+
Open data
-
Basic information
Entry | Database: PDB / ID: 7xht | ||||||
---|---|---|---|---|---|---|---|
Title | Structure of the OgeuIscB-omega RNA-target DNA complex | ||||||
![]() |
| ||||||
![]() | RNA BINDING PROTEIN/RNA/DNA / CRISPR-Cas9 / RNP / RNA BINDING PROTEIN / RNA BINDING PROTEIN-RNA-DNA complex | ||||||
Function / homology | DNA / DNA (> 10) / RNA / RNA (> 10) / RNA (> 100)![]() | ||||||
Biological species | metagenome (others) synthetic construct (others) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.55 Å | ||||||
![]() | Kato, K. / Okazaki, O. / Isayama, Y. / Ishikawa, J. / Nishizawa, T. / Nishimasu, H. | ||||||
Funding support | ![]()
| ||||||
![]() | ![]() Title: Structure of the IscB-ωRNA ribonucleoprotein complex, the likely ancestor of CRISPR-Cas9. Authors: Kazuki Kato / Sae Okazaki / Soumya Kannan / Han Altae-Tran / F Esra Demircioglu / Yukari Isayama / Junichiro Ishikawa / Masahiro Fukuda / Rhiannon K Macrae / Tomohiro Nishizawa / Kira S ...Authors: Kazuki Kato / Sae Okazaki / Soumya Kannan / Han Altae-Tran / F Esra Demircioglu / Yukari Isayama / Junichiro Ishikawa / Masahiro Fukuda / Rhiannon K Macrae / Tomohiro Nishizawa / Kira S Makarova / Eugene V Koonin / Feng Zhang / Hiroshi Nishimasu / ![]() ![]() Abstract: Transposon-encoded IscB family proteins are RNA-guided nucleases in the OMEGA (obligate mobile element-guided activity) system, and likely ancestors of the RNA-guided nuclease Cas9 in the type II ...Transposon-encoded IscB family proteins are RNA-guided nucleases in the OMEGA (obligate mobile element-guided activity) system, and likely ancestors of the RNA-guided nuclease Cas9 in the type II CRISPR-Cas adaptive immune system. IscB associates with its cognate ωRNA to form a ribonucleoprotein complex that cleaves double-stranded DNA targets complementary to an ωRNA guide segment. Although IscB shares the RuvC and HNH endonuclease domains with Cas9, it is much smaller than Cas9, mainly due to the lack of the α-helical nucleic-acid recognition lobe. Here, we report the cryo-electron microscopy structure of an IscB protein from the human gut metagenome (OgeuIscB) in complex with its cognate ωRNA and a target DNA, at 2.6-Å resolution. This high-resolution structure reveals the detailed architecture of the IscB-ωRNA ribonucleoprotein complex, and shows how the small IscB protein assembles with the ωRNA and mediates RNA-guided DNA cleavage. The large ωRNA scaffold structurally and functionally compensates for the recognition lobe of Cas9, and participates in the recognition of the guide RNA-target DNA heteroduplex. These findings provide insights into the mechanism of the programmable DNA cleavage by the IscB-ωRNA complex and the evolution of the type II CRISPR-Cas9 effector complexes. | ||||||
History |
|
-
Structure visualization
Structure viewer | Molecule: ![]() ![]() |
---|
-
Downloads & links
-
Download
PDBx/mmCIF format | ![]() | 215.4 KB | Display | ![]() |
---|---|---|---|---|
PDB format | ![]() | 157.1 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 1.1 MB | Display | ![]() |
---|---|---|---|---|
Full document | ![]() | 1.1 MB | Display | |
Data in XML | ![]() | 30.2 KB | Display | |
Data in CIF | ![]() | 43.5 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 33198MC M: map data used to model this data C: citing same article ( |
---|---|
Similar structure data | Similarity search - Function & homology ![]() |
-
Links
-
Assembly
Deposited unit | ![]()
|
---|---|
1 |
|
-
Components
-DNA chain , 2 types, 2 molecules CD
#2: DNA chain | Mass: 15092.702 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
---|---|
#3: DNA chain | Mass: 4281.832 Da / Num. of mol.: 1 / Source method: obtained synthetically / Source: (synth.) synthetic construct (others) |
-RNA chain / Protein , 2 types, 2 molecules BA
#1: RNA chain | Mass: 73640.742 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) metagenome (others) / Production host: ![]() ![]() |
---|---|
#4: Protein | Mass: 56819.680 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) metagenome (others) / Production host: ![]() ![]() |
-Non-polymers , 2 types, 3 molecules 


#5: Chemical | #6: Chemical | ChemComp-LDA / | |
---|
-Details
Has ligand of interest | N |
---|
-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
---|---|
EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-
Sample preparation
Component |
| ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Molecular weight | Experimental value: NO | ||||||||||||||||||||||||
Source (natural) | Organism: metagenome (others) | ||||||||||||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | ||||||||||||||||||||||||
Buffer solution | pH: 7 | ||||||||||||||||||||||||
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | ||||||||||||||||||||||||
Vitrification | Cryogen name: ETHANE |
-
Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
---|---|
Microscopy | Model: TFS KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: DIFFRACTION / Nominal defocus max: 2000 nm / Nominal defocus min: 800 nm |
Image recording | Electron dose: 47.9 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-
Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
3D reconstruction | Resolution: 2.55 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 792405 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
|