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Open data
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Basic information
Entry | Database: PDB / ID: 7bst | ||||||
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Title | EcoR124I-Ocr in the Intermediate State | ||||||
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![]() | IMMUNE SYSTEM / Cryoelectron microscopy / Innate immune mechanism / Complex | ||||||
Function / homology | ![]() type I site-specific deoxyribonuclease / type I site-specific deoxyribonuclease activity / symbiont-mediated evasion of host restriction-modification system / N-methyltransferase activity / site-specific DNA-methyltransferase (adenine-specific) / site-specific DNA-methyltransferase (adenine-specific) activity / DNA restriction-modification system / methylation / virus-mediated perturbation of host defense response / DNA binding / ATP binding Similarity search - Function | ||||||
Biological species | ![]() ![]() ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 4.37 Å | ||||||
![]() | Gao, Y. / Gao, P. | ||||||
![]() | ![]() Title: Structural insights into assembly, operation and inhibition of a type I restriction-modification system. Authors: Yina Gao / Duanfang Cao / Jingpeng Zhu / Han Feng / Xiu Luo / Songqing Liu / Xiao-Xue Yan / Xinzheng Zhang / Pu Gao / ![]() Abstract: Type I restriction-modification (R-M) systems are widespread in prokaryotic genomes and provide robust protection against foreign DNA. They are multisubunit enzymes with methyltransferase, ...Type I restriction-modification (R-M) systems are widespread in prokaryotic genomes and provide robust protection against foreign DNA. They are multisubunit enzymes with methyltransferase, endonuclease and translocase activities. Despite extensive studies over the past five decades, little is known about the molecular mechanisms of these sophisticated machines. Here, we report the cryo-electron microscopy structures of the representative EcoR124I R-M system in different assemblies (RMS, RMS and MS) bound to target DNA and the phage and mobile genetic element-encoded anti-restriction proteins Ocr and ArdA. EcoR124I can precisely regulate different enzymatic activities by adopting distinct conformations. The marked conformational transitions of EcoR124I are dependent on the intrinsic flexibility at both the individual-subunit and assembled-complex levels. Moreover, Ocr and ArdA use a DNA-mimicry strategy to inhibit multiple activities, but do not block the conformational transitions of the complexes. These structural findings, complemented by mutational studies of key intermolecular contacts, provide insights into assembly, operation and inhibition mechanisms of type I R-M systems. | ||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 751.6 KB | Display | ![]() |
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PDB format | ![]() | 592 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 30166MC ![]() 7btoC ![]() 7btpC ![]() 7btqC ![]() 7btrC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 120278.859 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() References: UniProt: Q304R3, UniProt: P10486*PLUS, type I site-specific deoxyribonuclease #2: Protein | Mass: 58077.090 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() References: UniProt: P10484, site-specific DNA-methyltransferase (adenine-specific) #3: Protein | Mass: 13819.015 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() #4: Protein | | Mass: 46235.773 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() |
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-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: EcoR124I-Ocr / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company | ||||||||||||
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Microscopy | Model: FEI TITAN KRIOS | ||||||||||||
Electron gun | Electron source: ![]() | ||||||||||||
Electron lens | Mode: BRIGHT FIELD | ||||||||||||
Image recording |
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Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION |
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3D reconstruction | Resolution: 4.37 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 64585 / Symmetry type: POINT |