+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-30184 | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Title | EcoR124I-Ocr in the Translocation State | |||||||||
Map data | ||||||||||
Sample |
| |||||||||
Function / homology | Function and homology information type I site-specific deoxyribonuclease / type I site-specific deoxyribonuclease activity / N-methyltransferase activity / site-specific DNA-methyltransferase (adenine-specific) / site-specific DNA-methyltransferase (adenine-specific) activity / DNA restriction-modification system / methylation / DNA binding / ATP binding Similarity search - Function | |||||||||
Biological species | Escherichia coli (E. coli) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 6.17 Å | |||||||||
Authors | Gao Y / Gao P | |||||||||
Citation | Journal: Nat Microbiol / Year: 2020 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. | |||||||||
History |
|
-Structure visualization
Movie |
Movie viewer |
---|---|
Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_30184.map.gz | 58.9 MB | EMDB map data format | |
---|---|---|---|---|
Header (meta data) | emd-30184-v30.xml emd-30184.xml | 7.9 KB 7.9 KB | Display Display | EMDB header |
Images | emd_30184.png | 76.7 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-30184 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-30184 | HTTPS FTP |
-Validation report
Summary document | emd_30184_validation.pdf.gz | 78 KB | Display | EMDB validaton report |
---|---|---|---|---|
Full document | emd_30184_full_validation.pdf.gz | 77.2 KB | Display | |
Data in XML | emd_30184_validation.xml.gz | 495 B | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-30184 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-30184 | HTTPS FTP |
-Related structure data
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
---|
-Map
File | Download / File: emd_30184.map.gz / Format: CCP4 / Size: 64 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.35 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
|
-Supplemental data
-Sample components
-Entire : EcoR124I-Ocr
Entire | Name: EcoR124I-Ocr |
---|---|
Components |
|
-Supramolecule #1: EcoR124I-Ocr
Supramolecule | Name: EcoR124I-Ocr / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#4 |
---|---|
Source (natural) | Organism: Escherichia coli (E. coli) |
Recombinant expression | Organism: Escherichia coli (E. coli) |
-Experimental details
-Structure determination
Method | cryo EM |
---|---|
Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.5 |
---|---|
Vitrification | Cryogen name: ETHANE |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
---|---|
Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Average electron dose: 60.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 6.17 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 15240 |
---|---|
Initial angle assignment | Type: PROJECTION MATCHING |
Final angle assignment | Type: PROJECTION MATCHING |