: 9bhu | ||||||
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Title | Streptomyces griseus Family 2B encapsulin shell | ||||||
![]() | Nucleotide-binding protein | ||||||
![]() | VIRUS LIKE PARTICLE / Encapsulin / nanocompartment | ||||||
Function / homology | ![]() | ||||||
Biological species | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.71 Å | ||||||
![]() | Andreas, M.P. / Giessen, T.W. | ||||||
Funding support | ![]()
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![]() | ![]() Title: The biosynthesis of the odorant 2-methylisoborneol is compartmentalized inside a protein shell. Authors: Michael P Andreas / Tobias W Giessen / ![]() Abstract: Terpenoids are the largest class of natural products, found across all domains of life. One of the most abundant bacterial terpenoids is the volatile odorant 2-methylisoborneol (2-MIB), partially ...Terpenoids are the largest class of natural products, found across all domains of life. One of the most abundant bacterial terpenoids is the volatile odorant 2-methylisoborneol (2-MIB), partially responsible for the earthy smell of soil and musty taste of contaminated water. Many bacterial 2-MIB biosynthetic gene clusters were thought to encode a conserved transcription factor, named EshA in the model soil bacterium Streptomyces griseus. Here, we revise the function of EshA, now referred to as Sg Enc, and show that it is a Family 2B encapsulin shell protein. Using cryo-electron microscopy, we find that Sg Enc forms an icosahedral protein shell and encapsulates 2-methylisoborneol synthase (2-MIBS) as a cargo protein. Sg Enc contains a cyclic adenosine monophosphate (cAMP) binding domain (CBD)-fold insertion and a unique metal-binding domain, both displayed on the shell exterior. We show that Sg Enc CBDs do not bind cAMP. We find that 2-MIBS cargo loading is mediated by an N-terminal disordered cargo-loading domain and that 2-MIBS activity and Sg Enc shell structure are not modulated by cAMP. Our work redefines the function of EshA and establishes Family 2B encapsulins as cargo-loaded protein nanocompartments involved in secondary metabolite biosynthesis. | ||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 85.5 KB | Display | ![]() |
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PDB format | ![]() | 63 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 1.4 MB | Display | ![]() |
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Full document | ![]() | 1.4 MB | Display | |
Data in XML | ![]() | 34 KB | Display | |
Data in CIF | ![]() | 45.9 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 44553MC ![]() 9bhvC ![]() 9bi0C M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Symmetry | Point symmetry: (Schoenflies symbol: I (icosahedral)) |
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Components
#1: Protein | Mass: 52014.137 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Details: Residues 1-39, 147-152, and 216-245 are unresolved in the map. Source: (gene. exp.) ![]() Gene: mmpI_1, NCTC13033_02226 / Production host: ![]() ![]() |
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#2: Chemical | ChemComp-CA / |
Has ligand of interest | Y |
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
Component | Name: Streptomyces griseus Family 2B encapsulin shell / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT | |||||||||||||||
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Molecular weight | Experimental value: NO | |||||||||||||||
Source (natural) | Organism: ![]() | |||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | |||||||||||||||
Buffer solution | pH: 7.5 / Details: 150 mM NaCl, 20 mM Tris pH 7.5 | |||||||||||||||
Buffer component |
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Specimen | Conc.: 2.5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||
Specimen support | Details: 60 seconds at 5 mA under vacuum / Grid material: COPPER / Grid mesh size: 200 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 295 K / Details: Blot force: 20 Blot time: 4 seconds |
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Electron microscopy imaging
Microscopy | Model: TFS GLACIOS |
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Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 45000 X / Nominal defocus max: 1800 nm / Nominal defocus min: 1000 nm |
Image recording | Average exposure time: 5 sec. / Electron dose: 43.22 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Num. of grids imaged: 1 |
Image scans | Width: 3710 / Height: 3838 / Movie frames/image: 25 |
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Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 159394 | ||||||||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: I (icosahedral) | ||||||||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 2.71 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 135027 Details: Homogeneous refinement with I symmetry imposed, per-particle defocus optimization, per-group CTF parameterization, spherical aberration fit enabled, tetrafoil fit enabled, Ewald sphere ...Details: Homogeneous refinement with I symmetry imposed, per-particle defocus optimization, per-group CTF parameterization, spherical aberration fit enabled, tetrafoil fit enabled, Ewald sphere correction with negative curvature, and minimize over per-particle scale enabled. Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 127.9 / Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: cross-correlation coefficient Details: An AlphaFold-generated model was fit into the map using ChimeraX v1.5. The model was then refined iteratively by alternating rounds of manual refinement in Coot v8.9.1 and real-space ...Details: An AlphaFold-generated model was fit into the map using ChimeraX v1.5. The model was then refined iteratively by alternating rounds of manual refinement in Coot v8.9.1 and real-space refinements using PHENIX v1.20.1-4487. | ||||||||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | Accession code: Q54255 / Source name: AlphaFold / Type: in silico model |